Acrylic clear coat blistering

[Richard Demler]

Can anyone tell me why the clear coat acrylic on my bowls blisters when I set them outside to dry..They were in the sun but I did'nt think that would hurt anything..They don't blister all over the bowls just in end grain areas..Sometimes it happens to bowls that have been dry for 2 days already..Any thoughts are apprieciated..Thanks!

[Brice Rogers]

I'm guessing that there is either moisture or outgassing (from the acrylic). The end grain is like straws. That is where they absorb the most finish and also where the most moisture is emitted.

On a related note: I flooded a bowl with poly and a day or so after it was totally dry to the touch, I put it in the sun. The uncured poly that soaked in was apparently not fully cured and it squeezed through the pores and made it look like it was sweating.

[Roger Chandler]

Most non-penetrating finishes that harden over will blister in the sun. I built bathroom cabinets, vanity, chimney closet and a large mirror frame as the last piece to complete the bathroom remodel. The mirror frame blistered as I had applied the finish on saw horses outside. Had to re-do that frame. I used an exterior polyurethane because it is durable and a bathroom gets moisture.

[Richard Demler]

Thank you for the replies..I guess I'll keep them out of the sun when possible..