Builders' Forum Archives
Re: fibreglassing hull
Posted by CLC on Jun 6, 2005
Older generation epoxies, such as the ones prevalent when the Cape Charles 18 book and article appeared in 1991 (14 years ago), had higher viscosities. This meant that it was no sure thing that you could both saturate the fiberglass fabric with epoxy AND stick it thoroughly to the wood before the epoxy went off.
So it was common to attack the 'glass from both sides, as it were. First you'd roll out epoxy on the surface to be 'glassed, and that would set about soaking into the wood. Then you'd lay down the 'glass fabric, and if it was hot outside, you'd have the very devil of a time getting the fabric to smooth out on the sticky surface. Then you rolled on epoxy. This gave reasonable assurance that there was enough epoxy everywhere. For small patches of 'glass, or 'glassing on a vertical surface (it comes up from time to time), the epoxy-first thing is still pretty handy.
In the mid-1990's, viable epoxy systems with low viscosities entered the market. Now you could get your fiberglass all smoothed out on a clean, dry surface before you mixed a drop of epoxy. The thin epoxy penetrates the fabric and soaks into the wood, all in one shot. Infinitely easier. We switched to low-viscosity epoxy and never looked back.
In Response to: fibreglassing hull by John McKenzie on Jun 6, 2005