Re: Building light

Posted by Mike on Jan 25, 2006

I built my S&G NH extra strong and light. It is an 18 footer that weights in at 36 pounds. I wanted it tough enough for surf and rock gardens, yet light enough to be easy on my bad back. I think I accomplished what I was shooting for.

It is made with 4mm BS1088 plywood. It has 2 layers of 6 oz satin weave s-glass over the entire outside of the hull, I layer of the same on the outside of the deck. I used 5 oz tight weave for the entire inside. I put a seal coat on all of the panels before stitching, but glassed the inside after it was stitched, being very careful to avoid ANY excess epoxy from pooling. I kept my fillets small, tiny to be exact. The coaming is glass, with no wood core, I built it over a foam mold, then tore out the foam. I used the forward bulkhead as a footbrace padding it out with foam. To make it lighter, but still as strong as a standard 6 oz on both sides of 4mm layup, I could have gone down to 3mm plywood, and only used one layer of glass. I figure that I could have gotten it down to 30 pounds that way, nat bad for an 18 footer.

Some tricks to building light are using small fillets, not letting any epoxy pool anywhere, do not use end pours, minimizing heavy hardware, such as footbraces and metal fittings, not using stacked wood coamings, squeegeeing your glass to eliminate floating, and using satin and tight weave glass. One cautionary note, satin, tight weave, and s-glass are more difficult to wet out, using a thin epoxy like System Three Clear Coat helps a lot. S-glass gives more strength for its weight, so less cloth is needed for a given strength.

I got a lot of these tips from Ted Henry. I've posted a link to his lightweight tips page below. Poke around his site some, he has also done some ding tests of various layups.

Mike

In Response to: Building light by TB on Jan 25, 2006

Replies:

• A Common Thread by Kurt Maurer on Jan 25, 2006