Bubbling paint

[Marc]

I'm on the first wall of installing all new cornice finish. My house.

I bought clear fir fascia, treated it with boiled linseed oil, left it to dry for several days, SH oil primer, 2 more days to dry and now I'm starting the first SH top coat and before I even finish the first four boards, the stuff starts bubbling up like some sort of primordial soup.

What did I do wrong? I painted in broad sunlight, is that it?

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Marc

[Chad Fabry]

That's from vapor drive.

[Marc]

In that case, it sounds like the vapor drive arose from laying the fascia boards in direct sunlight. That means I need to strip all paint from one side, expose it to sunlight for a day to dry it out then paint again, yes?

I painted it while it sat on sawhorses. 2nd coat comes after it's installed.

Marc

[Chad Fabry]

I wouldn't go to all that trouble.

It may or may may not be from moisture in the lumber- it could also be from the BLO. BLO takes weeks to fully cure. My bet is you applied the oil based primer in full sun, its skin cured quickly and prevented the balance of the VOCs in the oil paint and/or BLO from evaporating as they would have liked.

Fix just the bubbles or better, just install the bad side in.

[Marc]

I wouldn't go to all that trouble.

It may or may may not be from moisture in the lumber- it could also be from the BLO. BLO takes weeks to fully cure. My bet is you applied the oil based primer in full sun, its skin cured quickly and prevented the balance of the VOCs in the oil paint and/or BLO from evaporating as they would have liked.

Fix just the bubbles or better, just install the bad side in.

Ok. I scraped off the bubbles and loose paint and will paint again week after next, this time in my shop.

Headed for Sedona, AZ tomorrow and Los Angeles afterwards. Might be looking some of you guys up.

Thanks, Marc