Best Way to Clean Brushes After Poly

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Forum topic by wilschroter posted 02-20-2019 06:42 PM 486 views 0 times favorited 16 replies Add to Favorites Watch
View wilschroter's profile


56 posts in 823 days

02-20-2019 06:42 PM

I’m using mineral spirits to clean my brushes after I apply Poly but my brushes are hardening anyway.

What’s the best solution to soak my brushes after poly?

16 replies so far

View Bill White's profile

Bill White

5181 posts in 4258 days

#1 posted 02-20-2019 06:46 PM

Clean in progressive steps with mineral spirits to remove finish, then wash in soapy water, dry, wrap, you’re done.

-- [email protected]

View MrUnix's profile


7243 posts in 2496 days

#2 posted 02-20-2019 06:49 PM

And make sure you are using real MS, not that ‘green’ crap that they are trying to push these days – that stuff is useless. Although, I gave up using brushes with poly a long time ago… now I only do wipe-on, so the days of brush strokes, runs and other imperfections are long gone; and disposal simply involves throwing the hardened rag in the trash.

I do use brushes a lot for oil based enamel though, which is sorta similar. Real MS and patience works well, and I have brushes that have been used 100’s of times that are still almost like new.


-- Brad in FL - In Dog I trust... everything else is questionable

View Fred Hargis's profile

Fred Hargis

5372 posts in 2791 days

#3 posted 02-20-2019 06:55 PM

Don’t soak them. I use a 3 jar method and it works really well. Some folks shorten it to a 2 jar method. I have 3 jars (duh!) filled about 1/2 way with MS, labeled #1, 2,and 3. When I’m ready to clean the brush I first wipe it off with a paper towel to get as much finish out as possible. Then it gets put into jar 1. I work the bristles in the MS (wearing nitrile gloves, and my jars have a wide mouth for my hands to get in) for a few minutes, and finish it by swirling the brush in the MS by rolling the handle between the palms of my hands. Squeeze the bristles out when removing the brush from the jar. This step might take 3 minutes +/-. Move the brush over to jar 2 and repeat, with a little less time spent there. The to jar 3, no bristle massage, just a swishing, and squeeze the MS out. Next I do something a lot of folks skip, but I like to use a little lacquer thinner to get as much of the oily MS out; then it’s a good washing with Dawn and warm water. After that, the bristles get wrapped in newspaper to hold their shape which is taped closed with masking tape. Sounds like a lot of work, but it’s really not that bad. When I’m finishing a project, between coats I’ll just rinse the brush with MS and put it in a plastic zipper bag. It keeps easily for 24 hours until the next coat. One last thing, eventually you’ll see a pile of white crude at the bottom of the MS jars….this is the resinous material you inced from the brush. pour off the MS in jar 1, clean it out and return the MS. Take jar 2 and decant what’s needed into jar 1, then clean. Same with jar 3, decant into jar 2. The MS never wears out…just need to get the crude out. Refill jar 3 with fresh MS.

-- Our village hasn't lost it's idiot, he was elected to congress.

View CaptainKlutz's profile


942 posts in 1792 days

#4 posted 02-21-2019 12:25 AM

+1 Use real mineral spirits aka White Spirits.
Stay away from odorless or green varieties. They have alcohol and other useless ‘green’ solvents in them.
If you can’t find real MS, look for Paint Thinner. Some poly will clean up well with Turpentine, or Naphtha.

+1 Need to use 2-3 jar method, + clean out oils with soap+water when done.

+1 Stopped using bristle brushes for poly. Now only use disposable foam brushes, or wiping rags and have less issues with brush marks. Only use bristle brushes for classic oil/alkyd varnish, or marine/spar vanish.

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View bilyo's profile


561 posts in 1400 days

#5 posted 02-21-2019 01:16 AM

Similar to the above only I do a final cleaning with lacquer thinner. As Fred said, don’t throw out your used MS. Just let the crud settle then decant the good part for reuse. You can do the same with lacquer thinner to be used for cleaning purposes. Your brushes that are stiffening up can be soaked in lacquer thinner which will likely clean them up to usable condition. If really bad, you can also soften up the old finish with stripper then clean them as above. Or, throw them away.

View BlueRidgeDog's profile


292 posts in 77 days

#6 posted 02-21-2019 01:59 AM

My method is simple, two cans of MS, “used” and “new”. The used “settles” so the pour is generally clear and good product. I pour from “used” and do a rinse then dump it back into “used”. Then from “new” and do a rinse, then that goes in “used”. dry the brush and move on.

Better still is I try so very very hard not to use the stuff! Or cut it with 50% clean MS and wipe it on or use another finish.

View John Smith's profile

John Smith

1680 posts in 460 days

#7 posted 02-21-2019 12:19 PM

this is the process that I use for my brushes – regardless if they are used
in oil or latex paints and finishes.
Care of Brushes ~ see post #4.



-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

View wilschroter's profile


56 posts in 823 days

#8 posted 02-21-2019 12:24 PM

OK so all things being equal, if I’m working with Poly and brushes there’s a good chance my brushes will get ruined pretty quickly if I’m not super diligent about cleaning.

View John Smith's profile

John Smith

1680 posts in 460 days

#9 posted 02-21-2019 12:34 PM

yes, without diligent cleaning, your brushes will be ruined pretty quickly.
[regardless of what medium you are using and if you are painting a cigar box,
desk or a whole house].
it comes down to the price you pay for your brushes (and rollers) and how much they
mean to you. . . . I buy top quality Wooster and Purdy brushes and take care
of them accordingly.
if you want to use your brushes only a couple of times and discard them,
that is totally up to you.

I am a PAINTER – that is what I do – I paint things. so my brushes are an investment.
not something I take lightly.

but ~ if you do find one of your expensive and favorite brushes in a can of hardened
varnish or paint, it CAN be revived and restored back to almost new condition.
there is no need to throw away a $35.00 brush just because it was neglected to the
point of no further use.



-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

View CWWoodworking's profile


308 posts in 476 days

#10 posted 02-21-2019 12:47 PM

Switch to pre-cat laquer if you can.

When I did this, Woodworking became much more enjoyable. Projects are flawless every single time. 2 coats, done in couple hours instead of days.

When I did use poly, wipe on was my choice of method.

View Robert's profile


3315 posts in 1778 days

#11 posted 02-21-2019 04:54 PM

Acetone ;-)

-- Everything is a prototype thats why its one of a kind!!

View PPK's profile


1310 posts in 1107 days

#12 posted 02-21-2019 06:09 PM

Use disposable foam brushes. No cleanup needed. THat’s what I do most often…

-- Pete

View ChefHDAN's profile


1328 posts in 3147 days

#13 posted 02-21-2019 06:18 PM

All I can add to the above is that these spinner tools for rollers & brushes get the remaining product out of the tool. I’ll go through the cleaning cycle, and then last step is to mount it in/on this and hold it in a trash can below the top lip and spin the bejeezus out if it. Brushes are dry and soft when I pick them up the next time.

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

View Planeman40's profile


1365 posts in 3058 days

#14 posted 02-22-2019 03:45 PM

Being an old codger (78), I learned how to clean brushes from an article in Popular Mechanics in the mid 1950s. I have had brushes that have lasted 50 years or longer.

First of all I try to squeeze out as much paint from the brush as possible by placing it between some paper towels and squeezing it out with my hands. This saves a lot of costly cleaning fluids. Then I use acetone (which cuts almost everything) as an initial cleaner, then a final wash in a “brush cleaner” (from Lowe’s). The brush cleaner has something in it that leaves the brush soft and supple. Then (and this came from Popular Mechanics) a final wash with dish detergent and water to wash out all of the other stuff. This soap and water wash I found out is very important!!! While the brush is still wet with water, shape and “point” the bristles and set it aside to dry. Quite frankly, I often shorten the procedure using only the brush cleaner and the soap and water wash. It is worth the effort and expense to buy good brushes and properly take care of them. They can last forever!

-- Always remember: It is a mathematical certainty that half the people in this country are below average in intelligence!

View John Smith's profile

John Smith

1680 posts in 460 days

#15 posted 02-22-2019 04:52 PM

Planeman – I learned painting and brush care from my parents in the early ‘60s.
I joined the Navy in ‘67, I reported aboard my Destroyer as an able bodied Seaman 1/c
and was assigned to the deck force. when the Bosun’ saw that I had some painting skills,
I was appointed leader of the paint team right away.
and if anyone knows anything about Navy ships, they are ALWAYS
being either chipped or painted constantly. and during a hull inspection, the C.O.
will take out his pocket knife and scrape a spot down to bare metal to check for the
proper metal treatment, application of the correct primer and number of layers of topcoat.
my learning curve came from another Seaman not cleaning his brush and it hardened
up like a rock. the Chief Bosun’ made him wear it around his neck on a rope for a
full week – 24hrs a day. so that sort of drove home the importance of taking care of your tools.
to some people, painting is just another chore to get done and be done with it.
for me, it is an artform and I fully enjoy it as well as learning as much as I can about
the chemistry makeup and what is compatible with what.

Keep your bristles firm !!



-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

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