Kurki landing gear under restoration

Torstai 7.7.2016 - Member of Tuesday Club


Suomeksi

VL K.1 Kurki’s maiden flight started from sea ice near Suomenlinna, south of Helsinki, on 20th of March 1927. Most of trial flights were made with ski under gear but wheels were also tried. Kurki was found to be an inferior airplane and it was stored soon after trial flights the same year.

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Kurki’s landing gear is typical for its time. It has a steel frame and a suspension with braided sandum rubber cords. Our research shows that steel frame had originally a black lacquer finish. Wooden skis show remnants of tar, and also Kurki’s procurement documents mention tar. It is unlikely that tar was used for anything else but for treatment of wooden skis.

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After storage of 89 years, landing gear has suffered lots of damage just like the whole plane. All metal parts are badly rusty, tar has evaporated from skis and sandum rubber cords are broken.

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As the first step, the whole landing gear was removed from Kurki’s fuselage. Then it was dismantled to make restoration of various parts easier. It was decided to clean rusty metal parts by mechanical sanding. We did not aim to reach clean metal surface but to remove most of rust before priming with clear Isotrol Klarlack Grund lacquer.

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This primer is covered with glossy black Isotrol Finish lacquer to get a finish which looks like the original black finish of landing gear’s metal parts. Isotrol system is designed to penetrate rust and form a barrier against further rusting process.

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We honed metal parts manually with sanding paper and also with brushes on pneumatic drill. With good weather this dusty work was done outside in front of our workshop. Also  wooden parts of skis were cleaned similarly for further treatment with tar.

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Honed metal parts were first primed with clear Isotrol Grund. As we had expected, clear lacquer brought out remnants of original black finish on steel pipes.

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When primer had dried, we went on with painting metal parts with black Isotrol Finish. Wooden skis are still waiting to be covered with tar.

Avainsanat: aviation history, restoring, old aircraft, VL Kurki