Originally Posted by tidewaterv
any cruising boat that has hull that is laid up glass WITHOUT a core material like balsa core or similar is a real safe start in a search .many early hulls before 1973 were made of different glass than those later.early were polyester &much harder & stronger ....also most polyester hulls do not get the pox...better known as blisters...almost any hull by c&c,hughes_canada..hinterholler,belleville marine made before 1973 should be considered.manufacturers changed because of cost but mostly because of molds catching fire..very flamable materiels before they harden...most people are not aware of these changes...but smart buyer s in the know will take this into consideration..
Lots of incorrect and/or bad info in that post. C&C's have had balsa hulls on many models practically back to their inception - they were a leader in that kind of build.
The glass didn't change much until the 80's - old boats are all mat and roving. Lyasil (unidirectional) glass was pretty high tech in the mid 70's. IIRC it was the 80's before uncrimped (bi-axial) fabric was developed.
The boats with pox are almost universally polyester resin. Vinylester was a response to pox which is pretty well understood to have been caused by resin reformulations after the oil embargoes (along with some questionable laminating practices)
You actually don't want an overly hard resin - it's brittle. That's one of the big advantages to epoxy - it remains quite flexible after it's cured. Polyester resin is like rock candy when it's cured which means no "toughness". Let some pure poly resin cure and drop it on cement - you'll see (wear glasses)