On Sun, 25 Mar 2007 15:49:10 -0400, "Eisboch" wrote:

Ironically, it wasn't until the mid 70's that the blisters started showing
up on recreational boats. My father-in-law's was a '72 and was a
recreational version of one of the Vietnam era patrol gunboats (except the
military ones had jet drives instead of props). The fiberglass was rough
due to minimal upkeep, but there were no blisters.

The Uniflite Mega that I had was a '78 or '79. (I forget which) It had
blisters on the topsides, but none that we ever noticed below the waterline.

Best current theories about the mid-70s blister epidemic are that the
resin vendors changed their product formulation due to high petro
prices or that builders changed their wet out/gel coat procedures,
probably the former.