Can water-base Polyurethane be used as a clear coat on a warbird that has been painted with latex exterior paint?
How fuel proof will it be?
Is there something better to use?

Any and all advice is welcomed.

Mike

Yes, it will work, and I have done it. I also use Krylon clear. Many guys use an auto based paint, but I don;t see the need and expense...but, it all comes down to what you like.

F4u5,
Thanks. One more question. Can it be thined with a little water without loosing much poly. I want to airbrush it on.

It should be thinned enough from the can to spray. you can use alcohol /water to thin it also. I just poured it in the gun and sprayed away. you can even get some of the spray can poly to work well if you are spraying satin finish for a war bird.

Gary is correct. I usually thinned about 5 percent. Does not take much, but just enough to get thru the gun.

F4u5 and Gary,
Thanks for the information. I'm going to try it straight from the can on a test piece first to see how well the gun sprays it. If it doesn’t spray well, I’ll thin it a bit with a little water and alcohol.
This is the first time I am finishing a kit with medium tissue/poly, latex house paint and poly for the top coat.
Thanks again
Mike

I tried the water-based clear (Minwax Polycrylic) as a clearcoat but it softened where raw gas got spilled on it. The oil-based urethanes are more gas-proof but will yellow your colors. What I am doing on my present plane is spraying the majority of it with the water-based stuff and just doing the bottoms of the cowls and nacelles with the oil-based stuff. I think the yellowish, dirty look will look scale around the engine areas.

Jim

A point of clarification if you will. Would love to use clear Poly-C as a top coat, but have read that it is not at all GLO fuel proof. Are the preceding responses appropriate to GAS or GLO? Thanks for the info.

The information I needed to know about waterbase polyurethane is for glow fuel (Power Master 20/20).

I have clearcoated both gas and glo. The poly will not hold up to raw glo, but will handle spent glow fuel (muffler residue) OK

I went out and purchased the Nelson Hobbies Poly Clear Flat w/the additive for glow fuel to put on my Hellcat. I heard from a couple of other builders that this product work pretty well.