Hi,

With the 'glass on strip-built boats providing the strength, and the strips just holding them apart (and looking nice), do the two layers of fiberglass cloth need to be the same weight? To put it in context...

I am building the Night Heron with 3.5mm thick WRC strips. I want the boat strong but not too heavy. I planned to use 6oz (200gsm) glass on the outside, but then was going to use 4oz (130gsm) on the inside to save weight. But, will this make the hull less stiff/strong/impact resistant?

I know the inside glass will stretch if I hit a rock - will the above configuration unduly weaken the boat (especially given the thinner-than-usual strips) for a sligh weight saving?

Should I use 6oz on the inside also and just be extra careful with the epoxy?

Interested in peoples' thoughts.

Oh, I am using the 3.5mm wood as it was available, and obtained off others who used it for a kayak and rowing shells. So it works, just need to be light-handed with the sander!

Thanks,
Darren
Melbourne, Australia