I am finishing my hardwood floors tonight with an oil-based polyurethane. I bought a natural bristle paintbrush and a metal pan, as well as some KleanStrip paint thinner that is "made with Mineral Spirits".

At the end of the poly job I'd like to use the paint thinner to clean both the brush and the pan to make them reusable for future projects. What's the proper/best way? How much thinner do you use? How long does it take to work?

I guess I'm worried that if I use too much or just simply "dunk" the paintbrush in the thinner and leave it too long that I'll ruin my tools.

3 Answers 3


When I use oil based products I use disposable pan liners so cleanup means let it dry-up and throw it away. To clean brushes I use a brush spinner to remove as much material as possible. I swish the brush in a container of mineral spirits and brush a piece of dry cardboard to get out some more of the urethane. Finally I soak the brush for a couple of days in a covered glass jar that has just enough mineral spirits to cover the bristles. After everything is clean I set the mineral spirits filled container in the sun uncovered until it evaporates. I would not dump it on the ground! If you cannot find a way to dispose of it contact your municipal public works dept. Most cities have an annual hazardous waste drop-off.

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    Mineral spirits can be reused many times. Pour the used spirits through a coffee filter into a clean jar and save for next time.
    – Gunner
    Commented Oct 2, 2012 at 1:24

Is it a really good brush? If not, let it dry out, throw it away and use another.

It seems wasteful. But you have to weigh the environmental and convenience costs in using significant amounts of cleaner/thinner, and the other waste generated in cleaning a brush.

I do recognize that a very good brush may give better finishes and be a joy forever, but it is hard to justify the process unless you are a professional doing it every day and having a set-up to handle the cleaning and the caustic waste.

On the other hand, cleaning a really good brush with latex based paints often does justify the cleanup process, largely because the waste is basicly water and can go down the drain.


If it says "made with Mineral Spirits" its safe to dispose of however. This means its made from all-natural minerals; I usually just dump it out on the lawn to get it away from the house.

Edit - please do not dump onto lawn or onto ground, as there are in deed aquifers above the bedrock layer that can absorb the Arsenic that KleanStrip contains and pool them into drinking water supplies.

Instead, pour them directly down the sink, taking care not to splash and get any on your skin.

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    Sure fire way to kill your grass and contaminate any ground water!
    – Gunner
    Commented Oct 2, 2012 at 1:13
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    Hmm, lets read the MSDS for KleanStrip paint thinner - apps.risd.edu/envirohealth_msds/Klean-StripPaintThinner.pdf would you want that anywhere near ground water?
    – Gunner
    Commented Oct 2, 2012 at 1:30
  • 1
    Soil retention blocks all? Are you kidding me? Ever hear of water tables? Osmosis? Commented Oct 2, 2012 at 16:34
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    Lets be absolutely clear here. Mineral Spirits are HAZARDOUS WASTE. Just cause they're made from "all natural" minerals doesn't make them safe. Arsenic is "all natural". Commented Oct 2, 2012 at 16:37
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    Dump them down the sink?! I wish I could downvote this again!
    – Matthew
    Commented Oct 17, 2012 at 2:42

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