Varnish

[Pearson]

I clicked on the AC Spruce website to order some varnish for my project. They show a Stits Epoxy Varnish and a PolyFiber Urethane varnish. The Stits Epoxy Varnish has a catalyst listed with it that you have to buy separately. The PolyFiber Urethane stuff doesn't show, or list, any type of catalyst or hardner. I have never heard of a urethane that doesn't require a hardner.

Are these basically the same material? The PolyFiber stuff is a lot cheaper, but if you have to buy a catalyst it will add to the price. The last time I recovered an airplane it belonged to another guy who had never done it before. He bought the materials, and I don't remember what we used. Any thoughts on which of these two products I should order? What are you guys using on your projects? Anyone have any experience with either of the two products I mentioned?

[Robert Lees]

Re: Varnish

Richard,

Use a two-pack varnish ( I think Stits and Poly-Fiber (sic) are the same product). The Urethane varnish is the base; you need to get the catylist to make it do its stuff.

Do NOT get Randolph "Spar Varnish"...it is not two-pack. It is crap.

Now why am I going on about two-pack varnish?

Poly-Fiber Poly Tack fabric cement (which is the same as the "New Super Seam") will remove single-pack varnish like your Mother used to clean your dirty face as a child. A swift rub with an abrasive cloth and you're back to bare basics.

But of course you need Poly-Tack (or Super-Seam) to attach your fabric (Unless you're using someone else's system).

So use a two-pack varnish on wood. (...and incidentally, a two-pack primer on steel and aluminium for the same reason...)

Richard, I got my two-pack spar varnish from the local boating community...it's the same stuff, but cheaper.


I've used all the Poly-Fiber products and been very happy with them.

[N96337]

Re: Varnish

Richard, use the epoxy varnish. I have samples that are still flexible after almost 20 years. Flexibility=toughness and that is what you want.
The single part urethane varnish is not as "hardy" if you will. It's like the single part urethane finishes. It's still a urethane base, but doesn't have the toughness that a catylized urethane will have.
John