# How to avoid brush marks in polyurethane?



## bues0022 (Sep 30, 2009)

I'm having a rough time with my finish. I put 5 coats of urethane on a Christmas present coffee table. The wood has some curl and wavy grain patterns. I keep getting brush marks and don't know how to avoid them. I'm using a foam brush. Should I use a rag and rub it on? Thin the top coat slightly with mineral spirits before applying? (yes I am sanding between coats) I need to complete this tomorrow morning. Any tips?


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## SouthpawCA (Jul 19, 2009)

This might help … I use this method all the time.


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## toddc (Mar 6, 2007)

I prefer to use a wipe-on poly because it goes on thinner and does not leave the brush marks.

You could sand what you have to smooth it, then thin the poly about 50% and use it as a wipe-on. Using it as a wipe-on applies it in a thinner layer and with it thinner it will also dry faster.

Otherwise I use a good brush for applying (I prefer a china bristle) to lay out a smooth coat. The problem still may remain though so once again I default to the wipe-on. Also the thicker brush applied coat will take longer to dry.

Good luck meeting your deadline, you are at the mercy of your product and it's drying time. Do not change product though and do not push it or you will muck it up. I have learned this lesson the hard way.


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## wmodavis (Aug 28, 2007)

With 5 coats of poly built up you might try wet sanding it to remove those pesky marks.


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## oldworld124 (Mar 2, 2008)

I mostly spray the last coat of poly if using normal poly. I also use wipe-on poly as Todd does.

I also use these pads to apply poly. They will work for the finish coat also.

You can also thin the poly a bit so it will flow better. Keep an eye out for runs.


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## stevenhsieh (Jan 8, 2010)

Get rid of the foam brush, it is crap. You can either thin it down to 50% to Wipe On or buy a high quality brush.


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## toddc (Mar 6, 2007)

I think John Ormsby brings up a good point on the pad. I have used store bought pad applicators with good success.

Most often I use a blue paper shop towel folded into a nice pad for application. It is simple and it works quite well.


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## oldworld124 (Mar 2, 2008)

I realized I forgot to add the link to the type of pads I use.

I cut these into 1/4, 1/3, or 1/2 the size at times so as to conserve pads when coating smaller things. A hack saw with a fine tooth blade cuts quickly. Make sure to put on masking tape on the cut ends to lock the styrofoam beads in place. Otherwise they will get into the finish.

http://paint-and-supplies.hardwarestore.com/47-347-pad-painters/handi-painter-pad-108242.aspx


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## toddc (Mar 6, 2007)

So now we are into the next day.

Did you get it figured out? Let us know.


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## bues0022 (Sep 30, 2009)

Sorry for not posting back. It was a busy day yesterday finishing this project, driving home, starting another that needs to be wrapped today….

This is what I did with the extremely limited supplies (was at my inlaws and not near my own equipment/supplies):

Sanded down the top with some fine grit I found in the basement (it said 4000 on the back, but it felt more like 400) Then I diluted my poly down about 50/50 with mineral spirits, and applied with a small chunk of cloth. The results turned out not 100% perfect, but the imperfections are only ones that I notice because I'm picky and I made it. When I pointed the imperfections out to my wife, she couldn't tell, so I know my mother-in-law (gift recipient) won't notice either.

This salvage turned out good, but I definitely need to do some more research on finishing fur future projects. I know very little besides how to very roughly slap on some poly - that's all I've really done before. Now that the Christmas rush is over, I'll do some reading and be ready for the next project.


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## toddc (Mar 6, 2007)

Good to hear the end result worked out.

I have found out over time that most people do not see the minor imperfections that you have become intimately knowledgable of when you work on a piece.

Learn to just not say anything and nobody will ever know.

Am I being deceitful? No. Just being real.

I don't reach for unrealistic perfection, just excellence. I accept the difference between the two.


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## SnowyRiver (Nov 14, 2008)

Glad you got it worked out Ryan. I agree with Steven, try a good quality brush next time. I have always used a brush and find it works best for me.


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## DaddyZ (Jan 28, 2010)

I use the foam Pads & had luck with putting on a good coat of finish, then take a can with nothing but mineral spirits in it soak your brush then cover the finish with it. when the finish lays back down - No Brush Marks !! I have done several times works each time.


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## fussy (Jan 18, 2010)

Ryan,

I'm glad you got it worked out. You've been in a panick and worked your butt off, and you GOT IT DONE! Now relax and think over all the advice you got, try different methods on scrap to fin what works best for you. They all work, but you will like one better than the rest, and that should be the method you use most of the time. Big thing is it's done, your Mother-in Law is happy, therefore your Wife is happy, so that YOU can be happy; so BE HAPPY! Stay safe.

Steve


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