Cleaning Bristol Blenheim BL-106 rudder pedals for paintingKeskiviikko 10.12.2025 - Tuesday Club member https://www.ilmailumuseoyhdistys.fi/blogi/2025/12/10/49878Once the pilot's seat of the Bristol Blenheim BL-106 had been restored, we continued our work on the rudder pedals. The pedals themselves are not broken; but they are heavily soiled and the aluminium parts already display corrosion-induced pitting. The steel parts of the controls are covered in rust.
This time, we began the restoration by investigating how the rudder pedals had originally been surface-treated. It seemed that the aluminium parts of the pedals were simply bare aluminium. Their surface was distinctly greenish yellow. There were also traces of grey paint found on the surface of some parts.
We consulted the Finnish Air Force Museum about the colour of this aluminium. It turned out that the aluminium parts of the rudder pedals were zinc chromated. At the same time, we asked if it was possible to determine from the serial number (50966/1), stamped on the surface, whether the pedals were manufactured in England or Finland. The serial number revealed that these pedals were made by the Finnish State Aircraft Factory (Valtion lentokonetehdas). After the serial number, there was also a small VL logo.
The interior surfaces, seats, and controls of the cockpits of Blenheim bombers, manufactured or overhauled in Finland, were painted with VL’s standard grey paint in the RAL 7005 shade. Thus, the remnants of grey paint found on the rudder pedals of the BL-106 confirmed that the same practice had been applied to this particular aircraft. However, most of the original surface paint had already worn away.
We will paint the rudder pedals with Isoguard Pansar paint for metal surfaces, in the RAL 7005 grey shade. This paint is alkyd and linseed oil based. Before applying the grey topcoat, the steel parts of the rudder pedals will be treated with clear Isotrol lacquer. The aluminium parts will be painted directly with Isoguard Pansar paint. This was also the method we used when restoring the pilot’s seat. We began cleaning the rudder pedals of dirt, rust, and grease. The rusted steel components were mainly cleaned by mechanically grinding their corroded surfaces until they were clean. When cleaning the dirty surfaces of the aluminium parts, we first tried both Sinol and white spirit, but these were ineffective. We had to find a more suitable solvent.
We proceeded to use both Solmaster Painter's Solvent and CRC Brakleen Pro brake part cleaner. We applied these products to the various components, spreading the solvent onto the surface and into crevices with a brush. The solution was left to work for a while. After that, the surfaces were scrubbed using both soft brass and plastic brushes, and for tight gaps, even toothbrushes. A steel brush was not used, as it would have damaged the zinc chromated surface of the rudder pedals. After scrubbing, we wiped the surfaces with a cloth. The solvents proved effective at removing the sticky grease and dirt, although the treatment had to be repeated several times.
A small steam cleaner was also put into use. The surfaces were treated again with the solvents mentioned earlier and then "blasted" with the steam cleaner. The steam cleaner was very effective at removing grease and dirt, but it was not sufficiently effective against oxidised areas. After each steam cleaning, the part was wiped clean with a cloth. By repeating this method, the surfaces gradually became cleaner, as each time more dirt and remnants of old paint were removed. After using the solvents and the steam cleaner, patches of wear caused by corrosion remained on the surface of the rudder pedals. The corrosion had already broken through the zinc chromated surface of the aluminium components, leaving them mottled. These worn areas were rough to the touch. We considered whether to leave them as they were or to sand them smoother.
Photo: Jouni Ripatti We decided to sand them so that the corroded spots would be as inconspicuous as possible beneath the new painted surface. The corrosion patches were sanded with a scouring pad, which worked well. The more severely corroded spots had become so rough that they were carefully “carved” smooth with a thin-bladed utility knife. In this way, the corroded areas were made sufficiently smooth for painting. The rudder pedals of BL-106, mottled by corrosion, were now ready for painting. Photos: Lassi Karivalo, unless otherwise mentioned Translation to English: Erja Reinikainen |
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Avainsanat: aviation history, restoration, Tuesday Club, Bristol Blenheim |
Unfastening of the OH-XTM Super Chug propeller and fitting a new oneSunnuntai 7.12.2025 - Tuesday Club member The propeller of the OH-XTM Super Chug (in Finnish Super Sytky), which was damaged in a landing accident and donated to Aviation Museum Society Finland, broke in the crash. A replacement in good condition is required. The wooden propeller on OH-XTM was manufactured in the United States and bears a manufacturing plaque reading “MARFA HEGY TEXAS.” The propeller is stamped with the dimensions 54x44, indicating its diameter and pitch. It is also stamped with the numbers 6-81, which presumably refer to the month and year of manufacture.
Fortunately, we were donated a suitable propeller for the OH-XTM Super Chug’s VW 1600 engine. Antti Laukkanen, restoration manager at the Finnish Aviation Museum, decided to part with a propeller he had for the benefit of our Super Chug’s engine. This propeller was manufactured by E. Pankkonen in the 1970s. Pankkonen produced propellers under official permit, including those for the Fournier RF-5 “Tuulia” aircraft. These were much needed in the 1970s: according to the 1975 damage summary in the Finnish Ilmailu (= Aviation) magazine, the Tuulia in Turku was already using its eleventh propeller in its history!
We were eager to test whether the bolt holes of the donated propeller would fit the propeller hub of the OH-XTM engine. For this reason, the original but damaged propeller, which was still attached to the Super Chug’s VW 1600 engine, needed to be removed.
The disassembly began with the propeller hub cover, i.e. the spinner. Once the numerous crosshead screws at the rear edge of the spinner were removed, the spinner could be pulled off with a bit of prying.
Now the broken propeller could be detached. The propeller hub bolts came loose easily, allowing both the bolts and the propeller's mounting flange to be removed. There was some speculation as to how tightly the propeller would still be stuck to the mating parts of the mounting bolts. However, after tapping the propeller lightly with a rubber mallet, it came off easily.
With the propeller removed, the mounting ring for the spinner’s screws underneath could also be taken off, leaving only the hub with the propeller mounting bolt mating sleeves (threaded inserts) attached. During the disassembly, all screws, bolts and washers were labelled and placed in a plastic bag to await the completion of the Super Chug’s restoration and the installation of the new propeller on the VW 1600 engine.
Once the broken propeller had been removed and the hub was free, the donated propeller was test-fitted to the Super Chug’s engine. The propeller bolt holes in the donated propeller matched perfectly with the threaded inserts in the hub. The new propeller’s holes were, however, slightly smaller in diameter than the mounting bolts. This means that when the propeller is eventually installed on the OH-XTM Super Chug’s engine, its bolt holes will need to be slightly enlarged. Photos: Lassi Karivalo Translation to English: Erja Reinikainen |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, Ressu |
Cleaning and painting the Snoopy?s Continental A 65 engineTiistai 2.12.2025 Ressu, i.e. Snoopy (OH-XEA) was originally equipped with a Continental A 65 engine. However, the original engine has not survived. Nevertheless, we managed to obtain a similar type of engine, from a crashed aircraft, to install in the Snoopy. Although this engine is damaged and unfit for use, it suits our purposes. We are restoring the engine to look like an operational one and supplementing it with missing parts so that it can be mounted on Snoopy’s nose.
All parts still attached to the engine, except for the cylinders, were disassembled. We were unable to detach the cylinders as the pistons were completely seized inside them. The detached parts were cleaned using various methods, including the engine block and its cylinders. For the cylinders, we decided that to paint them properly, including the cooling fins, they would have to be thoroughly cleaned before painting. Therefore, we opted to take the Continental engine block, with the cylinders still attached, for glass bead blasting at Taximo Oy in Tattarisuo, Helsinki.
Photo: Juha Veijalainen
Before sending the engine to be glass bead blasted, it was plugged up to prevent the blasting media from getting inside the engine, even though this engine will never run again. The open intake and exhaust ports were covered with thin aluminium plates. A similar protective cover was made from thin aluminium for the opening left by the removed timing gear cover, to stop blasting material from entering. This was done by placing the removed timing cover on a sheet of aluminium, tracing its shape, and cutting out a piece to match, with holes drilled in the edges for fixing pins.
We mounted the Continental engine onto an engine stand so that it could be rotated easily, much like a spit roast. To install the timing gear cover, the engine had to be removed from the stand. This was done with an engine hoist. Once the protective cover was attached, the engine was returned to its stand. It was deliberately taken for blasting while still mounted, as this made it much easier to rotate during the cleaning process. Our Continental A 65 engine was now ready for glass bead blasting.
Photo: Reijo Siirtola The engine was transported from Puusepäntie to Tattarisuo in a passenger car, where the engine and its stand could be loaded, pulling it in with a cargo strap. A week later, the engine was collected from blasting and, still on the stand, was taken to the Finnish Aviation Museum for painting the cylinders. This was because the museum has a spray-painting tent, which we don’t have at the Puusepäntie workshop. Black and white photographs of the Snoopy show that the engine’s cylinders and valve covers were painted black, while the block was left in aluminium. We followed this original approach as well.
Photo: Juha Veijalainen
Photo: Reijo Siirtola Before painting the cylinders, the block was protected with plastic. The cylinders to be painted were brushed and washed with Sinol to remove any dust left from the blasting. The spark plugs were then removed, and the edges of the plug holes were greased with Vaseline, as they were to be left unpainted. The engine was then taken to the painting tent in the museum’s yard. The cylinders were spray-painted with semi-gloss black Isoguard Pansar paint. Surprisingly, a large amount of paint was required, as the cylinders and their cooling fins had a lot of surface area to cover. The cylinders and cooling fins were painted twice to ensure the spaces between the fins were thoroughly coated.
Photos: Reijo Siirtola
After painting, the Continental engine was transported by car back to the workshop in Puusepäntie. There, the engine block was wiped down with Sinol, after which a clear Isotrol varnish was brushed onto the block’s surface to protect the aluminium from oxidation. Now the Snoopy’s Continental A 65 engine block and cylinders were cleaned and painted. The transformation from the engine’s original condition was remarkable. Photos: Lassi Karivalo, unless otherwise mentioned Translation to English: Erja Reinikainen |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, Ressu |
Painting of the Bristol Blenheim bomber pilot's seatKeskiviikko 26.11.2025 - Tuesday Club member The pilot’s seat of the Bristol Blenheim bomber, which was assembled for the Finnish Air Force after the war and designated BL-106, has been under restoration at the Tuesday Club. This aircraft, which received the BL-106 designation, was assembled in the early 1950s from stored parts of various Blenheim individuals as a V-series aircraft. There is scarcely a single part in this aircraft from the original British-manufactured BL-106, which was flown to Finland in December 1937. The original BL-106 overturned in a forced landing on 8 June 1944 and was damaged beyond repair.
Photo: SA-kuva The restoration of the seat from BL-106, which was assembled after the war, reached the painting phase in early autumn. In preparation for painting, we examined what kind of paint residues could be found on the seat as we cleaned the rusted or otherwise oxidised surfaces of both the seat pan and the seat frame.
After examining the surfaces, we concluded at first that the seat frame’s steel parts had been painted black. However, upon closer inspection, it became apparent that on top of the black paint there had been a layer of grey paint. This was confirmed when brackets, or clamps, were removed from the steel tubes of the seat frame, revealing grey paint underneath. Scraping the grey paint with a fingernail exposed black paint beneath the grey layer. Based on these findings, the decision was made to paint the seat grey.
The same paint was more clearly visible on the surface of the aluminium seat pan, although several different shades of grey and greenish-grey paint could be seen there. It was established that the topmost layer had been grey paint. In addition, a speck of red paint was found at the end of the handle that adjusts the tilt angle of the seat pan.
Bright green paint was also found on the aluminium parts of the control column which is attached to the seat frame. This green paint is a primer, which was used by the State Aircraft Factory. During overhauls at the State Aircraft Factory also the cockpits of Blenheims built in Britain were painted with grey paint in accordance with the VL’s standard, using shade RAL 7005. In the same way, we will paint the pilot’s seat of BL-106. It should be noted that the cockpits of the British-manufactured Blenheim aircraft purchased by Finland were painted with the aircraft grey green shade used by the Royal Air Force (RAF Aircraft Grey Green BS381c-283). Before painting the seat with grey paint, the steel tube frame, which had been cleaned of rust, as well as the steel parts of the aluminium seat pan, were treated with Isotrol lacquer, which is a primer that offers excellent protection against rust. In contrast, the aluminium parts do not require protective lacquer but are painted directly with Isoguard Pansar topcoat paint, which is specifically designed for metal surfaces, using shade grey (RAL 7005).
The seat frame was first treated with Isotrol lacquer. After that, the topcoat painting with Isoguard Pansar paint began with the seat pan. The inside surface of the seat pan was painted first, using brushes. Isoguard Pansar paint has the advantageous property of levelling out very well even when applied with a brush. Once the inside surface of the seat pan had dried, the outer surface was painted. After this, the seat frame was painted.
Once both the seat frame and the seat pan had been painted, the seat frame and the pan were joined together. The pan and the frame are connected to each other by a horizontal connecting tube, resembling a large cotter pin. It consists of two tubes that are pushed against each other and a locking bushing which is slid over their butt joint. On both sides of the seat frame and of the the seat pan, there is an opening aligned for this steel tube. The ends of the connecting tube are pushed through these openings from both sides of the seat, towards each other. Once the ends of the tubes meet, the locking bushing, which is fitted onto one of the tubes, is slid over the butt joint to secure the connection and make it rigid. In this way, the seat frame and the seat pan were joined together. The connecting tube also serves as the axis that enables the adjustment of the seat pan’s tilt angle. The seat itself has its own separate mechanism for adjusting the angle.
Getting the connecting tube with its three parts into place proved to be a challenge. It took some time before the locking bushing, which secures the ends of the tubes, could be locked in place with the bolts running through the connecting tube. We had to enlarge the holes for the connecting bolts using a thin round file before we could push the bolts through the connecting tube. It was also tricky to get the bolts that prevent the connecting tube from moving sideways into place and to tighten the nuts onto their ends.
The restoration of the pilot’s seat for the Blenheim BL-106 has now been completed. Or, in fact, there is still one more task to be done. The leather surface of the grip padding on the right side of the seat is badly worn and partially torn. We are considering whether to restore or conserve this worn seat padding. We are leaning towards conservation, and for this we need an expert, since there is not enough expertise for this in the Tuesday Club. Photos: Lassi Karivalo, unless otherwise mentioned Translation to English: Erja Reinikainen |
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Avainsanat: aviation history, restoration, Tuesday Club, Bristol Blenheim |
The repairs on the Super Chug fuselage under wayKeskiviikko 19.11.2025 - Tuesday Club member The repairs on the Super Chug OH-XTM, which was involved in a serious landing accident, have started. The first target will be the damaged fuselage of the aircraft. The lower part has been damaged between the rear section of the cockpit area and the firewall. The firewall is the rear section of the nose part, covered with a metal plate on the outer surface for fire protection. The lower part of the fuselage has been completely destroyed to the floor level, and the covering plywood on both sides is partly tattered halfway up the fuselage. The rear fuselage remained intact in the crash.
The fuselage between the cockpit and the firewall of the OH-XTM was laid ”inverted” to facilitate repairs. To start the repairs on the wooden fuselage, which had been stripped of the engine, the front section of the fuselage was emptied of all the wires and gadgets. First the fuel tank, which filled the front section of the fuselage, had to be removed to gain access to the wires and tubes leading from the cockpit to the engine bay. The fuel tank fastening straps were opened, after which the tank was lifted out of the front section of the fuselage. The tank straps were left in place for the time being.
After the fuel tank had been removed, the wires and cables going through the firewall from the cockpit to the engine bay were detached from their holders and the wires were pulled through the firewall. To completely empty the front section of the fuselage, we had to detach the rudder pedals, which were attached to the broken front fuselage former, and the wires leading from the pedals to the rudder.
Photo: Jouni Ripatti
When the aircraft hit the ground, the firewall was mostly torn loose from its fuselage joint and simultaneously it was damaged at the edges. It had to be taken out for repairs. The firewall and fuselage joint seam was sawn open, using a multi-tool saw blade, to cut loose the part that was still hanging to the fuselage. Thus the firewall could be detached from the fuselage for repairs and the space between the cockpit and firewall opened, apart from the fuel tank straps.
Photoa: Ari Aho
As to the fuselage side damaged covering plywood sheets, it was established that the repairing would be better done by covering anew the side areas with plywood. Thus the damaged areas of plywood were sawn off with the saw blade of the multi-tool. The plywood was sawn along the fuselage stringers so that about 10 mm of plywood was left outside the edge as a rabbet for the future butt joint. A 20 mm high wooden batten will be glued on the fuselage stringer as a support for the butt joint where the edges of the old and new plywood join. Photos: Lassi Karivalo, unless otherwise mentioned ranslation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club, PIK-21, Super-Sytky, OH-XTM |
The OH-XEA Snoopy fuselage coveringLauantai 8.11.2025 - Tuesday Club member Before the Tuesday Club’s summer break, we had attached the covering fabrics on the Snoopy’s fuselage upper and lower surfaces and on both sides of the cockpit. We couldn’t have covered more at the time because we had run out of the covering fabric we used. However, we had time to start the tightening lacquering on the fuselage upper and lower covering.
The covering of the Snoopy’s sides was started by making a cardboard template of the sides. According to them, pieces of fabric were cut off for the covering of the sides. The pieces of fabric, cut to form, were attached to the frame of the fuselage with contact glue. The fabric was first glued from its upper edge to the frame tube of the fuselage. After this the fabric was glued from its lower edge to the frame tube, stretching it from the hem at the same time. This way the fabric was made tentatively tight to wait for the water tightening and the subsequent tightening with nitrocellulose lacquer.
Photos: Lassi Karivalo Translation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, "Ressu" |
OH-XTM Super Chug fuselage ready for repairsLauantai 18.10.2025 - Tuesday Club member After the Super Chug fuselage had been moved to the Puusepäntie workhop, the preparations to restore the damaged fuselage began. The first task was to detach the engine from the fuselage, because handling the damaged fuselage with the heavy engine in place would be nearly impossible.
Photo: Matti Kainulainen So we started to detach the Super Chug’s VW 1600 engine from the fuselage together with the engine mounting. In doing so we’ll avoid detaching the wires, tubes and engine equipment within the engine mounting frame.
Photo: Jouni Ripatti The engine mounting was attached to the fuselage with five bolts. We tried to open the nuts of the bolts that penetrated the firewall. The bolts, however, turned simultaneously when the nuts were turned. Somehow, we had to gain access to the bolt heads behind the firewall. If the nose of the aircraft were intact, gaining access to the bolts would be almost impossible, because the bolts were situated behind the fuel tank between the cockpit and the firewall. Now, however, the nose of the aircraft was torn because of the crash, so we could reach the bolts and unscrew the nuts.
Photo: Ari Aho
Photo: Antti Hietala At the same time all the wires and cables, connecting the engine through the firewall, were detached. Part of them could be easily detached, but others fought us all the way. When the engine oil had been drained, we were ready to detach the engine.
Photos: Antti Hietala
Photo: Ari Aho The engine was tied with cargo straps to an engine hoist, and the engine was pulled gingerly out of the nose of the Super Chug, hanging from the straps with the engine mounting. The detached engine was lowered on straps to a solid worktop to wait for further action.
The fuselage without the engine was still resting attached to a support frame made of pieces of four by two. Now the fuselage could be detached from the frame. The straps and other devices were opened, and the fuselage was carefully lifted from the supporting frame on to the table. We were a little apprehensive to lift the fuselage, nearly broken in half, but it held on well.
Because the fuselage of the OH-XTM has been damaged in the lower part between the cockpit and the firewall, it would be the most convenient, if the fuselage were to be on its back. So it was decided to place the fuselage on its back on two trestles, to facilitate the restoration work. One trestle would be by the cockpit opening and the other would support the rear fuselage at the stem of the vertical stabilizer.
We pondered what the suitable working height would be to restore the fuselage. It was decided to be 120 cm from the floor level. We adjusted the legs of the trestle by the cockpit so that the Super Chug’s fuselage top line, or in this case the damaged bottom line, would be at the height of 120 cm. The rear fuselage trestle had to be built.
It was built from the dismantled four by two pieces of wood of the Super Chug’s supporting frame. It resembled a normal wing trestle, only it was narrower. The level of the trestle was adjusted with a piece of fire hose used as strap, so that the whole of the fuselage was level and 120 cm from the floor.
After finishing the rear fuselage support trestle, the fuselage of the Super Chug was lifted upside down on the trestles. Thus the fuselage of the OH-XTM is ready for the restoration work. Photos: Lassi Karivalo, unless otherwise mentioned Translation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club, PIK-21, Super-Sytky, OH-XTM |
Restoration of the Bristol Blenheim pilot's seat under wayMaanantai 8.9.2025 - Tuesday Club member Last year we finished the restoration of the co-pilot’s stool from a V-series (BL-106) Bristol Blenheim bomber. Our object was a short-nosed Blenheim, assembled after the war from surplus parts in the 1950’s, having dual controls for training purposes. Beside the pilot’s seat there was a stool-like seat for the copilot. The controls in front of the seat were connected with rods to the captain’s controls. Mind you, that this series V-Blenheim aircraft (BL-106), assembled after the war, has in fact nothing in common with the UK-built war horse (BL-106), which was destroyed in a crash landing on 8.6.1944.
After restoring the copilot’s stool we moved our sights on the pilot’s seat. Restoring is all about cleaning the seat frame, basically a steel tube construction, from dirt, grease and rust. For the part of the seat pan, it meant cleaning the surfaces and sanding before painting. Note that the seat had no back armour. As the first task we detached the leather-covered padding of the seat armrest to be conserved. After that we started the cleaning of the pilot’s seat. Soon we realized that cleaning would be more efficient and easier, if we could separate the aluminium seat pan and the seat frame.
Separating the seat pan and the seat frame necessitated the removing of the steel cross tube, rather like a big split pin, joining them. The cross tube consists of two tubes, joined by a butt joint, and a sleeve around the seam. We finally managed to slide the rusted sleeve from the seam and thus separate the tubes. We stripped the seat frame of all the parts that we could and detached the numerous rusty clips and other fasteners from the frame to be cleaned.
Some of the parts of the pilot’s seat were merely dirty and grimy, so to clean them for instance Fairy Power Spray was used. It removed the grease and dirt reasonably well from the surface of the parts.
The badly rusted tubes of the seat frame were cleaned by using abrasive pads, sanding papers and a steel wire brush attached to a cordless drill. For small parts, like nuts, a steel wire brush attached to a Dremel was used. The small items we detached from the frame were cleaned with an ultrasonic cleaner, which we had obtained.
When rust from the surface of the rusty tubes was removed, in places black paint was revealed. Based on that we concluded that the seat frame of steel tube structure had last been painted black. The cleaning of the tub-like aluminium part of the seat pan, made it apparent that the aluminium surface had been primed with grey primer and finished with greyish green surface coat of paint. The surface paint responds in shade to the greyish green Temalac ML 90 BS 283-shade we had already used in restoring the co-pilot’s seat. As primer we’re going to use Isotrol-lacquer and as surface paint Isoquard Panzer paint. The black paint will be the semigloss Isoquard Panzer paint.
We’ve more or less completed the cleaning the pilot’s seat from rust and grime, so the next phase will be the painting of the seat. Photos: Lassi Karivalo Translation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club, Bristol Blenheim |
Tuesday Club's autumn season at full swingKeskiviikko 3.9.2025 - Tuesday Club member The autumn season, which started halfway through August for the Tuesday Club, has got on a good start. There’s plenty of work to do. Naturally the Snoopy’s (OH-XEA “Ressu”) restoration will continue with the covering of the fuselage as the main object. The fabric is in place on the fuselage, and the tightening lacquer is being applied. The damaged Continental A 65 engine, which we received to be installed to the Snoopy, is being prepared to be cleaned by glass bead blasting.
With the restoration of the Bristol Blenheim bomber pilot’s seat, we’ll carry on from where we got before the summer break. The seat frame and seat pan surfaces are close to being ready for painting.
The Demo-Myrsky is under construction both at Puusepäntie and at the Finnish Aviation Museum. The Demo-Myrsky consists of the Myrsky MY-14 test wing, built during the restoration project of the MY-14, and the MY-5 fuselage frame. With the aid of the Demo -Myrsky, the inside structure of a mixed construction Finnish fighter will be demonstrated. That’s why, for instance, the fuselage frame won’t be fully covered. At the Puusepäntie workshop the repairs on the horizontal stabilizer, rudder and the damaged original elevator are under way. At the Museum the refurbishing and completion of the MY-5 fuselage frame are being worked on.
We’ve had our work cut out with the two sea containers, bought by Aviation Museum Society Finland, and brought at the yard of the Puusepäntie yard. One of the containers will become a working space for fire work and the other one will serve as a storage container. Both the containers have long since seen their heyday, so they will be refurbished on the outside. Holes in the containers will be patched, and the surfaces will be sanded. The outsides will be painted with the blue colour used by the Aviation Museum Society. One already is of a pretty blue colour.
Photo: Reijo Siirtola We’ll start with the fuselage the restoration of the PIK 21 Super Chug (OH-XTM), which was donated to Aviation Museum Society. The fuselage was brought from a storage container at the yard of the Finnish Aviation Museum to Puusepäntie. The engine will be detached from the fuselage before we can commence the restoration of the lower part of the badly damaged and plywood-covered fuselage.
The job list for the autumn season also contains the refurbishment and repairs to the ailerons of the DC-3 “the Seagull” (OH-LCD) situated at the yard of the Finnish Aviation Museum. Both the ailerons’ coverings need renewing and the stem of the right-hand aileron is damaged. The Air Veteran lot will detach the ailerons for us to restore. Photos: Lassi Karivalo, unless otherwise mentioned Translation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club |
Restoration of the Blenheim navigator?s seatKeskiviikko 18.6.2025 - Tuesday Club member We received the Blenheim V-series or “short-nosed” Blenheim’s navigator and pilot seats for restoration at the Tuesday Club.
Both the seat’s steel tubes were badly rusted, but neither seat had suffered significant damages. The navigator’s seat, or rather stool, was significantly more straightforward to restore because of its simple structure and smaller size. It would greatly help restoring the pilot’s seat, if the seat pan could be separated from the seat frame. The aim of the seat restoration is to clean the rust from the surfaces of the supportive tubes and smaller parts, grinding the aluminium surfaces and finally painting them.
We began the restoration with the navigator’s stool. The padding was detached first and the seatbelt as well. The seatbelt was partly torn and needed to see a cobbler. The seat cover of leather has worn out and lost its colour. It needs to be conserved. We will not do it. We examined the round shaped seat plate, bent at the edges, for shades of paint found on the surface. Light green colour was visible, under which darker green could be seen. Thus the surface of the seat plate had lastly been painted with light greenish grey paint and under it there was an older darker green paint.
Paint residue could also be found from the surface of the steel tube stem of the seat. This process was helped when the rusty stems of the seat were treated with Industrial ECO Complex Blue-solution. The solution revealed a green shade of paint on the surfaces of the tubes. In addition, some old pigment or paint chaff was scraped from the surfaces of the rusted tubes of the stem. Some of it was placed under a 600 times magnifying microscope. It turned out that there were three different layers of paint on the tubes of the stem. The lowest was brown, then grey and greenish grey on the surface, in other words the same shade that was found on the surface of the seat plate. In consequence we decided to paint the seat with the similar shade of light greenish grey paint. To start the restoration proper, we detached the aluminium seat plate from the stem. It was fastened to the stem both with bolts and rivets. The bolts were loosened first. After that the rivets attaching a bracket to the edge of the seat in the upper part of the stem were drilled out, after which the seat plate came off the stem.
Then we started to remove the rust from the stem steel tubes. The rust was removed from the tube surfaces, so that a layer of surface paint became visible. The tubes need not be ground to gleaming metal, because we use Isotrol lacquer and paint for the painting. The Isotrol will stop the rusting from spreading, even though rust would have stayed in the rust crevices of the steel tubes. Rust was ground off first with a coarse sanding paper, wiping the dust off at times. We then moved to finer sanding papers, feeling at the same time with fingers whether the surface of the tube was clean and smooth enough. After the coarse surfaces had become smooth and the old paint became visible, the sanding of the steel tubes was complete. We moved on to deal with the seat plate. It was an easier task. The aluminium surfaces of the seat plate were lightly sanded with fine sanding paper. We didn’t indulge in any grinding off of the old paint. The main thing was that loose paint was removed from the seat surface and the aluminium surface became smooth.
After both the steel tube stem and the aluminium seat plate had been ground, they were lacquered with clear Isotrol, which leaves a protecting film on the metal surface. For the surface paint it was necessary to define the shade of the seat colour. We ended up with the grey green Temalac ML 90 BS 283 shade for the seat. With this formula the seat’s Isotrol oil paint was shaded.
Two Comprehensive school students, doing their work experience learning period at the Finnish Aviation Museum, painted the stem and seat plate of the navigator’s seat. Well, at first the quality of the work left something to be desired. However, with careful guidance a good result was achieved. That’s just the purpose of this kind of work experience period, isn’t it?
After the painting it was time to reassemble the seat. The glass bead blasted original assembly bolts were fitted, and the seat stem was riveted to the edge of the seat plate. The rivets were finally painted grey green, to avoid eye sore. We had a cobbler repair the seat belt. The restoration of the navigator seat in the Blenheim bomber was ready. Photos: Lassi Karivalo Translation to English: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club, Bristol Blenheim |
Puusepäntie workshop got an illuminated signKeskiviikko 11.6.2025 - Tuesday Club member There was a wrecked illuminated sign of aluminium construction on the outside wall of the Puusepäntie workshop, rented by Aviation Museum Society, left there by a former tenant.
We dislocated at first the plexiglass plate of the outer cover. the original sticker emblem could be removed from its surface in pieces with a sharp scraper. Finally, the plexiglass surface of the illuminated sign was wiped clean of the sticker glue with Sinol. The aluminium surfaces of the frames of the illuminated sign had been oxidized and tarnished. We gently ground the surfaces clean using both an abrasive pad and very fine sanding paper. The old fluorescent lights were removed and after cleaning the inside of the sign the old lamps were replaced with LED-lights.
On the surface of the opaque plexiglass of the illuminated sign we designed a presentation of our workshop. The upper part of the illuminated sign will show a picture of the Focke-Wulf FW 44 Stieglitz (SZ-18), owned by Aviation Museum Society, with clouds in the background, and the lower part will hold the logo of the society and the text Aviation Museum Society Finland.
We fastened the frame of the outwardly cleaned illuminated sign, equipped with LED-lights, onto the wall of our Puusepäntie workshop, above the opening of the overhead door. We fixed a temporary cardboard plate as the outer cover of the sign to prevent the rain from getting inside.
When the front cover was received from the printing company, with its resplendent picture, the plexiglass was installed, replacing the cardboard one. So the splendid, illuminated sign advertising Aviation Museum Society’s Puusepäntie workhop was ready. The sign is yet be connected to the power supply with a pecu (photo electric control unit, “twilight switch”), so that with the darkening autumn nights it will switch on, advertising the Aviation Museum Society’s workshop. Photos: Lassi Karivalo Translation: Matti Liuskallio |
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Avainsanat: aviation history, restoration, Tuesday Club |
Super Sytky OH-XTM to be restored at Tuesday ClubMaanantai 14.4.2025 - Tuesday Club member Aviation Museum Society has received PIK-21 OH-XTM Super Sytky (in English unofficially “Super Chug”), a damaged experimental aircraft, as a donation. The OH-XTM was designed, built and owned by M.Sc.Eng. Kai Mellén. The aircraft was completed in 1982 and is a single seat Formula-V-racer of wooden construction, with a VW-1600 powerplant. Last summer the aircraft was involved in an air accident, serious enough to damage the fuselage beyond repairing to airworthy condition. In consequence the owner of the Super Chug decided - as an alternative to wrecking it - to donate the entire aeroplane to Aviation Museum Society to be restored at the Tuesday Club. The wings of the Super Chug remained relatively undamaged. The aircraft will not be restored to airworthy status at the Tuesday Club. It will be restored to be a whole, operable display artefact. It’s important that the prototype of the PIK-21 OH-XTM Super Chug, designed and built by Kai Mellén, will remain a display artefact and at the same time an example of the magnificent series of PIK-designed aeroplanes.
On Saturday, 12 April 2025 the delivery of OH-XTM arrived at the yard of the Finnish Aviation Museum. The Super Chug, which had been carefully tied on a trailer, was unloaded. After that the fuselage, supported by a wooden framework, was carried into a sea container for shelter. The wings and other components of the aircraft were also stored in the container.
At the Tuesday Club the restoration of the OH-XTM Super Chug won’t start immediately. We are still in the middle of restoring the OH-XEA Snoopy experimental aircraft at the Puusepäntie workshop. The restoration of OH-XTM Super Chug will commence at some point during this year. Photos by Lassi Karivalo. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, PIK-21, Super-Sytky, OH-XTM |
Restoration of the Snoopy's fuselage continuesTorstai 10.4.2025 - Tuesday Club member The fuselage of the OH-XEA “Snoopy” has been stored at the Finnish Aviation Museum since its restoration was put to hold in December. Now the fuselage has been transferred to the premises rented by the Aviation Museum Society at Puusepäntie in Tuusula, and it is possible to carry on with the restoration work. Although we couldn’t yet fully concentrate on the restoration projects, because the Tuesday Club’s workshop had yet to be fully refurbished. However, we were able to start the restoration work along with finishing the refurbishing of the workshop.
We carried on with restoring the Snoopy with attaching instruments in its empty instrument panel. The lacking instruments have now been installed. The missing instruments could be seen in a photograph of the Snoopy’s instrument panel from 1969. We are grateful to the people at Turku Flying Club, who rustled up most of the instruments in the panel. We also thank the Finnish Aviation Museum for providing us with the rest of the missing instruments.
Kuva: Esko Keskinen In completing the instrument panel, the one instrument giving us the biggest problems was the Russian air speed indicator, because it lacked the mounting ring fastened on the instrument. Well, we managed to install the instrument with a clamp around it. We were able to fasten the instrument with four angle irons under the clamp.
Because we didn’t want to leave empty the opening at the centre of the lower part of the instrument panel, we stuck temporarily a digital thermometer there. That’s to say, we don’t know which instrument there was originally, because that instrument is lacking from the photo at our disposal. Furthermore we put two switches we bought from Motonet into the two empty holes in the instrument panel. They don’t resemble the earlier ones with longer stems in the Snoopy’s instrument panel, but we’ll let them stay there for the time being. Of course, we’ll be trying to find switches like the original ones to be installed into the instrument panel.
Kuva: Jouni Ripatti The Snoopy’s metal fuselage frame was completed for covering at the end of 2024. So, we have started covering the fuselage frame with the vertical stabilizer, which is an integral part of the fuselage frame. We made at first a cardboard template of the stabilizer. Cotton fabric was spread over the template and a piece of fabric, a bit larger than the edges of the cardboard template, was cut off.
The fabric was cut to oversize with intention, to leave adjustment allowance, when cutting the fabric to a tight fit.
All the more, we wanted to check the tightening properties of the fabric we were using. So we attached a piece of fabric with a stapler to a wooden framework and started tightening the fabric with nitrocellulose lacquer. After two layers of 25% lacquer, we spread a layer of 50% nitro lacquer. After applying these layers of lacquer, the fabric began to tighten in a way we’d hoped, i.e. shrink to resemble a drum top. The final tightness will be found out when we’ll get to using the 100% NC Speed nitrocellulose lacquer.
The Snoopy’s fuselage frame came to us without the cockpit plexiglass panes and the windscreen. The new plexiglass panes of the left-hand side of the cockpit and the right-hand side door pane were acquired and cut to form already towards the end of last year. They were made of 3 mm thick polycarbonate plexiglass. A cardboard template was made of the missing cockpit windscreen, and a plexiglass blank will be cut according to the template. The plexiglass sheet will be bent to the right shape by heating, so that both sides of the windscreen nestle tightly to the front sides of the cockpit. So far we haven’t tried this kind of plexiglass shaping by heating, but we are confident of making it a success. Photos by Lassi Karivalo except if otherwise mentioned. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, "Ressu" |
Snoopy's fuselage and engine to PuusepäntieTorstai 27.3.2025 - Tuesday Club member Equipping the Aviation Museum Society’s rented premises at Puusepäntie in Tuusula into the workshop for the Tuesday Club has advanced so well that we decided to move the fuselage and engine of the experimental aircraft Snoopy, stored at the Finnish Aviation Museum, to the new workspace. This means that restoring the Snoopy will continue from the point where we left it at the end of last year. Bringing the Snoopy to Puusepäntie is a kind of milestone in taking the rented workspace into its proper use. Well, the equipping of the Puusepäntie workspace is still not quite finished, but we’ll get there while working on the Snoopy and other restoration projects. Let it be reminded that restoration work at the Finnish Aviation Museum’s restoration workshop came to a close at the end of last year, because the restoration workshop was changed into a space supporting the oncoming move of the Finnish Aviation Museum. The Tuesday Club will participate these Museum operations and continue restoring museum worthy aircraft at the Aviation Museum Society’s rented workshop at Puusepäntie.
Kuva: Jouni Ripatti.
Kuvat: Reijo Siirtola. On Tuesday, 25 March 2025 we gathered at the Museum to transport the Snoopy’s fuselage and engine to our new workshop. The Snoopy’s fuselage and engine, situated in a storage container, were pulled out of the container to the Museum yard. The fuselage was hoisted on to a trailer, where it was carefully fastened with cargo straps. A light tarpaulin was spread on the fuselage to protect it during the trip. The Snoopy’s engine, fastened in its mount could be loaded in a minivan.
Kuva: Jouni Ripatti.
Kuva: Reijo Siirtola. When the loading was ready, we drove the ten or so km from the Museum to the Puusepäntie workshop. There the fuselage and engine were unloaded and pushed into their new home.
Kuva: Reijo Siirtola.
Kuva: Reino Myllymäki. The Snoopy’s restoration will commence at the beginning of April, simultaneously with giving the workshop the finishing touches. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, "Ressu" |
Equipping Tuesday Club's premises at full swingMaanantai 10.3.2025 - Tuesday Club member Aviation Museum Society Finland rented premises at Puusepäntie (Carpenter Road) in Tuusula to secure the continuity of the Tuesday Club’s work. The Club’s restoration operations drew to a close at the Finnish Aviation Museum’s workshop at the end of 2024, because the restoration space was turned into a workshop serving the Museum’s move. The premises at Puusepäntie were rented for three years, or for the period of time during which the new Museum building would be completed. Well, if that wouldn’t realize, we could continue at Puusepäntie, until restoration work could be continued in the workshop in the new Museum.
Photos by Jukka Köresaari
Equipment and work machines brought along from the Finnish Aviation Museum have been hauled for the last couple of weeks to the empty hall at Puusepäntie. We obtained a laudable amount of work machines and equipment from there, thanks to the Finnish Aviation Museum. The items include band saws, face grinders, circular grinders, a column drilling machine, a compressor and an industrial vacuum cleaner.
Photo by Jukka Köresaari Smaller articles have been transported from the Finnish Aviation Museum to Puusepäntie in cars and trailers. To transport big and heavy objects like tables and work machines we luckily had at our disposal a lorry equipped with a rear platform lift. Many of the work machines were manually pushed out of the workshop and on to the lift, but we were assisted in the loading by the Museum’s fork lift.
Simultaneously we have been able to obtain, from a long list of needs, furniture and other equipment to furnish the premises. Fortunately these have been available at a low price or even with no cost. We do still need furniture, such as lockers and shelves, and equipment, e.g. a coffee maker and a medicine cabinet. The premises rented by the Aviation Museum Society isn’t merely the Tuesday Club’s workshop. It will be at the same time a storage for publications by the Aviation Museum Society and Ketterät Kirjat Oy (a publishing company). A space will be therefore reserved separately for these two storages.
When various pieces of equipment have been brought in through the Puusepäntie door, shelves and lockers are being assembled on the walls for restoration material and tools. So far everything looks quite confusing, but day by day the chaos will turn into organization, and beginning restoration activities will be possible.
It will certainly take some time yet to furnish the Puusepäntie workshop. However, we aim to be able to continue restoration work in the new facility of the Tuesday Club at the beginning of April. Then the members will continue work both on the Myrsky Demo Wing and on the restoration of the Snoopy (OH-XEA). Along with these projects also smaller restorations will be done, such as the refurbishing the pilot’s seat of a Bristol Blenheim bomber. Photos by Lassi Karivalo except if otherwise mentioned. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club |
New premises for the Tuesday Club for continuation of restoration workMaanantai 17.2.2025 - Tuesday Club member As was told in the previous blog, restoring aircraft at the Finnish Aviation Museum took a break. Restoration work at the Museum will continue after the new Museum will be completed in approximately three years’ time. For that purpose all the ongoing projects of the Tuesday Club were halted, i.e. stored in sea containers at the Finnish Aviation Museum’s yard. The Aviation Museum Society has every intention to secure the continuation of the restoration work without interruption till the new Museum is ready. That’s why the Aviation Museum Society has been looking for a temporary facility in the Helsinki metropolitan area where the restoration work of museum worthy aircraft by the Tuesday Club could be continued. There are plenty of empty storage space for rent, but for instance around Ring road III, or south of it, the rents are too high for the Museum Society’s economic situation. In looking for temporary premises we aimed at a solution, in which the facility wouldn’t be too far from the Finnish Aviation Museum, because co-operation with the Museum would continue close knit. A few months hard work brought a result at last. The Society decided to rent an empty premise, suitable for our purposes, in Tuusula, not far from the Museum. There’s an open 140 m2 space, suitable to be a workshop. There are two consecutive rooms in addition for storage and social purposes.
The rental contract comes into effect at the beginning of March. Before that the owner will do some maintenance and modifications to enhance the suitability of the space from our point of view. Because the rented property is an empty hall, it must be furnished as a workshop. The last weeks have therefore been spent gathering various equipment and other necessities, to be able to start the restoration work. We have luckily succeeded in obtaining what we need from various sources without cost. We even have succeeded in getting along from the Finnish Aviation Museum necessary equipment, work machines and tools. After the new Tuesday Club workshop has been furnished and adapted to serve the restoration work, the parts of the Snoopy(OH-XEA) and the Demo Myrsky, currently stored in sea containers at the yard of the Finnish Aviation Museum, can be brought to the Tuusula workshop. This way the restoration can be continued. It’s possible that later this year the refurbishing of the PIK-21 Super Sytky (OH-XTM) will start. It’s been damaged in a forced landing. Although the Tuesday Club’s restoration activities will move from the Aviation Museum to the Tuusula workshop, the intense co-operation with the Finnish Aviation Museum will continue. First of all, we’ll continue weekly preparation work for the Museum’s move, under the Museum’s guidance. Secondly, we can nip over to the Museum to use for restoration purposes the fire work container, painting tent or to use machines, like the lathe, which remained in the Museum’s workshop. In this sense it’s excellent that the Tuusula workshop is situated only a ten-minute drive from the Museum. Photo by Reino Myllymäki. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club |
Restoration work took a break at the Finnish Aviation MuseumTorstai 30.1.2025 - Tuesday Club member Restoration operations at the Finnish Aviation Museum were discontinued at the end of 2024. The break will last until the work can be restarted in the new Aviation Museum, which is rising near the present Aviation Museum. It may happen approximately at the end of 2027. The reader can wonder, why the break already now? Moving the Finnish Aviation Museum to new premises is a herculean effort. In principle every artefact in the Museum will be dealt with, assessing whether it will need possible maintenance, repairing, conservation, or restoration measures. If beforementioned measures will be needed, they will be taken and after that it will be decided if the artefact will be placed in the new Museum, or will it be stored in the collection centre? From the beginning of 2025 onwards the Museum’s restoration workshop will primarily become the maintenance, repair, and restoration space for the aircraft and their equipment from the Museum’s exhibition halls. First to be taken under scrutiny will be minor artefacts in the exhibition halls, for example the aero engines. Maintenance work could then advance from primary gliders and advanced sailplanes to small aircraft. They will be disassembled and brought part by part to the restoration workshop for the necessary repairs or restoration operations. For instance, the primary gliders and advanced sailplanes have been hanging from the ceiling for decades, so at least they should need maintenance. But before the previously mentioned check-ups and maintenance work can be started, the restoration workshop must be organized and cleaned and the restoration projects, which have continued till the end of last year, have to be stored somewhere else. So the projects, such as the Valmet Tuuli III, OH-XEA Snoopy and Caudron C.50 restorations and building of the so-called Demo-Myrsky, must be packed with all parts and equipment and stored to wait for better times. We have our work cut out for us in cleaning and organizing the restoration workshop for the new task. Restoration work of aircraft and other museal tasks have really been going on there from the end of the 1980s.
Straight after Epiphany members of the Tuesday Club started, with guidance from the Museum, to clean and organize the restoration workshop and packing restoration projects to be moved to storage. The work has progressed at a good pace. Unnecessary and unusable material for the future projects, such as all kinds of wood and metal debris, have been recycled in large amounts. Part of it has also been disposed of as non-recyclable waste. The premises have also been cleaned and tools and other articles put to their places.
The Tuuli III, Snoopy, Caudron and Demo-Myrsky parts that were in the restoration workshop, have now been wrapped in bubble plastic to be stored. Smaller parts were put in storage boxes. The Tuuli parts were put in a big spacious plywood box.
Before storing the Tuuli III fuselage was protected with Tyvek polyethene fabric, which is breathing in such a way that it lets moisture out, but not inside. The fuselages of the Tuuli III and the Snoopy, Snoopy’s engine and the restored Walter Gemma radial engine in the workshop, used by the Finnish Film industry to create wind, were moved from the restoration workshop to the 45 feet long sea container at the Museum yard, owned by the Finnish Aviation Museum. The transportation went on deftly either by a forklift or in a car tow.
Perhaps we’re already getting the upper hand in organizing the restoration workshop. Still there is cleaning and organizing to be done before we can bring the first aero engines from the exhibition halls to the restoration workshop for inspection and maintenance. Photos by Lassi Karivalo. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club |
The Snoopy got its horizontal stabilizer strutsMaanantai 27.1.2025 - Tuesday Club member The Snoopy horizontal stabilizer has on both sides a metal strut attached to the fuselage. The struts haven’t survived, so they had to be made. We scrutinized photos of the Snoopy. They showed that the struts have been of round metal tube. We found at the metal store of the Finnish Aviation Museum some 10 mm thick aluminium tube, suitable for making the struts.
Photo by Esko Keskinen.
For making the struts their lengths had to be determined. Therefore the Snoopy’s horizontal stabilizer was fastened to the fuselage. It is fastened to the fuselage with three 8 mm thick bolts. They haven’t survived either. So we bought such ones with nuts and washers. Before fastening the stabilizer, the holes for fastening the stabilizer on the fuselage were cleaned with a round file, after which the stabilizer was fastened to place.
Now the strut length from the bracket in the fuselage to the fastening bolt in the stabilizer could be measured. It turned out to be 60 cm.
Two 60,5 cm long pieces were cut off the aluminium tube. The ends of both the tubes were squeezed flat for drilling holes for the fastening bolts. At first the holes for the fastening bolts were drilled to one end of the strut, after which the struts were fastened to the brackets on the fuselage. The flat top end of the strut was placed in line with the fastening bolts in the stabilizer. We saw that the top end of the strut fitted exactly to the bolt.
We marked the place for the fastening bolt to the flat top ends of the struts with a felt pen and holes were drilled accordingly. After that both struts were fastened in place on the stabilizer. It was noticed that the stabilizer was horizontal and steady at its place. So the horizontal stabilizer had received its new struts.
The struts made of aluminium tube were unfastened to be painted. The struts were painted with blue grey Isotrol oil paint. At the same time the elevator operating rod, made of aluminium tube, was painted. After the paint had dried, the struts were once more put to place, after which the stabilizer was unfastened, waiting for the fuselage restoration to be ready. Photos by Lassi Karivalo except if otherwise mentioned. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, "Ressu" |
Refurbishment of the Hansa and Moth modelsPerjantai 24.1.2025 - Tuesday Club member The Karelian Aviation Museum in Lappeenranta, has in its collection wooden models of the I.V.L A. 22 “Hansa” 4F35 (later IL-35) and de Havilland D.H.60 (MO-97) aircraft.
Both types of aircraft were licence built at the Aircraft Factory of The Aviation Force (Later the Air Force) in Suomenlinna. The I.V.L. A.22 aircraft were built on the licence from Hansa Brandenburg W.33 aircraft. Many modifications were made in the aircraft built in Suomenlinna so that the aircraft didn’t fully match the original anymore. However, it has always been simply the Hansa in common language, as in this blog, too. The Hansas served as maritime reconnaissance aircraft in the Finnish Air Force, and the Moth as a trainer and a liaison aircraft. The Hansas were struck off charge in mid 1930s and the Moths after the Continuation War.
Because the wooden models of both the aircraft were in poor condition, the Karelian Aviation Museum queried of the Tuesday Club, whether they could repair and refurbish the models. We were pleased to meet the challenge, because we had earlier on restored for them the tail boom stabilizers of the Mil Mi-8T helicopter and the wings of the Link Trainer. On top of that we have, in our Club, an excellent model builder, who took on the job. In refurbishing both the models we adhered to the principle of fixing or completing what’s broken but otherwise followed the principles of preservative conservation. The aim is to preserve originality, where the models wouldn’t be repainted, but the original paint surfaces will be maintained with preservation. We will respect the original modellers and earlier restorers by leaving as much of the original patina visible as possible, however, avoiding the models looking ragged.
First we took on the Hansa. The Hansa’s swastika emblems drew our attention. They were of paper and had been glued to the wings and fuselage. We decided to remove the ragged paper emblems. They were soaked with water and removed with a painter’s spatula, and under them painted emblems emerged. This left us thinking, why new emblems made of paper had been glued on. Perhaps the previous restorer had thought that the old ones were worn out and glued new ones out of paper on them.
The painted emblems, discovered under layers of paper, were in surprisingly good condition. They were patch-painted only to an extent that they wouldn’t jump out as too fine, compared to the patinated appearance of the rest of the aircraft. A quaint detail was that one of the fuselage swastika emblems was a mirror image. We decided to preserve it as it was. It’s common knowledge that so called reversed swastikas had in fact appeared in the surfaces of Finnish Air Force aircraft. Might this have been the case in the 4F35 individual, the example aircraft to this model?
The Hansa model’s engine cowling was rusted. It was meticulously sanded clean. Then the cowling was bordered with narrow masking tape and painted with silver enamel paint. The radiator cells at the front end of the engine were painted dark and the exhaust tubes penetrating the cowling were painted black. The stepping boards at the junction of the wings and fuselage were loose. They were properly fastened and painted silver. The paint on the wooden surfaces, especially on the upper surfaces, was scaling off. The scaling paint was removed with the masking tape/sticker method, where the loose scales remain on the tape, but the solid paint surface stays untouched. After the tape treatment the surfaces were lightly sanded with fine sanding paper. Finally the surfaces were lacquered with matt acrylic lacquer. It suits this purpose well, because the lacquer won’t change the appearance of the original patinated paint surface but gives it good protection.
Both the pilot’s and observer’s “offices” were tidied by painting them with brown acrylic paint. The painting was brought to the upper rims to emulate the leather paddings.
The model’s propeller was made to resemble a laminated wooden propeller. It was sanded and lacquered with semi matt lacquer. Brass reinforcements were painted to the leading edges of the propellers. Finally, the swastikas that were used in the State Aircraft propellers, were transferred as decals on the propeller blades. The refurbishment of the Hansa was now completed, and it was time for the Moth.
The wooden Moth MO-97 model was refurbished like the Hansa complying the principles of repairing conservation. The Moth had suffered worse than the Hansa with the passing of time. The coupling of the fuselage and the upper and lower wings had failed. The threads emulating the wing stiffeners, or lamellas, were broken off. The Moth’s paper swastika emblems had dried up all crumpled and were unusable.
First, the Moth was dismantled, and the refurbishing was started with the swastika emblems. The wings’ paper emblems were removed by soaking and the swastikas that were painted on the wooden surface, were cleaned with a magic sponge. After that the swastikas that appeared from under them, were carefully completed with blue and white paint. The wing emblems were restored to reasonably good condition in this way. The fuselage emblems were in such sorry state that they were replaced with decal swastikas. Otherwise the fuselage and wing surfaces had kept well, so they were just cleaned and given a protective layer of matt acryl lacquer.
Rigging the Moth was started by joining the lower wings and the fuselage. The coupling of the lower wings and the fuselage were made sturdy by installing metal reinforcements. The struts joining the lower and upper wings were fastened on the lower wings. The middle section of the upper wing, where the fuel tank was situated, was mounted on the fuselage. The upper wings could be joined to the middle wing using their original brackets.
The stiffening threads emulating the struts and lamellas in the Moth model wings had to be replaced with new threads. As thread, twined cotton thread of thickness two was used. The darker, thinner thread was used as wing stiffeners and thicker light thread to reinforce the struts. Attaching the threads was started by drilling holes for them into both the upper and lower wings with a Dremel Mini extremely thin bit. The threads were squeezed through the drilled holes with a needle threader used by dressmakers.
When the end of the thread was passed into its hole, a drop of superglue was applied. When the glue had dried, the other end was passed into the opposite hole (e.g. from the stem of the lower wing to the upper end of the strut). The thread was tightened suitably in its hole and superglue was applied into the hole, keeping the thread tight at the same time. The criterion for the suitable tightness is that when you look from the front, the lower and upper wings stay at the right angle compared to the fuselage. After the glue had dried, we made certain that the thread stayed tight, and we moved on to the next reinforcement thread. Working like this, all the four pairs of reinforcement threads were glued into place. In fitting the reinforcement threads we had to be careful that the reinforcement threads were at the same tightness on both sides of the fuselage. Otherwise, the lower and upper wings won’t set at the right angle, or one individual tread is left too loose. When the reinforcement treads between the lower and upper wings were in place, grids of reinforcement tread were attached to the struts between the lower and upper wings. They were made of the thicker twined cotton thread.
The missing long exhaust tube on the left-hand side of the fuselage was built to the completed model Moth. The exhaust tube was made to look original. It was made from plastic 1:48 aircraft black model sprue, from which a piece as long as the exhaust tube was cut. The piece was heated, and the softened plastic was bent to form. At the end of the exhaust tube an aperture was drilled. The front end of the exhaust tube was glued with superglue to the existing hole in the cylinder block. The middle part was fastened with a metal clip. The tube was painted with black acryl colour so that the front end shows a silver hue due to engine heating.
When the Moth’s wooden propeller had been lacquered, small swastika decals were attached to the propeller blades. Now the MO-95 wooden model repair and conservation was ready.
Both the wooden models of the 1930s aircraft, the Hansa and the Moth, are owned by the Karelian Aviation Museum. The repaired models were now ready to be delivered to Lappeenranta to be put on display. Photos by Matti Kainulainen. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, Scale models |
Installing the control wires in the Snoopy's tailTorstai 2.1.2025 - Tuesday Club member The experimental aircraft Snoopy, under restoration at The Tuesday Club, retains the wires from the rudder pedals to the rudder and tail wheel. Instead, the elevator wires had disappeared. We examined the Snoopy’s fuselage to find out how the elevator wires had run. It transpired that the upper wire is attached to the top end of a rocking lever in the tail. Accordingly, the lower wire is attached to the lower end of the rocking lever. So, how to move the elevator? From the photos taken of the Snoopy we noticed a bar from the tail to the underside of the elevator. The other end of this metal bar has been attached to the lower end of the rocking lever, where there are holders both for the wire and the bar. As the wires tilt the rocking lever from side to side, the metal bar moves back and forth, making the elevator move up and down. At the lower end of the control column the lower elevator wire runs through a pulley in the fuselage and on through a tube in the control column lower end winding around a pulley to the lower end of the control column. Accordingly, the elevator upper wire runs from the rocking lever through a pulley in the fuselage, straight to the lower end of the control column. This way the wire forms a connected wire loop that can be operated from the control column.
Before we started to install the elevator wires, we had to lathe the two missing pulleys in the fuselage that guide the movement of the wires. The bolt holes in the pulley holders were drilled clean, after which the pulleys were installed. Now we could start threading the wires to place.
The wires were tentatively fastened with loops with wire locks to the lower end of the control column and the rocking lever. After it was defined how tight the wires should be, the wire ends were equipped with metal rings or thimbles. The wire was tightened around the thimble and the end of the wire was locked at the stem of the thimble with two pressable wire locks made of aluminium. The thimble headed wires were finally threaded to the holder at the lower part of the control column and the locking loops attached to the rocker lever.
After the elevator wires had been fitted, we constructed the metal rod out of 20 mm metal tube, to move the elevator, and fastened it to lower end of the rocker lever. We further checked the working of the rod by attaching the horizontal stabilizer and elevator to the fuselage of the Snoopy. When we fastened the other end of the rod to the bracket on the lower surface of the elevator, it moved as planned, when pulling and pushing the control column.
A wire connects the rudder pedals both to the rudder and the tail wheel. The wire running towards the tail, forks halfway of the fuselage to wires going to the rudder and the tailwheel. The tailwheel turns simultaneously, when the rudder is turned by the pedals.
We fastened first the right- and left-hand side wire ends to the pedals. After that we attached the ends of the rudder wires, which forked halfway of the fuselage, to the brackets on the lower left-hand and right hand-side corners of the rudder. At the same time we noticed that in front of the rudder, there had been pulleys guiding the wires in the fuselage. All that was left was the holder for the pulleys. The missing pulleys were lathed and attached in place. Thus the rudder wires had been installed.
It was time to install the tailwheel wires. The left-hand side wire had been linked to the tailwheel by a coiled spring. The right-hand side original wire lacked the coiled spring. When we thought about the problem, we found out that both the wires should have the coiled spring for the rudder to function properly.
We studied photos of the Snoopy. It transpired from them that both the rudder wires did have a coiled spring. Why it lacked from the right-hand wire, will remain a mystery.
We carried on pondering. If the tailwheel wires have coiled springs, they must have counter springs in the pedals. This way the wires between the pedals and the rudder could remain tight and the rudder movements transit to the rudder and tailwheel. Small metal rings were found in the fuselage and rudder pedals. So we bought suitable coiled springs and installed them to the rudder pedals.
We also bought coiled springs for both the tailwheel wires. So we decided to renew the left-hand side tailwheel coiled spring, in order for both springs to be identical. Before installing the tailwheel wires, we had cleaned the pulleys for the tailwheel wires to be fastened to the tailwheel coiled spring.
At first the coiled springs on both sides were fastened to the brackets in the tailwheel. After this both the wires were attached to the coiled spring with a ring made to the end of the wire. The ring was locked with two wire locks that were pressed around the wire. We still installed, as had been in the original, a backup wire between the brackets and the ends of the wires. The backup wire was threaded through the coil spring. The wire ensures the function of the tailwheel if the coiled spring breaks loose or breaks. We added a turnbuckle to the left-hand side wire of the tailwheel to adjust the tightness.
Thus we had installed to working order all the Snoopy’s control wires in the tail section. Photos by Lassi Karivalo. Translation to English by Matti Liuskallio. |
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Avainsanat: aviation history, restoration, Tuesday Club, Hietanen HEA-23b, OH-XEA, "Ressu" |
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