# Spraying High Gloss Polycrylic drys with micro-bubbles



## gsmarvel (Oct 17, 2013)

I have attempted to spray a fourth coat of Minwax's Polycrylic after allowing the previous coat to dry for a week. This is the third try on putting on a final coat. Each time, the finish goes on wet and levels out perfectly. About 30-60 minutes later after it dries, it develops very small bubbles which affect the glossy sheen. The surface feels smooth and flat but the tiny micro bubbles in the finish make the it lose it's sheen.

After each try, I let the finish cure and sand it back using 220 grit before attempting another coat. I have tried putting the finish on a little thicker, but that did not work. Not sure what is causing this issue. I did not have this issues with the previous coats. This is being sprayed with a Fuji Mini Mate 3 (1.3mm tip) at a temperature of around 60 degrees F. Under the existing three coats of polycrylic are two coats of primer and two coats of an exterior flat latex paint.

Please let me know if you have any ideas on what may be causing this issue.


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## InstantSiv (Jan 12, 2014)

Are they bubbles or does it look like little pin pricks?

Bubbles: Make sure not to shake or vigorously stir the stuff because it will cause the bubbles.

Pin pricks: I get this issue from time to time. I have yet to understand what causes this issue. I've boiled it down to cold, humidity, too thick of an application, and/or surface is not totally clean.


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## conifur (Apr 1, 2015)

Contact the manufacture and ask them there thoughts, sometimes the source has the best answers.


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## JAAune (Jan 22, 2012)

While I'm sure the issues could be solved, I wasn't impressed with Polycrylic and would recommend switching to a different water-based finish. Sherwin Williams makes Kem Aqua Plus and the Varathane diamond floor finish works fairly well.


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## dhazelton (Feb 11, 2012)

I have to ask - you're up to eight coats of finish. Why not use a gloss or semigloss paint next time? The more layers you put on the more chances for trouble to raise it's head.


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## gsmarvel (Oct 17, 2013)

They look like pin pricks embedded in the finish. You can only see them when looking at the surface with a light source. I had thought it might be related to the cooler temperature so I tried to let them dry in a warmer area. That did not help.



> Are they bubbles or does it look like little pin pricks?
> 
> Bubbles: Make sure not to shake or vigorously stir the stuff because it will cause the bubbles.
> 
> ...


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## gsmarvel (Oct 17, 2013)

I have used Kem Aqua Plus before and I like it. Next time I will not use Polycrylic.



> While I m sure the issues could be solved, I wasn t impressed with Polycrylic and would recommend switching to a different water-based finish. Sherwin Williams makes Kem Aqua Plus and the Varathane diamond floor finish works fairly well.
> 
> - JAAune


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## ScottM (Jul 10, 2012)

I had the same issue with the Minwax a while back. I'm new to spraying and figured it was just my technique. It was one of those "I'm probably the only one who will notice" things but I still find it…. Glad to hear about this happening to others. Not glad about the result, mind you. Well, you know what I mean. I may visit my local Sherwin store and see if they carry the Kem Aqua and give that a try. Let us know how the Kem works for you.


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## Mahdeew (Jul 24, 2013)

I had this issue last week with lacquer (must be the weather). Ended up sanding to bare wood and applying very, very thin coats (maximum 4).


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## gsmarvel (Oct 17, 2013)

I contacted Minwax's product support but they were unable to provide me with any information on what may be causing the issue. They also checked to see if the product's batch number had any reported issues, and there were none. They did offer to reimburse me for the cost of the product if I sent them my receipt so at least I don't have to pay for the product that I keep sanding off.

I will give it one more go with a very thin coat to see if that helps.


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## gsmarvel (Oct 17, 2013)

Scott,

I had sprayed the Kem Aqua Plus before and it went on easy and dried quickly. I wish I had started this project using that coating.



> I had the same issue with the Minwax a while back. I m new to spraying and figured it was just my technique. It was one of those "I m probably the only one who will notice" things but I still find it…. Glad to hear about this happening to others. Not glad about the result, mind you. Well, you know what I mean. I may visit my local Sherwin store and see if they carry the Kem Aqua and give that a try. Let us know how the Kem works for you.
> 
> - ScottM


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## ScottM (Jul 10, 2012)

I apologize for subject change but was trying to find more info on Kem products. The SW site lists it as a "sealer". I also found other references to it as a water based lacquer. Others talk about using sealers and topcoats, etc. Finishing terms get me confused.

So is this lacquer or poly (like minwax)? 
Do you use it as a topcoat over stain or bare wood?


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## WoodNSawdust (Mar 7, 2015)

Other more knowledgeable persons will jump in here, but I thought that Lacquer always referred to a hydrocarbon based finish. Maybe water based finish producers are hijacking the term lacquer?


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## ScottM (Jul 10, 2012)

There are lots of products advertised as water based lacquers. All the favorites; General Finishes, Target, ect.


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## JAAune (Jan 22, 2012)

Straight from the company's website:

Kem Aqua Plus

... and archived at WoodWeb.

Product Documentation



> SHER-WOOD® KEM Aqua® Plus is a high quality, water reducible, self-seal clear for finishing furniture, cabinets, and a wide variety of wood and novelty items. It contains a UV absorber to significantly reduce natural wood discoloration due to sunlight. It meets the test requirements of the KCMA as a self-seal system.


It's not a lacquer (no water-reducible finishes are true lacquers). It's similar to poly finishes though I believe the resin of choice is acrylic. I'd have to look up the MSDS to know for sure. Companies call their products "lacquer" to indicate that it's supposed to be a suitable replacement.

You probably saw the Kem Aqua Primer and Kem Aqua Pigmented Lacquer products which are completely different. The documentation specifically says not to use them with the Plus product.

I tried Kem Aqua Plus and liked it as far as water-reducible finishes go but prefer lacquer and conversion varnish. A real lacquer can be repaired at any time and conversion varnish is unbeatable for durability unless a person goes with the 2-part polyurethanes or UV-cured finishes.


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## JackDuren (Oct 10, 2015)

> I have attempted to spray a fourth coat of Minwax s Polycrylic after allowing the previous coat to dry for a week. This is the third try on putting on a final coat. Each time, the finish goes on wet and levels out perfectly. About 30-60 minutes later after it dries, it develops very small bubbles which affect the glossy sheen. The surface feels smooth and flat but the tiny micro bubbles in the finish make the it lose it s sheen.
> 
> After each try, I let the finish cure and sand it back using 220 grit before attempting another coat. I have tried putting the finish on a little thicker, but that did not work. Not sure what is causing this issue. I did not have this issues with the previous coats. This is being sprayed with a Fuji Mini Mate 3 (1.3mm tip) at a temperature of around 60 degrees F. Under the existing three coats of polycrylic are two coats of primer and two coats of an exterior flat latex paint.
> 
> ...


I tried the Miniwax polycrylic one time on a rec room door. Finish went on great but hazes too quickly. After a few attempts I gave up, hung the door and never used it again. I'm a pre-cat or spray oil poly man from there on….

In this case you might try something else on top of this to finish it.


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## Jarrett (Apr 25, 2015)

I had bad luck with it as well, especially as temperature dropped, even though I was still in manufacturer's range. Hot summer days and nights I didn't have as much trouble. Since the bad finish, I have changed brands and finishes all together and am much more satisfied that I'm giving the customer a superior finish,


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## gsmarvel (Oct 17, 2013)

Thanks everyone for the feedback. After a fifth try, I am a beaten man. I contacted Minwax and they cold not give me any reason for the "gassing" effect. I also believe the issue is related to colder temperatures. I had brushed this finish on before successfully, but it was much warmer in the shop by about 10 degrees. I tried everything I could think of to get a last good coat on. Even tried brushing it on the old fashion way in varying thicknesses. Nothing worked. This will be the last time I use this product.


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## firefighterontheside (Apr 26, 2013)

I know minwax gets a bad rap sometimes, but I have good luck with it. I like the polycrylic. It gives me a good looking finish, especially since I exclusively use satin finish. It dries quickly, which allows me to often get three coats sprayed on a project in a day. Is there any chance there's an issue with how far you are holding the sprayer from the surface, holding it too far away gives the product a chance to dry partially before it hits the surface. These partially dried droplets may look like bubbles. There's a chance that I'd have bad luck with glossy finish as well.


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## gsmarvel (Oct 17, 2013)

I have tried spraying it many different ways. Each time before the product dries it looks perfect under the lights. It is going on wet and flowing out. I believe the problem is something that happens as the finish is drying. I have used it before and it went well. However the last few times I used this high gloss I have had an issue. Each time the temp in the shop was around 60.



> I know minwax gets a bad rap sometimes, but I have good luck with it. I like the polycrylic. It gives me a good looking finish, especially since I exclusively use satin finish. It dries quickly, which allows me to often get three coats sprayed on a project in a day. Is there any chance there s an issue with how far you are holding the sprayer from the surface, holding it too far away gives the product a chance to dry partially before it hits the surface. These partially dried droplets may look like bubbles. There s a chance that I d have bad luck with glossy finish as well.
> 
> - firefighterontheside


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