: Lee,

: If softening with increased temperature is an issue, then the choice of epoxy
: can have an effect. To compare epoxies, look at the heat deflection
: temperature or glass transition temperature (Tg). I just had a quick look
: at the MAS site and didn’t find any values for their stuff – same with
: RAKA. West System publishes values for their products. Fiber Glast has a
: short comparison table on their page, but it only has Tg values, and only
: lists WEST ProSet. But, if we add the Tg value of 137 F for West 105/207
: to the Fiber Glast table, it looks like a coaming built with West 105/207
: would soften at a temperature around 50 F lower than one made with Fiber
: Glast 2000/2060. However, I doubt that there would be that much difference
: between the brands that we commonly use.

: Making the coaming thicker will help prevent noticeable softening. I used
: around five layers of 6 oz carbon covered with layer of about 0.045 in
: veneer, and have not noticed softening. But the light color does help keep
: it cooler than if it were black.

: Sam

Good info. 50 degrees F is a big difference and like you say, no telling way RAKA is rated. I believe this will become an issue in the near future for a spec to pay attention to in our construction projects.

I made a magnetic hatch and cut a slot through, epoxied 1" webbing to the underside using Raka 127/350 (probably their softest), decided we didn't like it. Only took about 10 seconds applying a regular iron to pull it off by hand. Prior to that a chisel would not touch it!