Right. Most hulls with a resin/hardener system are polyester; not epoxy. Sorry, I mis-stated that in the last post. I should have written polyester, not vinylester. I had heard of the blister hulls that happened to the Valiant production; but was not sure if it was only limited to their boats or if it was more widespread.
Here is a quote from masepoxies website:
To understand the repairing of blisters, we should first understand the cause. Polyester Resin is used in the production of 90% of the boats now afloat and is not waterproof.