I brushed three coats of shellac on some shelving yesterday and this morning found some white cloudy areas on the finish. It was humid yesterday with some rain and I did the finishing in my garage. I remember reading or hearing something about humidity and shellac. Was that the problem? Should I have waited for drier weather? Maybe I didn’t wait long enough between coats (about 2 hours)? Or maybe it was the shellac…can opened in May and no problems then, but not used since?
Anyway, will it have to sanded down to the wood (since each coat of shellac becomes part of the previous coats) or might the cloudy areas be on the surface? Or is there some other remedy?
Thanks for any help or suggestions.
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It sure sounds like moisture-caused blushing to me. If the blushing is on the surface than it's relatively easy to fix. Just ball up a clean cotton rag and dampen it slightly in alcohol. Then swipe it across the shellac in wide arcs. The alcohol will dissolve the very outside layer of shellac and allow it to reform minus the blushing. Be careful not to use too much alcohol or you'll have a mess on your hands. You don't want the rag soaking wet. If the blushing is underneath then you'll probably need to sand it down and redo.
I'm not an expert on shellac at all, and I'll happily defer to someone else here who is more experienced with shellac. I do use a lot of lacquer, though. And it's also famous for blushing problems in the exact same way that shellac is. Although waiting for dryer weather would undoubtedly help to avoid blushing issues... I'm pretty sure that there are some slower evaporating alcohols that can be added which would allow you to finish with shellac in even moist weather. I do much the same thing with lacquer by adding slow "retarding" solvents to the mix.
Someone who is an expert with shellac is Jeff Jewitt. Here's the URL to his website: http://www.homesteadfinishing.com
Regards,
Kevin
Kevin's a pal to refer you over to Jeff's site. I'd like to add, even if you did have to remove all the shellac (which probably will not be the case), you'd not have to sand it all off -- expensive, noisy and a PITA. Coats of shellac can be removed using denatured alcohol.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
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