Try Varathane Polycrylic

Was at Lowe's the other day and found a gallon of Varathane Diamond Wood Finish. Bar code is 26748 23003. Two unthinned coats brushed out completely filled some soft 1/16 in. It may not be quite as hard a Min Wax. After drying a couple of days it appears to be fuel proof. I poured raw fuel(10%) on and let it sit until dry. The finish showed no signs of staining or softening. While the fuel was on it and wet it did feel a bit soft, but that went away when it dried.

Have to see how it does as a clear coat over some popular paints. Would be nice to have an easy to apply clear coat with no fumes or diisocyanates.

LAST EDITED ON Apr-22-04 AT 05:50 PM (CDT)
 
Phil,

Also see about compatability (as over coat or undercoat) with dope, auto urethane, and maybe, what, Rustoleum?

What about comparable weight?

I don't know about this particular stuff, but the original varathane had a slight amber cast when applied over white.

Phil, I have been experimenting with polycrylic and now use it as base coat with .02 oz. carbon fiber on all wood surfaces and as a top coat. Poly crylic is not unlike any other finish inasmuch as it has to cure. Minwax ploycrylic won't be fuel resistant for a few days after application as a top coat. However after a couple weeks it seems to do a pretty good job. After all, nothing is "fuel proof"; just fuel resistant.

Sunshine

Strangely enough, we used to spray clear Varathane from cans on our inspection jump boots when I was in the Army. It saved time from regular shining but cracked quite easily. I think it might not be the best thing over open bays covered with silkspan. I had considered it as a possible airplane finish way back then, but figured it would be to heavy.

I'm interested in your results Phil! Tell me more.

LAST EDITED ON Apr-23-04 AT 09:21 AM (CDT)
 
all the polycrylic varnishes I've tried appear to be very similar.
Off bluish white opaque solution, dries quickly to a clear film. They all appear to be pretty compatible with other finishes. Brodak dope will go over them. As Brad W. showed, the car finishes go over just fine. They don't have much solvent in them, other than water and alcohols, so they don't do anything to any finish you put them over(at least as far as I remember)

This Varathane(Diamond Clear Wood Finish) apparently uses some different resins in it. They call it Interpenetrating Polymer Network, which probably means they have some polyurethane resin and/or epoxy resin in it to make it more solvent resistant.

I've had major problems with MinWax Polycrylic and Olympia NOT being even remotely fuel proof. I used MinWax to patch a sand through on the tail, and that spot got sticky just from exhaust residue coating it lightly.

As far as weight goes, as far as I can tell it makes precious little difference what the coating is. When you get a solid, glossy film the weights are very similar. Dope may take 10 coats where the PC products take 3. I have a friend who has a plane with a killer dope finish on it- 16 coats of clear over who knows how many coats of color. Just gorgeous, but the finish weighs about 12 oz. extra. No matter what you use, take the time to sand thoroughly and the weight will be in an acceptable range. It may be 9 ounces for PC and 8 for dope, but that is hardly going to kill a plane or the finish.

The Varathane appears to be substantially fuel proof. So is Carver Tripp polycrylic, but that has disappeared locally.

I did try MinWax on silkspan over open bays. I wouldn't recommend it. The new silkspans don't shrink all that well. the water in the varnish made each coat relax the covering until it dried thoroughly. The final result is OK, but dope looks better and is much easier to sand over open bays.