I heard many years ago that polyurethane is fuel proof. Any body out there have any experience with using it for fuel proofing?

I'm using it to fill the weave in a small patch of Koverall....my dope has dried out and I'm too cheap to buy another bottle for such a small job.

Solvent based polyurethane is fuel proof water based is not. Do not mix with butyrate dope as it will not stick.

I have been using water based Polyurethane for over three years and have found it fuel proof with 15% nitro (which is what I use). I use it to fuelproof engine and tank area and also for glassing. I also have a home built 2-jug fuel carrier finished with it that shows no signs of any problems.

However, I only use Water based Flecto Varathane Diamond Floor Finish. The "catch" might be that it costs about $40.00 per gallon (which will last a very long time). I have also heard that Deft brand water based floor finish also works but I have never tried that.

I have also used it to "clear coat" and it does not yellow. Solvent based will yellow over time - it is a given.

I do know (personal experience here) that MinWax is not acceptable (softens and turns to mush) as does Olympic.

My personal experience.....

Dan