Originally Posted by fstbttms
My understanding is that water pressure can keep the blisters from protruding while the boat is in the water. Once the boat is on the hard
, lack of that water pressure allows the blisters to become evident.
Interesting theory, but it doesn't add up for me.
If the blisters are near the waterline, the water pressure is near zero.
Even if a 1/4" diameter blister was 3 feet below the waterline, the water pressure against the hull is only 7psi, or a grand total of 1.4 lbs force against the blister.
I can't imagine how this low amount of pressure could be greater than the pressure of the acid/gas in the blister causing the frp / gelcoat
Then again, I've been fooled before.