I keep reading about shellac being susceptible to water and developing white rings, etc. So I did some test pieces in white oak, then set wet coffe mugs on them for a couple days… Nothing happened! The shellac was completely impervious, no discoloration at all.
So, what did I do wrong? 😉 Is this a myth, or does it depend on the wood, or what?
“Everything should be made as simple as possible, but no simpler.” A. Einstein
Replies
Where do you live? What's the relative humidty in your house? Have you tried it with an iced drink? Have you tried it at other seasons of the year? Have you tried simply wetting a glass or cup and setting it on the test surface?
OK, I guess I wasn't as clear about my test procedure as I thought...
I took a piece of white oak scrap, put one or two coats of freshly mixed 2-lb cut dewaxed blonde shellac on it, let it dry overnight, then took it into the house, poured water on it and set a coffee cup in the puddle. Left it like that until middle of the next day. Still wet around and under the mug, but no trace of a ring or any cloudiness in the finish.
I also did the same test with a coat of garnet-lac mixed about 4 months ago, not dewaxed, but with one application of thinned oil-varnish under it. Same result.
I live on the North Coast of CA and the air temp in the house is between 62 and 70 F, RH between 50 and 60%. In the shop the temps were probably about 55 to 60 and the RH closer to 70%.
Now, can anybody please tell me if they have personally experienced "white rings" on a shellac-finished piece? Or is this conventional wisdom that maybe derives from some other finish?"Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
I had a white ring happen on a piece finished with shellac. Turns out that it was really in the paste wax layer over top of the shellac. I cleaned it off with mineral spirits, reapplied the wax, and all was right in the world. My first reaction was that it was the shellac so I wonder how many white rings get blamed on the wrong part of the finish.
"Turns out that it was really in the paste wax layer over top of the shellac."
Ah-HAH! (He shouts, triumphantly)
I, too, wonder now if this whole thing is simply a misunderstanding. My curiosity was aroused when I read that shellac actually has extremely high resistance to moisture (i.e. water vapor), but that liquid water could damage it. That didn't sound quite right, so I tried my little experiment."Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
AlbionWood,
Your not a customer...it only works for customers...never the maker of the piece.
The voice of bitter experience?
Was your shellac dewaxed? Did you leave the glasses on for some time--and as Uncle Dunc said, iced drink glasses that continue to sweat? That said, years ago on another forum a person of some renown in the finishing world (whose name I cannot come up with currently) said that dewaxed shellac was very impervious to water damage.
In my experience, shellac has very good water resistance. If I were making furniture to last 200 years, it would be the only choice I would consider. Not even conversion varnishes are as durable, even though they are harder and more chemical resistant. Plus, shellac is very easy to renew and repair. I just sold six American Chippendale chairs from the 1760's that had been through a fire and had some scorches and heat and water damage. I was able to restore the finish to a condition suitable to its age fairly easily. ANY other finish would have had to be removed completely. I just removed the damaged layers and padded on some Seedlac, and they were just as "good as old."
I have done the same tests as you and got the same results, even after leaving water under a glass cover for as long as a week. Alcoholic drinks are another matter. Since ethanol is a solvent for shellac, the possibility of damage exists, but is easily repairable.
I think the reputation arose bcause people mistook the early nitrocellulose lacquer finishes of the twenties and thirties for shellac. They were VERY susceptible to water damage (I have repaired anough of them to know), and people then didn't know one finish from another, as is also the case with most folks now.
Michael R
Interesting test you did, although I'm not surprised that you didn't see white rings after a few days with only water under the coffee cup. Try it again, only this time rub a little alcohol (gin, vodka, whiskey, whatever) on the base of your cup and leave that on your test board for a few days.
I think you'll see a different result.
Mercury, my question is not "how to damage shellac" (ammonia or alcohol would do that quite well, I'm sure), but "does water really damage shellac" as I have seen alleged in almost every discussion of shellac finishing. My experimental results did not confirm the "conventional wisdom" that says shellac is susceptible to moisture/water damage. In fact it indicated quite the opposite - that shellac may be at least as good as varnish for water resistance. So now I am curious about how the conventional wisdom arose in the first place, and am seeking tales from anyone who has actually caused white rings to appear in a shellac finish."Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
Very good points, and for what it's worth I do agree with you. I guess I should have explained myself a little better in my previous post. I believe that the white rings on shellac theory or "coventional wisdom" as you call it, is not actually caused by water from glasses, but rather residual alcohol that has spilled over the side of the glass and been trapped between the table and glass.
I'm not able to verify that theory from personal experience, hence my suggestion that you repeat the experiment with alcohol instead. I realize that I haven't answered your question, but I'm curious myself and was hoping that you could test the idea. Hope that explains what I meant, and now I'll sit back and listen to other opinions.
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