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leehaven
08-12-2011, 05:30 PM
Just purchased a Yak 52 with a fiberglass covered wood propeller (Russian 2-blade V-530 propeller). It has a few small pieces of the glass chipping away and a 2 inch long 1/16-1/32 deep fine strip missing on the trailing edge. Although some oil has saturated the exposed wood, it looks very repairable with simply epoxy. I plan to MEK the open wounds and then use a 2 part epoxy to fill and file smooth.

Does anyone know a specification for the maximum repairable defect size? EAA video recommends nothing deeper than 1/8th inch. Anything more definitive?

Is epoxy the ideal repair material for a fiberglass over wood blade?

Any additional preparation techniques better than MEK?

Thanks!

jb92563
08-30-2011, 09:53 AM
Wood is very tolerant of nicks like that, and it is likely the integrity of the prop is fine if the nick is very shallow.

However getting anything to stick properly will be very important. You have to get the oil off first using Mek and clean rags .

For such a shallow and small wound I would use some low viscosity Cyanoacrylate glue and baking soda as the filler to
build up the scratch and allow penetration of the glue in to all the voids and into the wood.

If you must use epoxy, use a good hard sandable epoxy, not your typical Home Depot variety that remains a bit rubbery, is
hard to sand and has crumby adhesion properties. The Cyano is a good alternative and commonly used by many for wood and composite
prop nick repairs.

For the Cyano, apply liberally and saturate the wood and adjoining area, then sprinkle the baking soda on top of the wet Cyano.
You can mound the baking soda into the wound and apply cyano on top and saturate the baking soda adding more as required
to fill the wound. Then after a couple hours you can sand flush and you will have a good repair, paint is optional.

Ray