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Spraying High Gloss Polycrylic drys with micro-bubbles

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Forum topic by Gregg M. posted 02-04-2016 11:16 PM 931 views 0 times favorited 19 replies Add to Favorites Watch
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Gregg M.

170 posts in 1147 days


02-04-2016 11:16 PM

Topic tags/keywords: polycrylic finish micro bubbles minwax polycrylic

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.

-- Marvel Woodworking, West Chester, PA - http://www.MarvelWoodworking.com


19 replies so far

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InstantSiv

259 posts in 1060 days


#1 posted 02-04-2016 11:51 PM

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

955 posts in 617 days


#2 posted 02-05-2016 12:56 AM

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

-- Knowledge and experience equals Wisdom, Michael Frankowski

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JAAune

1645 posts in 1782 days


#3 posted 02-05-2016 01:13 AM

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.

-- See my work at http://remmertstudios.com and http://altaredesign.com

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dhazelton

2325 posts in 1762 days


#4 posted 02-05-2016 01:15 AM

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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Gregg M.

170 posts in 1147 days


#5 posted 02-05-2016 01:20 AM

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.

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.

- InstantSiv


-- Marvel Woodworking, West Chester, PA - http://www.MarvelWoodworking.com

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Gregg M.

170 posts in 1147 days


#6 posted 02-05-2016 01:21 AM

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


-- Marvel Woodworking, West Chester, PA - http://www.MarvelWoodworking.com

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ScottM

346 posts in 1612 days


#7 posted 02-05-2016 01:37 PM

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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mahdee

3553 posts in 1233 days


#8 posted 02-05-2016 02:44 PM

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).

-- earthartandfoods.com

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Gregg M.

170 posts in 1147 days


#9 posted 02-05-2016 03:13 PM

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.

-- Marvel Woodworking, West Chester, PA - http://www.MarvelWoodworking.com

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Gregg M.

170 posts in 1147 days


#10 posted 02-05-2016 03:15 PM

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


-- Marvel Woodworking, West Chester, PA - http://www.MarvelWoodworking.com

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ScottM

346 posts in 1612 days


#11 posted 02-05-2016 03:56 PM

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

1417 posts in 642 days


#12 posted 02-05-2016 04:01 PM

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?

-- "I love it when a plan comes together" John "Hannibal" Smith

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ScottM

346 posts in 1612 days


#13 posted 02-05-2016 04:23 PM

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

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JAAune

1645 posts in 1782 days


#14 posted 02-06-2016 03:20 AM

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.

-- See my work at http://remmertstudios.com and http://altaredesign.com

View JackDuren's profile

JackDuren

137 posts in 425 days


#15 posted 02-07-2016 02:18 AM



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.

- Gregg M.


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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