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Re: S&G: An Olde Butt Joint question
By:Geoff
Date: 9/10/2010, 6:25 pm
In Response To: Re: S&G: An Olde Butt Joint question (Robert N Pruden)

: This is exactlyhow I do it, Wes. I always get butt joints that are
: smooth and strong. Never have a busted a kayak at a butt joint.

To add to Robert's observation and the other comments about butt joints I have now tested quite few versions including the Pygmy one with both sides taped.

All test pieces were the same size and were the usual 4mm plywood. I compared all of the joint versions with a solid piece of plywood with no joint at all. I compared when each broke relative to that standard.

All the joints failed under less pressure than the solid piece (not a shock really - although they all held beyond the curves they would be subjected to as part of a kayak as far as I can tell) EXCEPT the Pygmy technique. That joint was stronger than the surrounding plywood and the break, when it happened, was outside the taped area! So the taped butt joint (both sides) was simply stronger than the plywood. It did not break.

My splined joint was the next best. My splined joint with FG tape on the inside was next and did better than the simple butt joint with tape only on the inside. So the clear winner for strength is the Pygmy technique!

Messages In This Thread

S&G: An Olde Butt Joint question
Geoff -- 9/6/2010, 1:50 pm
Re: S&G: An Olde Butt Joint question
Sodbuster------WebKitFormBoundary6pLaVD9X7Zfw4+Pi- -- 9/6/2010, 2:17 pm
Re: S&G: An Olde Butt Joint question
Wesley Ewell -- 9/6/2010, 7:08 pm
Re: S&G: An Olde Butt Joint question
Robert N Pruden -- 9/9/2010, 6:09 pm
Re: S&G: An Olde Butt Joint question
Geoff -- 9/10/2010, 6:25 pm
Re: S&G: An Olde Butt Joint question
Geoff -- 9/17/2010, 4:20 pm
Re: S&G: An Olde Butt Joint question
Geoff -- 9/7/2010, 9:17 am
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/7/2010, 12:00 pm
Re: S&G: An Olde Butt Joint question
Geoff -- 9/7/2010, 7:22 pm
Re: S&G: An Olde Butt Joint question
Sodbuster -- 9/8/2010, 8:16 am
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/8/2010, 11:58 am
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/8/2010, 11:39 am
Re: S&G: An Olde Butt Joint question
Wesley Ewell -- 9/8/2010, 11:57 am
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/8/2010, 12:09 pm
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/8/2010, 12:01 pm
Re: S&G: An Olde Butt Joint question
Sodbuster -- 9/8/2010, 2:12 pm
Re: S&G: An Olde Butt Joint question
Bill Hamm -- 9/8/2010, 3:31 pm