: You might save a pound, maybe only 1/2 a pound, switching these on
: just the outside of the deck. Inside of the deck would be
: another pound saved. Maybe.

: Here is how it works: the best mix is to use an equal weight of
: resin to glass. That rarely happens. To fill the weave and get a
: smooth coat we usually use excess resin. It takes about a gallon
: to a gallon and a half of resin to cover a solo kayak. At 8
: pounds to a gallon, your resin is going to weigh 8 to 12 pounds.
: So your glass will weigh about the same. Total weight for
: glassing is 16 to 24 pounds (Typically). The rest of the weight
: of your boat is the wood. That typically ranges from 22 to 35
: pounds.

: First-time builders tend to go heavy with their materials. They
: don't trust the strength of these materials because they haven't
: got any experience with them. And they waste a lot, so they may
: use 1.5 gallons of resin, but only 1 gallon remains on the boat
: after sanding off boo-boos. So, these numbers are probably a bit
: on the high side. Even so, the strip-built boat is considerably
: lighter than a fiberglass kayak.

: Going with thinner glass means the resin coating can be thinner,
: and still fill in the weave pattern. Working with 3-ounce or
: 4-ounce glass you might build a boat with 3 to 3.5 quarts of
: resin (about 6 to 7 pounds) and glass of the same weight. A
: total of 12 to 14 pounds for the fiberglass work. You save
: anywhere from a pint to a quart of resin compared to a careful
: worker using a thicker 5 or 6 ounce glass.

: If you want to save weight, go for savings in the hull (bigger area
: to cover, more room for waste), use 3/16" strips instead of
: 1/4" strips, weigh your boards at the lumberyard and buy
: the lightest ones, use 3 ounce glass (S or E), make a large
: cockpit (less wood), and/or build a smaller boat. Or, build a
: skin-on-frame boat design. Not a lot of wood to them, no
: glassing, and the hull and deck are fabric. It's not too hard to
: get a SOF kayak in the 20 to 25 pound range, and most will be
: under 35#.

: Just curious. What model boat are you working on, and why the worry
: about such a small weight savings? If you were building the
: entire boat to win some contest for 'superlight" (and I
: don't know of any such contest) then 6-ounce glass would never
: have been part of the plan.

: I'm not too sure exactly what info you need on s-glass, but
: www.Fibreglast.com has some good info on glass online. You might
: browse there. one thing: S-glass stands for Strength. the other
: glass cloth was originally designed for use as an electrical
: insulation, and is called E-glass. E for electrical. As it
: happens, the E-glass, besides being a fine insulator has great
: strength and serves as the base of most fiberglass products.
: There are a million recipes for glass. Using one which gave
: stronger fibers they created S-glass. For a given fiber diameter
: and weight it is stronger by about 25 to 30% (if I remember
: correctly). It is not as common, so the price is higher. People
: who want greater strength frequently go to the really expensive
: materials, carbon fiber, kevlar, spectra, or mixes of these
: instead of glass. That kind of cost is usually a budget-breaker
: for the home builder. www.defender.com sells these and has some
: prices and info on them in their catalog. It takes a bit of
: digging to find it on their web site, but it was there when I
: last looked.

: Hope this helps.

: PGJ
Thanks for all the informaion. The reason I am looking for a light layup on the deck is that I am making a very unusual decrative deck material and design which is heaver than just cedar strips. I will post a picture when I get futher along. Thanks agian for the advice.