Cleaning Up Latex Paint
Tips for getting a latex paint drip off a polyurethane finished surface. August 30, 2005
Any ideas on removing white latex flat paint from a satin finished polyurethane dark stained oak finish?
(Furniture Making Forum)
Try using Goofoff. You can find it at any good paint or hardware store. Test in an out-of-the-way place first.
You didn't say if you're dealing with spatter, spill, or a silly painter. In any case, I've always found that very hot water in a sponge would soften latex and the difference in thermal expansion rates releases any molecular bond that may have formed. Rubber gloves and a plastic scraper.
That's right about Goof-Off. Another alternative you may already have on hand is lacquer thinner.
My wife, a professional painter, uses rubbing alcohol and a terry cloth to remove latex paint (hardened or not) from just about everything. Should not hurt the poly finish.
The most reliable method is to use Goof-off 2. It's different from standard Goof-off. Goof-off 2 is an ammonia based solvent which softens the latex without touching the oil based poly. Windex seems to have a similar property, but a little more mild. Use a clean rag and rotate often as to not rub the softened latex into any open pores of the oak.
I recommend Simple Green. I had 54 cherry wall lamps (sconces) that had paint spatter. My finish was a Waterbased poly. The Simple Green took off the spatter very nicely and hardly touched the finish.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor M:
I have drops of latex semi-gloss enamel on my oak stairs that have been stained with oil-based stain but water-based polyurethane. I tried Goof Off 2 and rubbing alcohol, and neither really worked. They softened the latex just a little bit, and seemed to affect the finish.