Sorry about the last unfinished message regarding blistering. I was just getting started when my damned computor decided to send it- it's been doing things like that lately; guess I need a bigger hammer.
What I was trying to say was that sometime in the in the early 70's many of we builders started using a catalyst; called HiPoint 180 because we found that the parts made from it had much less porosity in the gel coat, and probably in the laminate as well, altho there was no way to tell that I could think of because you couldn't see it in the laminate. Shortly after that the EPA (or was it the Air Quality Control Board?) mandated that the manufacturer of 180 reduce the oxygen content, putting it in line with the product of its inferior competition. I heard at the time that this was a result of lobbying by the other chem companies. When I heard that 180 was not going to be available I bought an old refrigerator and bought several cases of 180 which lasted me for several years. I heard of no blisters on my boats during those years. The catalyst used for polye\sters (including vinylester and Ashland's AME; great stuff) is MEK Peroxide and it works by oxydizing the resin, which is a polymer. At the time someone from one of the resin companies told me that there is an ideal ration of oxygen in catalyst, which causes more of the solvents to leave the curing resin and go into the air. I suppose it's the opinion of the EPA that it's better that the solvents are in the resin than in the air, even tho its got to be an extremely small amount in the general scheme of things. At any rate we still have porosity problems in gel coat and resin, and I'd bet my bottom dollar that the porosity is connected with blisters. Better living thru bigger government, I guess is the theory. jerry _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
