Re: Wipe on Poly?

[George]

Absolutely enough, if it pleases your eye. Purpose is really to keep the wood from picking up oils and dirt. One coat might reject enough, in reality. Four coats can become a full slick finish.

If you have true poplar, the above is a "plus two" proposition. First and second coats will almost completely disappear.

"Varnish" is generic - resin, oil, solvent mix. Polyurethane is one of many "resins," some naturally occurring, some not, used to make varnish.

I'am making three sets of small bookcase like shelves for my wifes > classroom. Woking with Poplar to mach what they had made several years ago. > Would not have been my first choice. Anyway They want a natural look so > I'm just going to seal them. I was wondering how the wipe on poly is? If I > put on two coats will it be a durable finish, or shoudl I brush on a few > coats? And forgive my ignorance here, I'm a newbe to woodworking, what is > the difference from say Poly and Varish? Thansk for the help in advance. I > love this news group! >

[James "Cubby" Culbertson]

I found Wipe On Poly from Minwax goes on very thin. Will take several thin coats to get any build up. I personally don't use poly very often so this is an observation of mine based on little info.

If you are at all interested in doing woodworking and foresee additional finishing in your future, I might recommend either Flexner's book or one of Jeff Jewitt's. Very nice to have on the shelf when deciding on finishes.

Hope that helps. Cheers, cc

[BillW]

If you use wipe on pole it takes about four coats to equal one coat of brush on. You can make your own wipe on poly much cheaper by mixing regular poly

50/50 with mineral spirits. That is all the wipe on poly is. For the shelves to be durable you will need 6 to 9 coats of wipe on. Put three coats of wipe on an hour apart, let dry over night and sand lightly. Put on three more , etc. Poplar is soft and you will need a good surface film for durability. Look at kitchen cabinets with poplar or pine face frames. After a couple years they are lined with fingernail gouges. For shelves I would brush on at least three coats of poly.... Bill

[Mike G]

Varnish - a carrier, usually mineral spirits, and oil, hopefully Tung, and cross linking resins, synthetic now, used to be things like rosin, amber, etc.all cooked together so it polymerizes when cured.

Poly is a varnish with resins that form a stronger cross link then the ones found in regular test. This makes it more resistant to damage which is both a plus and a minus..

Never used a gel varnish of any type but I'd have to guess that an equal build of gel or brush on varnish is going to provide pretty much equal levels of protection.

[Dr. Rev. Chuck, M.D. P.A.]

Like a high gloss oil finish, but much tougher, with zero maintenance.

Commercial wipe-on poly is about 4x overpriced. Thin straight poly 50% with mineral spirits. Apply like Watco. Scuff between coats, because fresh and cured coats won't burn together.

"Polyurethane varnish" is usually standard alkyd varnish with a few percent of urethane plastic resin added for toughness. Reserve for surfaces that need the added toughness, since it feels vaguely plastic to the touch.

[McQualude]

Ben spaketh...

I will only add a few thoughts... I use Olympic oil based varnish and thin as necessary with mineral spirits (you don't need to thin at all, but thinning may help in hot weather or if you want a very smooth, thin finish). Wait about 8 hours between coats and lightly sand to smooth the finish and give it some tooth for the next coat to grab. Sand the first coat with 220, using a little mineral spirits for lubrication, it will help prevent the sandpaper from clogging. Sand subsequent coats with 400 and final coat with 0000 steel wool. Sand each coat just until smooth, be careful of the edges. Number of coats will depend on how much you thin, when you think you're finished, you probably are. Enjoy.

[Rico]

It seems like thinning it will help it penetrate a bit deeper on the first coat. That should be a good thing. Any thoughts on that?

Rico

[Dr. Rev. Chuck, M.D. P.A.]

Gray ScotchBrite pad slapped onto a random orbit sander.

[McQualude]

Rico spaketh...

Really I don't think it matters, the difference may be a few thousands of an inch difference. The varnish is going to build a tough film quickly and it is the film that will protect the wood.

I put a light, thinned first coat on first because the first coat will be the roughest and you're going to sand it the most aggressively. Subsequent coats will be much smoother.