the mistakes never end when learning to make boards (atleast for me) left this in my truck bed with a taneu cover and ended up with a huge air bubble on the deck poor glass job or dont leave fresh glassed boards cooking in a car? haha
Have had similar experience with board getting real hot while resin still soft. Bummer.
Vented Leash Plugs prevent that from happening
http://greenlightsurfsupply.com/products/surfboard-vented-leash-plug-v314?variant=1052038943
what is the construction?
Correction: Don’t ever leave any board “cooking” in a hot car - especially not you you’d like to last you and especially not epoxy. Heat turns moisture to gas and the trapped gas has nowhere to go but out, hence the bubble. But even if you did have a perfectly dry blank with 0% moisture content it’s a terrible thing to do to a board. And even if it weren’t epoxy and you left a perfectly dry poly board in the car - the heat would cause the VOCs in the resin to seep into the air: hence why when you get back into your car on a hot day it smells like a glassing factory.
Keep them in a board bag or a sock at least.
These days although the quality of Poly foam by the "big Three is far superior to the old Clark; there can still be problems with batches and pours. Most likely though your board was not post cured and poorly cared for. There’s no one to blame but yourself.