# Best Way To Apply Poly



## Olympus (Jan 21, 2009)

I'm really stumped on the best way to apply polyurethane. I do very small projects that are completely flat, no curves or dips or anything like that. I normally use a foam brush but it leaves little bubbles and eventually the tip of the brush starts crumbling away. Is there a better way to apply poly without having a lot of bubbles so I don't have to sand as much between coats? What should I use?


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## bradnailer (Nov 11, 2008)

If I'm looking for a poly finish with some build, I brush on a couple of coats with a high quality brush made for oils. After a fine sanding, I then rub on several coats of thinned poly. The result is a smooth finish with no brush marks or bubbles.


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## jerry (Nov 1, 2006)

The best way to apply poly ?. Don't use another type of vernish.

Jerry


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## CivilEngineer13 (Aug 29, 2008)

If you are getting air bubbles that may mean a couple of things. One, the drying temperature is too high, not allowing the bubbles to come out before the poly dries. Or two, the type of poly (which is a whole other topic) you are using is too thick. Add thinner at about 10-15% (ignore manufacurers warnings if there are any. That is on there to comply will VOC laws) so the bubbles have more time to escape (adding thinner will in no way change the final appearance). If you are still having problems, just add more thinner and try lowering the temp if possible.

Additionally there is no way to eliminate bubbles all together when applying; no matter what type of brush or special techniques you use. the only solution to getting a bubble free finish is as previously mentioned.


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## Olympus (Jan 21, 2009)

I don't think that the temp is too high. It's probably in the low 40s in my garage. And the bubbles appear instantly when apply with a foam brush. I may try the thinner trick though.


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## Terry Beeson (May 29, 2008)

Maybe a dumb question to ask, but don't be offended... are you shaking the poly before using or stirring?


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## Olympus (Jan 21, 2009)

No shaking or stirring.


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## breakfastchef (Jan 14, 2008)

Foam brushes for poly are my brushes of choice. Yes, there will be some bubbles, more with some wood than others, but they work themselves out over a 2-4 hour period. After the second coat and a light sanding, you should be putting poly over poly with minimal bubbles. Aside from forum member suggestions about shaking, temperature and humidity, remember to make very light finishing strokes in one direction, with the grain, for the length of the piece, if possible.


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## Conner (Sep 14, 2008)

I apply with a foam brush and if I can see any bubbles I give a quick puff of air to pop most of them. You can honestly blow out most of the visible bubbles and the finish will largely self-level after that. Needless to say pieces should be laid flat to dry.


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## Olympus (Jan 21, 2009)

I tried thinning down a little with some laquer thinner and it worked great. I will probably have to do a few more coats, but I'm pleased with the results.


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## bzbatl (Feb 10, 2009)

Everyone tells me 4 light coats is better than 2 heavy coats.

I'm finishing a piece in my garage, which is probably around 40 degrees, as well. I only get bubbles where the brush starts or ends, and I just go over it lightly so you can see slight streaks. The poly levels out, though.

Another trick is making sure you don't open and close the garage door too much while it's drying - you don't want to stir up dust.


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## Just Bill (Dec 29, 2008)

Spay cans, perfect finish every time(almost). For small jobs. For big jobs, HVLP gun.


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## rg05 (Jan 6, 2009)

I used a foam brush and it seemed to work pretty well but a friend said he uses just a piece of like an old cotton shirt and i tried it and like the way it works. I'm pretty new at it all so maybe I don't know what i'm talking about or don't have enough experience for a good opinion but so far its been good. Also, in between coats I've been using steel wool to lightly sand the coats.


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## tomtees (Jul 29, 2011)

*So many possibilities!*

 I came here looking for the best way to apply polyurethane to 41 doors and drawer fronts. I've done it several times in the past (call me an experienced amateur), but have always had less-than-great results. What I learned here is that I should spray it, roll it, brush it, and/or wipe it on, but thin it first. 

Using a brush, straight out of the can, I have always had trouble with drips and runs. The helpful advice that I found here that is working for me is to first thin the polyurethane, then use a brush to get into the inside corners and to dab some product onto large spaces. Then, I use a piece of T-shirt to wipe it (with the grain). This puts a thin coat on the piece, and reduces the chance of excess poly going over the edge. 

I shouldn't need the brush to get into the corners on subsequent coats. It will probably take me more time to do the additional coats, but the overall time should be less, since I won't have to do extra sanding to get rid of drips that harden. So far, I've only done one coat on one side of the doors, but it sure looks like this will be the best method for me. It's a bit messy, once the poly soaks the chunk of T-shirt, so I keep a clean rag nearby to wipe the goo off my fingers before moving pieces of wood.

Thanks for the ideas.


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## jack warner (Oct 15, 2010)

spraying by far.


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## cabinetman (Jul 5, 2007)

tomtees said:


> I came here looking for the best way to apply polyurethane to 41 doors and drawer fronts.


 





 
Using a thinned version and wiping on is the best method, IMO. It's very difficult to spray and there is the tendency to apply too much. Unless you get terribly lucky or have a lot of experience with spraying finishes I would stay away from spraying. 

Using a brush can give you the brush stroke problem, and a foam brush will deliver bubbles.












 







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## jack warner (Oct 15, 2010)

and wipping can leave streaks. poly is not that hard to spray. its just thicker than most. but i agree with having exp with spraying.
i have spraying poly down to a science, so its easy for me to say spray it.


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## cabinetman (Jul 5, 2007)

jack warner said:


> and wipping can leave streaks.


Thinned with light applications, and some overlap...I don't get any streaks.












 







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## jack warner (Oct 15, 2010)

i think i would use a danish oil b4 turning a poly into a wipe.


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## cabinetman (Jul 5, 2007)

jack warner said:


> i think i would use a danish oil b4 turning a poly into a wipe.


They are basically the same thing, as far as consistency.












 







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## jack warner (Oct 15, 2010)

i like the old school varnish for the natural resins used. poly's use synthetic resins and in my exp tend to muddy up the finish a bit. specially at thicker builds. but you are correct that most of todays poly's and varnishes are very similar. thats why i make my own varnishes so i can control the oil to resin mix for a particular type of finish.


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## stevenh (Oct 9, 2009)

It would not matter if you don't stir or do stir, do shake or dont shake.

When your put your brush down, it will create a turbine that creates bubbles.

couple of ways of reducing it

-Use a quality brush
-When finish brushing the entire surface, use your brush tip and tip off the bubbles.
-Thinning it down will help brushing it
-Apply light coats


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## ACP (Jan 24, 2009)

I know this is an older post but I'll chime in anyways since its still ongoing. I have had real good luck lately with water based poly. I use shellac as a base barrier coat and brush on the water based poly and am getting good results. It's easy to brush and dries pretty quickly with good results for me. I don't have spray capability so this is my go to "tough" finish.


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## Curly54 (Jul 30, 2011)

I just finished repairing an old cedar chest that's about 80-90 years old I'm guessing and I used polyurethane. It's been a while since I dabbled with wood but now have several projects. It seems as the the poly has gotten a little watered down over the years. I put five coats on sanding in between each one. I used a very good foam brush and it didn't come apart, I found the secret was to have long strokes from one end to the other and when it's entirely coated I just let the brush go from one end to the other with no pressure. I have no bubbles at all. One thing I did do that was told to me by an old timer and it seemed to work. After the last coat I took wax and buffed it with a buffer and it looks like glass and as smooth.


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