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Anyone know what this might be? Im spraying lacquer and am wondering if its moisture? Ive sanding them down 2 times and resprayed and they keep popping up.

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Do they keep popping up in exactly the same spots? If you sand one down very carefully - look with a good light shining across the finish and see if you see a fine little whisp of hair/fuzz sticking up.. If so - it's dust/lint/hairs.... Groan...

Let's just say that in my context - "The hair of the dog" refers to special inclusions in my finishes, not something fun the night before.

I also noticed that dandruff would get into lacquer finish. In my example, the final leveling and buff out left them not visible.

That looks like "solvent pop". This is caused by the finish curing before the solvent has had a chance to escape. A bit of retarder in the lacquer will fix this.

If viewed with a 10x hand magnifier, do they look like volcanoes or mountains? Something that looks like a raised ring with a depression in the center might be an open pore or (if a bit larger that what is evident in your shot) a fisheye, while a mountain-like hump is probably dust or other debris. You might consider scraping level before shooting the next coat in either case.

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For the times they are a changin'

- Bob Dylan

I scraped and sanded them down then they reappeared when I shot a new coat...... grrrrrr. Ok I think I'll try the retarder.

I sprayed out about 40 other cabinet doors with out any problems and the raised bumps was random fyi

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Solvent popping usually occurs during hot weather when the lacquer cures quicker. Sherwin Williams sells a special lacquer thinner with some retarder added to handle the summer season here in Houston. Or you can buy a can of retarder and add it yourself.

Did you shoot in the sun? Temp? RH? All 40 doors received the same sand and fill?

_________________
For the times they are a changin'

- Bob Dylan

Solvent pop.
Here is a handy problem solving chart I made for spray finishes. https://howardguitars.blogspot.com/2015 ... rt_18.html

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks for the info fellas mucho gracious

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I was shooting in the shade. it was a bit on the cold side like maybe 60-65ish.

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I've had that happen when I've sprayed a finish in a cold environment and taken it to dry in a warm environment (to avoid blushing). I blame it on the piece losing moisture trying to regain equilibrium with the relative humidity in the new (dryer) environment. The moisture coming out of the wood's pores causing the air bubbles as the finish cures.