Super Caravelle tow bar restoration completed
Torstai 12.5.2022 - Tuesday Club member
Owned by the Aviation Museum Society and badly rusted, the Super Caravelle towbar was taken in the Tuesday Club for restoration six months ago. For the restoration the bar was dismantled. By March the parts had been cleaned of rust, so the surface treatment of the tow bar, that’s to say painting, could be started.
The towbar is to be painted in original colours of the Finnair era. The main colour has been “Finnair Blue”, but the ends have been painted with yellow high visibility colour. The original hues could be determined by a firm called “Pintaväri” from the paint residue still to be seen on the surface of the steel. The blue was found to be NCS S 6030 B and the yellow RAL 1023. For the paint, Tikkurila Oy manufactured Unica Outdoor furniture paint, was chosen. As the primer, a translucent Isotrol-lacquer was chosen, as it protects the parts from rusting.
Before the surfaces were treated with the primer, they were wiped with Sinol-water solution. After this, the parts of the tow bar received as a primer the translucent Isotrol. After the Isotrol had dried, the surfaces were lightly sanded, vacuum cleaned and wiped again with Sinol-water solution.
First the ends of the tow bar were painted yellow. The length of the high visibility area at the loop end of the tow bar has been 50 cm, and at the connector end 73 cm. The area to be painted was bordered with painter’s tape. The loop headed towing bar was also painted yellow and the nose gear connector at the other end likewise.
When painting with the yellow, it was noticed that the yellow paint covers insufficiently, especially when painted on the dark steel surface which has been painted with translucent Isotrol lacquer. The yellow had to be applied up to five layers, before the result was satisfactory. The inability to cover is an annoying feature of yellow paint. The yellow paint would have covered better, if we’d had the good sense to use light grey Isotrol to prime these parts. On the other hand, when we started to paint the parts of the bar with blue Unica paint, we noticed that the paint had an excellent cover from the first layer on. The covering abilities with the same paint differ greatly depending on the difference of the pigment.
When all the parts of the towing bar had received a new coat of paint, the assembly of the towing bar started. First the wheels were connected to the axle, after which the support arms of the wheels were fixed from the lower ends to the flanges in the wheel axles. The wheels were fastened from their support arms to the two broad flanges. At the same time with assembling the wheels, handlebars were screwed to both ends of the tow bar, to lift or move the tow bar by hand.
Now we were ready to attach the halves of the 4,7 m long bar to each other. They were locked into each other with a collar tightened around the attachment point. At the same time the upper ends of the support arms of the wheels were fastened to the collars on the tow bar.
The camber and caster angles of the wheel support arms were adjusted to make the wheels go straight. A connecting piece was fastened to the aircraft end of the tow bar, from which the bar was connected to the nose gear with a pin. Finally the bolt and nut ends of the support arms of the wheels were painted blue.
The rust covered towbar of the Super Caravelle had been restored in the Tuesday Club to its original livery. The change compared to the rust covered one was remarkable. The towbar will still get an original white Super Caravelle-like logo on its side. Somehow, it’s fitting to this time, that the towbar is in the Ukrainian colours.
Photos: Lassi Karivalo
Translation: Matti Liuskallio.