# Tiny bubbles on water based poly



## TOPO (Sep 6, 2011)

Hi mates, being based in Spain, is difficult to use the same brands of finishes that you are using to I will skip brand names here, and they won´t make sense 
Issue I have is happening with three different brands of water based poly. All of them are quite thick, kind of almost gel consistency, but they flow very well when used. the problem I have is that when applying them, even with the lightests of my brush strokes, or with a foam pad, I´m getting very tiny bubbles all over the place. If I overbrush with only the tip, very slow and faintly, I get rid of some of them, but the remaining will be perceived when totally dry. A quick rub with fine sandpaper, solve the touch issue, but the bubble shapes remain as tiny circles on the wood. That is not a big problem in heavy figured woods, but on clear dark ones, they show as a shore thumb when the light strikes skewed.
Have you find this problem before? I tried with good quality synthetic and natural brushes, foam pads and even with cloth, but I always had the same issue. The cans were not shaken but stirred, and I avoided to discharge the brush against the lid, as some googling suggested… I´m running out of ideas.. could the that is too thick/liquid?

Any suggestions is more than welcome, I prefer to test 20 different solution than fry my brain thinking in what I´m doing badly….

Many thanks in advance, and regards from Spain!

Luis S.


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## pintodeluxe (Sep 12, 2010)

Stirring the poly instead of shaking it may help.
I think the only way to get rid of bubbles is to spray a finish like lacquer, or perhaps try a thinner wipe-on poly.


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## CharlieM1958 (Nov 7, 2006)

Try rubbing out the surface with automotive polishing compound. If the bubble remnants are just on the surface, that might get rid of them.

Also, as Willie said, stir gently rather than shake. And you could always try thinning it a bit to give the bubbles more time to surface and level themselves before the finish dries.


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## RussellAP (Feb 21, 2012)

I'd experiment with some thinner which will let it smooth out on it's own rather than modify the application process.


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## crank49 (Apr 7, 2010)

You have done everything I would have done. Different brushes, foam pad, cloth, etc.
You state that you stir lightly and do not shake.
All this is good.

Only two ideas I have left and one of them has already been suggested; thin the poly.

The other is unconventional for wood working, but a process I bring from jewelry manufacturing experience. You can literally pull the bubbles from the poly while it is in the can with a vacuum pump.
A high vacuum, greater than 28.5" (725mm) WC, will cause the tiny bubbles to expand and float up to the surface and pop. Normally about 2 minutes will do the trick. Note, this must be done in a vacuum tank or other pressure vessel, not the can directly. It would be crushed. I have used an old pressure cooker my wife no longer uses.


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## BillWhite (Jul 23, 2007)

No foam brushes period. No shaking either, just stir. A product in the states called FLOETROL is a "retarder" that really helps WB products flow out without bubbles. Made by Akzo Nobel Paints LLC. 
I use a synthetic bristle "finishing" brush.
Maybe this will help.
Bill


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## Loren (May 30, 2008)

Generally poly comes too think in the can to brush really well.

You might experiment with padding on the finish like shellac.


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## LeeBarker (Aug 6, 2010)

I agree you're on the right track. Stirring is good, not scraping the brush is good.

When you say "quality brush" are you including the Gramercy brush?

I discuss my recent discovery of this tool here.

Also are you straining your product with this kind of seive? It's a very good habit to use these every time.

Kindly,

Lee


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## Dal300 (Aug 4, 2011)

Just my way….

I use foam I've cut from a piece of tractor cab insulation, closed cell, black, heavy.

I use a hot knife to cut it so I get clean, even slices.

I wet the foam, squeeze it and let it sit on an angle for 20 minutes or so before using it.

Not knowing the characteristics of the WB poly you are using, it's difficult to say what is wrong.

The WB poly I've been using is Rustoleum and Minwax. Look up the properties of each and see how they differ from what you are using.


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## 33706 (Mar 5, 2008)

I'm just glad that Charlie M did not burst into song, ala Don Ho.


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## CharlieM1958 (Nov 7, 2006)

I had to think about that one for a minute before it sunk in, Poopie.


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## TOPO (Sep 6, 2011)

Hey! many thanks for the answers… I will try to reply all of them 

Gramercy tools in Spain are a dream to get :-( I will be travelling to Seattle in June, so maybe I can get them shipped there, will love to test something that looks so finely made.

Never heard about floetrol, but will try to find it here!

The pressure vessel, well looks really interesting to perform…

And straining the fluid was not tried before, so maybe I will look around for those filters here…

The thinning process, looks promising, and easier to try, I will try it and keep you posted!

Thanks a lot for all the answers, I really appreciate the willinges of everybody to help here…

Best regards!

Luis


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## RussellAP (Feb 21, 2012)

I would think that straining it would produce more bubbles.


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## LeeBarker (Aug 6, 2010)

It doesn't seem to, but next time I'll watch closely. The strainers I use, purchased from an auto body supply shop, are extremely fine.

Kindly,

Lee


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## RussellAP (Feb 21, 2012)

Does anybody else have Dean Martin singing Tiny Bubbles stuck in their head?


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## Philzoel (Dec 26, 2011)

I used to have bubbles. None any more. Clean surface really well after sanding. Mineral spirits works great.

Why do you use water based? It does not yellow, but it does not hold up well and is not water proof.


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## Charlie5791 (Feb 21, 2012)

Blow on it with a heat gun (carefully) or even a hair dryer. The warmth will pop the bubbles. Done. I'm guessing a hair dryer is more readily available. The heat gun would be major overkill and would have to be used carefully. You don't need to heat them much, but you DO have to do this immediately while the poly is wet and before it starts to skin.


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## JoeLyddon (Apr 22, 2007)

Sounds like your stock is just TOO THICK…

If it's supposed to be brushed or wiped ON, I'd say thin it a little with some distilled water.
Bubbles in thick liquids get "trapped" in them and have to float to the surface to pop… with thick stuff, that might be a problem… Using the heat gun, is a good idea… that's what is used with thick Epoxy fluids…

Is your stuff OLD? Maybe some water has evaporated making it thicker than normal?

Let us know what makes it work… OK?


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## TOPO (Sep 6, 2011)

yeah! looking at the bottom of the cans seems that they were manufactured 3 years ago, so maybe the stuff is too thick, looks like kind of jelly.
I will try thinning with distilled water and the hair dryer trick. Won´t be able to try it up to this weekend, but I will keep you all posted…
Answering Philzoel, the smell of solvents is way to heavy for my wife´s taste, and she is scared about the fire hazard… so, water will be! 

Thanks all!!!


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## Earlextech (Jan 13, 2011)

Once again Bill White has it right and Charlie makes a good point about warming the finish with a heat source. I would only modify that and say put the can of finish in a pot of hot water for 15 minutes before application. Directly warming the fluid before it's applied should remove more of the bubbles.
Gramercy brush is worth the $


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## TOPO (Sep 6, 2011)

Hi folks… two weeks later I will let you know the results of the investigation.

Everything can be summarized in:

you pay 7 euros a can of varnish, you get crappy bubbling liquid
you pay 17 euros a can of varnish, you get a pleasure to extend mixture, no bubbles, no runs, easy to apply and with the right thickness…..

with the 7 euros version, I tried a taklon brush, foam, wipe on, thining, heating it with a heat gun, strain it through 125 and 190 micron filters… an nothing prevented the bubbles to appear. So I gave up and decided to buy something better… turned out to be the right decission, the expensive one work like a dream even using an elcheapo brush.

So, now I have two cans of cheap water poly that will be used as sealer, and a nice one that will do the final coats…

for your reference the brand to avoid is "promade" and the one working great is "V33" floor water based poly version.

Many many thanks for your suggestions and support.. just this time the old saying of you get what you paid for, was totally true! 

Regards from Spain!

Luis


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## TOPO (Sep 6, 2011)

forgot to mention, that one of my mates brought me a set of gramercy brushes for water based varnish from NY… eager to use them! I will let you know my toughts when done 

BR

Luis S.


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