Polycrylic with thousands of bubbles

[Ric Altman]

I've been using Polycrylic for 7 years now without issue, foam brushes, good brushes and HVLP sprayer. All good until today. I've tried about 8 times to finish a project and regardless of the method, foam, quality brush or HVLP I get massive amounts of small bubbles. I have two cans of Poly, one maybe 8 months old and one much newer but same results with both. The only variable I can think of dawned on me at the end of the day after saying many, many bad words is that it has been raining all day. Normally I avoided those days but I just spaced it. Could this be the issue with the bubbles? Humidity? Shop is 72 degrees, clean air and freshly milled dry walnut with no prior finish other than 2 thin base coats of same Poly.

[Jim Becker]

Stirring, not shaking correct? Finish also at 72ºF?

[Ric Altman]

Stirring, not shaking correct? Finish also at 72ºF?

Stirred and 72 yes. Humidity is 84 %

[Prashun Patel]

What is the wood you are using? Can you share pictures?

[Ric Altman]

Walnut
IMG_0185.jpg

[Tom M King]

I remember when they first came out with it, that was all I could ever get, regardless of process. I just stopped using it.

[Andrew Seemann]

It almost looks like it is drying out before it is leveling, which is kind of the opposite of what you would expect a water based finish to do at 84% RH.

[John TenEyck]

I would take another piece of the same wood and apply a coat of Sealcoat shellac to half of it. When that's dry, say an hour later, coat the whole thing with your finish. Keep adding coats and observe which side the problem shows up on first. If it only shows up on the side w/o shellac then the problem is caused by the wood itself. If it happens on both sides then it's the finish or your application technique, and more likely the finish.

John

[William Fretwell]

I think it’s the porosity of the wood, despite the sealing coats. When the finish goes into the wood it displaces air which rises up to form bubbles. There are more bubbles next to the end grain which has more porosity.
You need many more thin coats to fill the voids before the final coats.

[Mark Bolton]

You could try heavily reducing. 15% or so. I ran a lot of that on residential interior trim and when we struggled with bubbles reducing was always a good option.

[Rich Engelhardt]

Are you brushing right out of the can? If so, are you dragging the brush across the lip of the can to remove excess?