We sourced a propeller from a 1960's Beechcraft Travel Air which had been removed from the aircraft several years ago and stored outdoors in a polytunnel ever since. Consequently the propeller was very badly corroded which hugely increased the time required to achieve a mirror finish on the aluminium.
The first job was to dismantle the propeller and strip the remaining paint from the blades.
Internal components were then degreased and cleaned ready for reassembly
In order to cut through the corrosion and get back to 'good' metal an angle grinder was used on the blades with a 60 grit cutting disc. As much as 1/16" was removed in places. The photo below shows a blade after all corrosion was removed.
In order to restore a flat surface without imperfections the blades were then further sanded with an orbital sander working from 80 grit up to 240 grit. From this point on the blades underwent dozens and dozens of hours of hand sanding working through 240, 400, 600, 800 and 1200 grit glass papers to achieve a smooth finish. The blades were then ready for the polishing process.
The blades were first cut with a hard sisal polishing mop and brown tripmax polishing compound to achieve a smooth dull finish. From this point a softer white stitch mop was used with a bluemax compound to bring out the shine in the aluminium. Each blade was then buffed to a mirror finish using a loose fold polishing mop. Vienna lime was used to remove any polishing compound residues and then the blades were topped off with a metal polish. The photo below shows the result of this arduous process.
The next task was to prepare the propeller hub for finishing. The hub was bead blasted to remove the old paint and dirt and was then etch primed to prepare the surface for the final finish.
The chosen finish for the hub was deep candy red paint which involves laying down a metallic silver base coat over which a translucent red lacquer is painted. The hub received 3 coats each of silver base and red candy, topped off with 3 coats of 2 pack lacquer. The pressure dome received 3 coats of gloss black and another 3 coats of lacquer.
The old hub fixings were thrown away and replaced with stainless steel hardware. Finished photos below - a rather pleasing result for hours and hours of work...
