This can be a problem for literally any fiberglass body...
I uncovered or forced the pinholes to reveal themselves with a small plastic tipped hammer and tapping literally every square inch of the body on my car. Actually, I found a few air bubble voids as well where the fiberglass was not laying on the gel coat.
Yes, heat cycles will also help them show as the air pressure inside the void or pin hole will increase and cause the gel coat to fail at that point.
I uncovered or forced the pinholes to reveal themselves with a small plastic tipped hammer and tapping literally every square inch of the body on my car. Actually, I found a few air bubble voids as well where the fiberglass was not laying on the gel coat.
Yes, heat cycles will also help them show as the air pressure inside the void or pin hole will increase and cause the gel coat to fail at that point.