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Re: S&G: keel seam
By:Mike Savage
Date: 1/22/2008, 8:28 pm
In Response To: S&G: keel seam (dave)

: Most S&G kayaks (unless they have a flat bottom) longer than 16ft. will have
: two panels meeting at the keel. Since the preferred joining method is to
: scarf panels together, how do you reconcile this long butted joint? Seems
: most people just tape it, at least on the inside seam. I'm just a little
: concerned about bursting apart at the seams, since on a good day I'm about
: 6ft., 190lbs. I'll search the archives tonight after work, since most
: topics have probably been discussed to death anyway...

: My intro...I'm in the San Fernando valley in Calif. Got interested in kayaks
: last fall. Bicycle quite a bit, hack wood in the garage, built RC
: Sailplanes in my younger days, figured, hey I can do this.

Hi Dave,
If the kayak is only seam-taped with the rest of the ply only coated with epoxy, there is tape on the inside and outside. Sometimes two layers of tape on each side are used, the second a bit wider than the first. Older designs just taped the seams and painted the hulls inside and out using marine ply, mostly 6mm (1/4").
Glassing the entire hull allows lighter ply to be used, 5mm (3/16") to 3mm (1/8"). The glass is generally so the weave is square to the keel line, or close to square. This allows the glass strands to be under tension at their greatest strength.

Thousands of kayaks and boats have been built like this, and I've never seen one split along the keel line. The total weight of kayak and paddler is supported by the entire kayak in the water, not much pressure per square inch. Plus, water tends to act as a cushion to a degree. (Unless in crazy water, then you want a 'tank'.)

Strip-built are usually built using carpenter's glue to hold the strips together before glassing, and that is no where near as strong a epoxy, and they hold up fine.

Hope this helps,
Mike Savage
South West Cork

Messages In This Thread

S&G: keel seam
dave -- 1/22/2008, 6:30 pm
Re: S&G: keel seam
Tom Raymond -- 1/23/2008, 10:55 am
Re: S&G: keel seam
Don Lucas -- 1/23/2008, 10:40 am
Re: S&G: keel seam
LeeG -- 1/24/2008, 2:50 am
Yes *NM*
Don Lucas -- 1/24/2008, 10:19 am
Re: Yes
Tom Raymond -- 1/24/2008, 2:59 pm
Re: Yes
LeeG -- 1/26/2008, 12:59 am
Re: Yes
Dave Reekie -- 1/25/2008, 4:52 am
reconciliation not needed
LeeG -- 1/23/2008, 4:19 am
Seams and joints
Paul G. Jacobson -- 1/23/2008, 2:31 am
Re: Seams and joints
dave -- 1/23/2008, 11:27 am
Re: S&G: keel seam *LINK* *Pic*
Dave Houser -- 1/23/2008, 1:54 am
Re: S&G: keel seam
Bill Hamm -- 1/23/2008, 1:50 am
Re: S&G: keel seam
vk1nf -- 1/22/2008, 9:05 pm
Re: S&G: keel seam
Mike Savage -- 1/22/2008, 8:28 pm
Re: S&G: keel seam
dave -- 1/23/2008, 12:00 am
Re: S&G: keel seam
Paul G. Jacobson -- 1/23/2008, 2:46 am