Repairing the Singer Link cockpit operations simulator door

Suomeksi

At the Tuesday Club, our focus has been on repairing the door of the Singer Link flight simulator. Or perhaps it would be more accurate to call it a cockpit operations simulator, since these old Link Trainers or Singer Links cannot really be compared to modern flight simulators.

This Singer Link cockpit simulator is of the same lineage as the famous Link Trainers. The history of Link Trainers dates back to the late 1920s, when the Link Company began developing and manufacturing simulators.

Link Trainer simulators were wooden constructions with wings made either of plywood or, like actual aircraft wings, covered with fabric. After going through various changes of ownership, the Link Company eventually became part of the Singer Company in 1968. After that, the simulators were renamed Singer Links.

The Singer Link door being repaired at the Tuesday Club comes from a cockpit simulator that was used for pilot training at Malmi Airport and has since been removed from use. The Singer Link was used at Malmi in the 1970s and 1980s. This particular Singer Link device is made of hard plastic. Over the decades, the hard plastic interior surface of the door has become brittle and has started to break into pieces. Our task was to repair the cracked interior surface of the door and to polish the cloudy plexiglass window in the door.

We unscrewed the aluminium plate covering the inside surface of the door. Underneath, we found that the hard plastic interior of the door, including the lower edge of the window, was almost completely shattered. At first, we thought about gluing together the cracked pieces in the middle area of the door’s inner surface, but they turned out to be so fragile that we abandoned the idea. Instead, we decided to remove the brittle hard plastic pieces from the middle area of the door’s inner surface, since this area is completely covered by the aluminium plate. Only the damaged areas visible outside the aluminium plate would be patched. For this, we chose to use two-component Souda Metal Plastik Standard polyester filler.

We mixed the two-component filler according to the instructions to achieve a uniform consistency. We joined and filled the broken pieces in place with the filler and used it to patch all the visible gaps. Once the polyester filler had dried, the filled areas were sanded smooth in preparation for painting. The rough sanding was done with a chisel blade, and the finish was smoothed with sandpaper.

The repaired and smoothly filled areas were primed with light grey Isotrol paint. The intention is to paint the repaired spots later with the turquoise colour of the Singer Link’s hard plastic.

There were apparently dried adhesive residues left by masking tape on the outer surface of the door frame. These glue residues were removed using xylene as a solvent. Since the plexiglass window in the door had become cloudy, it was decided—rather than replacing the plexiglass—to try and clean and polish it until clear.

For polishing, we purchased Headlight Lens Repair & Reviver polish, intended for cleaning car headlight lenses. We used the polishing pads supplied with the polish, as well as a soft fabric buffing wheel attached to a screwdriver. After the polishing, the plexiglass was reasonably transparent and shiny. Some cloudy areas still remained. Polishing will continue after the Tuesday Club’s Christmas break in January, possibly by trying a different plexiglass polish.

Photos: Lassi Karivalo

Translation to English: Erja Reinikainen