I watched a show on the Discovery Channel Monday night about new bridge building technology. They showed an interesting way to make a piece of fiberglass "board" by taking foam board and sandwiching it between fiberglass cloth and then injecting it with fiberglass threads in an x pattern. Has anyone ever used this to construct a kayak? If it didn't weigh too much it would build flotation right in. Jim et al *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Of course, a surfboard is a foam blank surrounded by glass. The "x" threads must be the key to added strength. I wonder if any surfboard or kiteboard manufacturers have adopted this technology; it's probably more critical, and thus more cost effective, to bridge supports than minimizing snapped surfboards; however, I wonder if this technology would allow the production of lighter surf kayaks while still maintaining strength with a foam core hull featuring "x" threads--interesting idea! Craig ----- Original Message ----- From: "Jim" <jfarrelly5_at_home.com> To: <PaddleWise_at_paddlewise.net> Sent: Wednesday, February 27, 2002 8:07 AM Subject: [Paddlewise] Fiberglass laminate > I watched a show on the Discovery Channel Monday night about new bridge > building technology. They showed an interesting way to make a piece of > fiberglass "board" by taking foam board and sandwiching it between fiberglass > cloth and then injecting it with fiberglass threads in an x pattern. Has > anyone ever used this to construct a kayak? snip *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
From: "Jim" <jfarrelly5_at_home.com> > I watched a show on the Discovery Channel Monday night about new bridge > building technology. They showed an interesting way to make a piece of > fiberglass "board" by taking foam board and sandwiching it between fiberglass > cloth and then injecting it with fiberglass threads in an x pattern. The x pattern fibers will pick up the shear forces that the foam is not strong enough to carry. This makes it significantly stronger than just a normal foam/fiberglass sandwich. Quite some time ago we had a discussion on PW about using core materials to make stiffer and stronger kayaks. The problem is finding a core with enough shear strength to make it work. After that discussion, I thought about using a 3D woven material (vaguely like the tricot lining in 3 layer GoreTex) that combines two surface layers with a lattice of crossed fibers internally. Inject with foam and coat with resin and you're done. I talked to a couple of folks about it, but it probably isn't cost effective. You wouldn't need a very thick core to create a stiff kayak. However, two groups would likely chime in. The stitch and glue crowd will eagerly point out that glassed okoume kayaks are just as good, cheap and easy to make and the skin on frame gang will point out that kayaks are best when they're flexible. Mike *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
At 10:16 AM 2/27/02 -0500, Michael Daly wrote: >From: "Jim" <jfarrelly5_at_home.com> > > > I watched a show on the Discovery Channel Monday night about new bridge > > building technology. They showed an interesting way to make a piece of > > fiberglass "board" by taking foam board and sandwiching it between > fiberglass > > cloth and then injecting it with fiberglass threads in an x pattern. > >The x pattern fibers will pick up the shear forces that the foam is not >strong enough to carry. This makes it significantly stronger than >just a normal foam/fiberglass sandwich. > >Quite some time ago we had a discussion on PW about using core materials >to make stiffer and stronger kayaks. The problem is finding a core with >enough shear strength to make it work. After that discussion, I thought >about using a 3D woven material (vaguely like the tricot lining in >3 layer GoreTex) that combines two surface layers with a lattice of >crossed fibers internally. Inject with foam and coat with resin and >you're done. I talked to a couple of folks about it, but it probably isn't >cost effective. > >You wouldn't need a very thick core to create a stiff kayak. However, >two groups would likely chime in. The stitch and glue crowd will >eagerly point out that glassed okoume kayaks are just as good, cheap >and easy to make and the skin on frame gang will point out that >kayaks are best when they're flexible. As one of the "stitch and glue" crowd I'll respond to the invitation to chime in. Typically stitch and glue kayaks using fiberglass over okoume don't create a "core" because the fiberglass cloth is often only on the outside of the hull and in strategic place where a little more protection. On my S&G boat there is cloth tape down the keep line and lighter cloth over the entire outside of the hull. On the inside, the seams have fiberglass cloth, and even though it wasn't required in the building instructions I put down cloth on the bottom of the cockpit area for abrasion resistance, behind the cockpit to stiffen it up for reentries, and around the hatch openings (I made flush hatches). The deck has no fiberglass cloth on it whatsoever. I would imagine that very few S&G wood kayaks are actually fiberglass-wood-fiberglass sandwich for the entire boat. However, kayaks or canoes built using strips (usually cedar) *are* constructed using a fiberglass-wood-fiberglass sandwich (I'm currently building one of those too) and would have similar benefits. I also wouldn't put too much credence into the benefits of a foam core as a significant aid to floatation. I haven't particularly noticed that my wood kayak floats better than my fiberglass boat or a plastic boat. The floatation doesn't come from the material as much as the use of bulkheads or inflatable bags to displace water (ever seen a cement boat?). If a fiberglass kayak and foam core were both completely full of water, the foam core boat might float a bit higher instead of being neutral but both boats are going to be pretty useless until most of the water is emptied from the inside of the hull. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
From: John Fereira "....The deck has no fiberglass cloth on it whatsoever. I would imagine that very few S&G wood kayaks are actually fiberglass-wood-fiberglass sandwich for the entire boat....." Only on the hulls of multichine designs. With the width of the tape and the narrow panels you might as well use cloth on both inside and out. Decks are normally not fiberglassed or else fiberglassed on top only. Cheers Grant *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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