# Spar Urethane clean up



## JamesTinKS (Nov 15, 2012)

I made some tall Adirondack chairs and a table from Menards cedar boards. Finished them with spar urethane. They turned out great and I am happy with the finish. But, I could not get the urethane out of the brush. I used lacquer thinner and it did not seem to do anything at all. What should I have used? I am in Kansas so can get pretty much any chemical.


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## Steve Neul (Sep 2, 2011)

If you let the urethane dry before you tried to clean the brush you might as well throw the brush away. Lacquer thinner will cut it but takes days of soaking. Then from time to time it would help to clean the brush with a power washer. All the soaking and washing then makes the brush fuzzy. It helps some to wrap it with shrink wrap to dry but it's never good as new. Brushes are getting cheaper while solvents are getting really expensive so you have to ask yourself is it worth cleaning.


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## Quickstep (Apr 10, 2012)

The usual solvent for oil based varnishes is mineral spirits or Naphtha.


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## epicfail48 (Mar 27, 2014)

And thats why you dont buy good brushes for applying urethane; youll never get it out of the bristles. Best to just buy the cheap foam brushes, urethane is pretty forgiving in how you apply it, least the oil based stuff is

Oh, and always check the cleanup instructions for finishes, the people who make it know their stuff and guessing wont help at all. Lacquer thinner thins lacquer, not urethane. Different types of finishes have solvents that work for them, and generally they arent interchangeable. Lacquer thinner wont do much of anything to urethanes, mineral spirits wont do anything to shellac, alcohol wont melt lacquer. Oil-based finishes like urethanes get mineral spirits for thinning and cleanup, can also use turpentine or one of the -enes (toluene, xylene, etc).


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## Steve Neul (Sep 2, 2011)

You can clean urethane out of brushes with mineral spirits or lacquer thinner. It's just if you wait until some of it dries on the brush mineral spirits won't touch it. It would take a solvent as strong as lacquer thinner to do the job. If a person is short of time a brush can be tightly wrapped in a plastic grocery sack and washed the next day. We often do this when working at a job site. Don't want to have to wash brushes late in the evening when we get home from a job and just do it the next morning. Wrapped in plastic the varnish just thickens a little at best.


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## _Ogre (Feb 1, 2013)

i'm in the cheap throw away brush club
i buy ebay foam or harbor fright chip brushes by the case


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## redeared (Feb 7, 2019)

I do a double cleaning on a good brush with mineral spirits and they are good for a long time, I gave up on the foam ones long ago, especially the cheap ones from HF


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