[XYZ]

Everyone here claims you need to use oil based primers outside. Stix is formulated for glossy hard to stick to surfaces. Wood is porous, so its kind of a different category. It could be that gases in the wood pores expanded in the heat... Maybe you didnt let the primer dry long enough before topcoating... The best thing for exterior wood is something that penetrates , which isnt really what STIX is designed for. Not saying its not good for wood, but in your situation, a penetrationg primer like an oil base would get in the pores deeper, and you'll have LESS of a chance of that happening.

Very good points Woodco.

I'm shocked that B/M guy didn't suggest 'long oil primer' made by B/M, excellent oil primer for exterior wood.

 

[XYZ]

That is why you never take the rep's word as gospel.

Peeled off the bubble and it was bare wood so guess it was the primer. What!!! I thought primer never came off. Would that just be the heat? I used Insl-x STIX- Waterborne bonding primer. guy at Benjamin Moore said it was the best. MMMMMM
P.S thanks for you all help guys. Been in the painting scene a year now and slowly learning there is so much to learn.

Maybe it was just a clerk guy, not real sales rep.
But even clerk should know to suggest long oil for wood, especially exterior.