Spar varnish isn't particularly waterproof. It has a higher oil content so it is more flexible than regular varnish (though not as hard) so that it can better deal with the wood movement due to humidity variations. It also has UV inhibitors for outdoor use.
I'm not sure that it has any real advantages for indoor use.
Chris
My goodness! Whatta canna worms!
However, the discussion has been very useful. From the links you provided and the information in the posts, I have deduced a few deductions:
1) Shellac may be a good water vapor barrier, but not a good liquid water barrier when in contact with liquid water, such as condensed shower steam.2) Shellac is not flexible, hence is vulnerable to repeated expansion/ contraction cycles, and this is just what one would expect in the bathroom doors, with repeated humid/dry, cold/warm cycles. Maybe my finish was developing microcracks and allowing water beneath the finish.
3) nailshooter41 guessed right, although I didn't "use Zinsser (or similar) products off the shelf", I am "not a full time finisher, because" I DID "mix dewaxed shellac just to use in a bathroom". Dewaxed orange shellac, purchased from Mr. Paddy Olguin, 2-lb cut in denatured alcohol, three coats. Took fer-f****n- ever, but it sure looks nice (except for the doors, of course).4) Recoating with shellac, although probably pretty easy, is probably not the best thing to do.
SO, I will recoat the affected areas (2 big doors, 2 medicine chest doors, and various trim) with some kind of varnish, but not spar varnish. I would prefer to use a less toxic varnish, and I know that the technology has improved markedly in the past few years, as we have a water-based floor finish that has held up extremely well on our red oak floors. Any suggestions on finishes?
LMAO. I like the constructive nature of this thread. Everyone is civil, and a lot of good information has been brought to light by different folks.
I stand corrected. And I hope you understand my comment was not meant to offend by any means. Many "non pro" guys turn out great finishes because they take the time to do all the steps where a pro (ahem..) might be inclined to skip one if possible.
Paddy!? Recently? I thought he retired completely to start another venture and to play with his grandkids. Do you have a recent link or phone number?
Next time you make a batch up, put the mix in a container with the top barely screwed on and put the container in a warm water bath. You will take days off the dissolution. Remember that homebrew shellac has a relatively short shelf life after mixing with alcohol, but will last forever as flakes.
Ahhh.. but it is. Now shellac will shine for you if you let it. Sand off the rough spots on your doors and coat them with the Zinsser "sanding sealer" which is a dewaxed shellac. This will resolvate into the existing shellac finish making ti stronger, and provide a bondable film for your next coating. It will help you negate the effects of the floating nasties that bathrooms have on surfaces such as hair spray, spray deodorant, air fresheners, candle soot from those nasty potpourri smelling candles, etc.
Then apply your new finish coat.
There is no point to spar in the bathroom. Doubtful your conditions are actually THAT extreme.
Do not make the mistake of thinking that water based finishes aren't just as toxic as the solvent based choices. Just because they have water in them makes them sound benign, but they use ammonias, formaldehydes, and other nasty things as their solvents.
If you will search around you will find that almost without exception these days it is accepted that ALL dried finishes are quite low in toxicity, and at that, you would have to ingest them for harm to be done.
I personally think the finish will come down to personal preference. Brush guys have their favorites, and spray guys have theirs as well.
Still, for a bathroom, as others here have said, I would use polyurethane. My choice would NOT be water based poly (I would rather breathe fumes from solvent than ammonia) but solvent based stuff. Most are pretty good, and they all go on about the same so I wouldn't spend a lot of time finding on particular brand. Benjamin Moore makes a good one, as does Sherwin Williams.
At the big boxes you can get the Flecto products which are quite good. Even good old Deft makes a nice one called Defthane.
All of them spray, brush and pad well.
Others will have their thoughts as well, and may be able to get you exactly what you want.
As always, just my 0.02.
Robert
And Watco has a wiping poly that's worked well for me.
I splattered some shellac on my glasses last weekend. It has not come off in the shower after 4 days of washing it.
Tonight I tried soaking in a glass of beer. It still hasn't come off. I guess next I'll have to move up to the vodka.
So, at the very least, I'd say it's pretty waterproof.
Just for clarity sake - shellac *is* a type of varnish. Quoting from woodweb:
"Non-convertible coatings do not go through a change when they dry and can be re-dissolved by their original solvent. Shellac, cellulose and thermoplastic acrylic are such materials.
Convertible coatings go through a chemical change (get converted) and are no longer soluble in their original solvent.
With> Shellac
Back when I was selling a metric ton of shellac per month, one of my most loyal and interesting clients were those making wooden whitewater canoes. They would buy only the finest Kusmi buttonlac (somewhat of a contradiction in terms, as buttonlac is minimally processed, and contains wax, bug parts, bush parts, etc.) to apply to the outsides of the hull. They did this for three reasons:
It was the *only* stuff they would buy. Buttonlac is processed by heat (wrapped in burlap and then heated over a fire until molten), not solvent, and so it is polymerized. Advanced users would either separate it in a centrifuge (in solution), or double-wrap a wad of buttonlac in some commercial filters, submerge in alcohol, and then wait a few weeks for the precious finish to seep out.
That would be me. All the stuff I sold was filtered, not bleached, and thus the ability to retain most of the water resistance properties it originally had.
Someone else mentioned that shellac isn't flexible. I've had the opposite experience. One of my favorite parlor tricks was to take a client's business card (at the beginning of lunch, say), dip it into a handy jar of orange shellac, and then at the end of lunch, bend the card into a circle without the then-dry finish cracking. It loses flexibility after perhaps 100 years or so... don't we all?
Paddyo
p.s. There are a few people that are distributing the same product I used to. shellacshack.com is one of them. I did receive some free samples from the guy when he was looking for verification of his product, but other than that, no affiliation. It ain't as cheap as I used to sell it, but a durned sight cheaper than most I'd say.
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