shd3920

I am covering my Kadet Mark II with Koverall and dope, I am completing the final coat of color butyrate and would like to know:
How necessary is it to do a final coat of clear butyrate? Will it be OK with just the coats of color?

I am asking cause I do not have any in stock and would prefer not to spend the extra cash if it is really not necessary.

GAP-RCU

If you're using electric power - no problem, just leave it as is.

If glow... technically, you could get away without clear coats, but the finish won't be as durable. Be sure to wipe away the exhaust and oil ASAP right after flying. Several clear coats, on the other hand, will cost you next to nothing in weight and will definitely give a longer lasting finish. No matter what, clean up any raw fuel spill immediately if you're using greater than 5% nitro.

Good luck, Gary

shd3920

Gonna be powered with a GMS2000 .32
Is that enough power for this trainer with a doped finish?

Phlip

I've rarely used clear coats over colored butyrate dope, and I've never had a problem. Occasionally I see a little color come off on the rag when I clean up, but I've never had a problem on the plane.

Phil

shd3920

Is there a product (possibly Minwax water-based Polyurethane) that is as good as butyrate clear dope as a top coat that will not fade or distort the color dope? Some product that can be gotten at Carr Hardware?

And what paint is safe to use on cowls?

Phlip

Regular Rustoleum spray paint is the best "hardware store" variety paint I've found. It takes a while to dry, but it levels out nicely and is quite fuel proof. Search Rustoleum paint on RCU and you'll find all kinds of threads and opinions and questions on it.

I haven't used or seen any reports on anything clear that truly compares with clear dope, though.

Phil

Hossfly

IMO, the clear topcoats are very much needed to protect the finish. I prefer to use a mix of color and clear for a couple coats then a couple clear coats. I strongly suggest a cure period of two weeks before subjecting the finish to any glow-fuel, especially if you had to use any significant amount of retarder to prevent blush.
What brand of Buty. did you use? My first choice is Brodak which is a formulated version of Randolph. To best of my knowledge, SIG is just repackaged Randolph. Super Flite just never seemed to stand up to glow fuel unless aged for a month or more.

On aged, cured dope finishes, I believe that it is best to NOT wipe off spills too quickly. Let the nitro have a few minutes to evaporate and the chances of no marks/no blush-like dulls seem to be better.
I would be very careful before applying any other finish over butyrate dope.
Just my experiences.

rlmcnii

My Feedback: (3)

Minwax water-based polyurethane is not fuel proof. Tried some on an oak break-in stand and learned this from first-hand experience.