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Use thin foam and leave it in place.
By:Paul G. Jacobson
Date: 9/9/2001, 11:37 pm
In Response To: Re: A new method to build a kayak.......??? (John Monfoe)

: . . .What I have in mind is bending panels
: of it over tempory station forms with banks of heat lamps and weights on
: the foam to relax it to shape. I'm sure there are many things wrong with
: this idea but there it is. Once the boat is built this way, I would
: fiberglass the whole thing on the outside and then strip out the inside of
: foam machanically and chemically. Just a thought.
: John

Nothing wrong with this concept. In fact, there is a web page somewhere which shows a glass/composite kayak being built this way.

But, you don't need to strip out the foam, and in fact, you priobabaly shouldn't. use a foam that is 3/16 to 3/8 inch thick. The thin stuff should bend easily, without weights, if you just coax it a bit with a heatgun. Work with pieces that are a foot to 2 feet wide and after they are shaped you just glue them together. When you have the whole form covered, with foam, you glass it on the outside, lift it off the form and glass the inside.

You'll need to build on top of a fairly substantial foundation, which will probably look like a half-made stripper. We're talking strongback, station forms, and covering the forms with loosely spaced strips of pine or cedar. (you can use staples without regrets) You need these strips to define the form of the curved shape you'll force your plastic foam panels into.

The starion molds must be cut smaller than those used for a stripper (subtract the thickness of the foam you'll use) as the outside of the hull will be applied to the layer of plastic foam, which is riding on top of the layer of strips.

Clark Craft had plans for a canoe built from foam like this, and they went over the process in their old printed catalog. Unfortunately I did not see much on this in their online catalog. (www.clarkcraft.com). They mention using a specific type of plastic foam sheet which seems to have a smoothly skinned surface.

Why do you leave the foam core in place? As with wood strips, the separation of the inner and outer layers of glass cloth by the core material adds stiffness and strength without adding the weight of a similar thickness of glass and resin.

PGJ

Messages In This Thread

A new method to build a kayak.......???
Mark F -- 9/8/2001, 1:26 am
Great idea for a fast sit-on-top kayak
Paul G. Jacobson -- 9/9/2001, 11:05 pm
Re: A new method to build a kayak.......???
John Monfoe -- 9/9/2001, 8:09 am
Use thin foam and leave it in place.
Paul G. Jacobson -- 9/9/2001, 11:37 pm
Re: Foam & glass Website
Dave Houser -- 9/10/2001, 3:04 pm
Re: Another one
Shawn Baker -- 9/10/2001, 3:34 pm
Why not ;) stripper with strips cut from foam :b ? *NM*
risto -- 9/10/2001, 12:40 pm
Peter Van Dyne did this 30 years ago
Craig Bumgarner -- 9/12/2001, 11:51 am
so, nothing new under the sun :) !
risto -- 9/13/2001, 10:27 am
Re: A new method to build a kayak.......???
tg -- 9/8/2001, 11:39 am
Re: A new method to build a kayak.......???
Mike Scarborough -- 9/8/2001, 3:17 pm
Re: A new method to build a kayak.......???
Tapio Manner -- 9/8/2001, 3:23 pm
Thanks everyone I've had this idea for years...
Mark F -- 9/8/2001, 11:09 pm
Re: Thanks everyone I've had this idea for years..
100GRIT -- 9/9/2001, 7:34 am
Re: Thanks everyone I've had this idea for years..
Rehd -- 9/9/2001, 12:05 am
Re: A new method to build a kayak.......???
Tapio Manner -- 9/8/2001, 4:11 am