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Re: Weak Scarf Joints
By:Shawn Baker
Date: 3/24/1999, 12:12 pm
In Response To: Weak Scarf Joints (Dan Gunn)

> Well,

> Not minutes after someone posted a question about my using 3M bubbles as a
> thickener in my scarf joints, and the possible ramifacations to strength,
> did one break. Now what? I have to assume that all six joints are weak and
> I don't know how to fix it. Do I intentionally break all the joints re
> scarf them and re-epoxy them? I'll be losing some length, does this mean
> even more scarfs on the ends to add length? should I start over with new
> plywood? The instructions call for wood flour as a thickener, I'm told saw
> dust works as well, are they just for colour? Had I just used epoxy and
> hardener would the joint have been stronger? I had originally just used
> epoxy and hardener but added the only thickener I had because one of my
> CLC manuals said to, of course it doesn't say why (strength, colout etc.)

> Look forward to more of your wisdom. Dan

Hi Dan, I don't know if you've "intentionally broken" all 5 of your remaining scarfs, but it's possible that your epoxy just cured slowly. By now, 3 days later, they may have cured more fully. Everyone has pretty much agreed that the baloons weren't a great high-strength thickener, but don't completely abandon hope! You might just break one and see how much force it took. (Or just give it a good flex--if nothing happens, then don't force it to the breaking point!) If it is a lot stronger than the original broken joint, then just leave them alone and build your boat. The outside of the hull will, by the design, be covered with fiberglass. I'd put a 6-8" wide strip of glass on the inside of the joints, (after you stitch it together) and you shouldn't have anything to worry about.

Shawn

Messages In This Thread

Weak Scarf Joints
Dan Gunn -- 3/23/1999, 3:33 pm
Re: Weak Scarf Joints
Stan Heeres -- 3/24/1999, 9:01 pm
Re: Weak Scarf Joints
Shawn Baker -- 3/24/1999, 12:12 pm
Re: Weak Scarf Joints
Brian Barnett -- 3/24/1999, 10:40 am
Sounds like a new take on a "folding" ka
Pete Rudie -- 3/24/1999, 12:26 pm
Re: Weak Scarf Joints
Shawn Baker -- 3/24/1999, 12:13 pm
Re: Weak Scarf Joints
Byron Lawrence -- 3/24/1999, 10:38 am
Re: Weak Scarf Joints
Jack Martin -- 3/24/1999, 9:24 am
Re: Weak Scarf Joints
Shawn Baker -- 3/24/1999, 12:03 pm
Re: Weak Scarf Joints
Don Herring -- 3/23/1999, 8:49 pm
Re: Instructions & Weak Scarf Joints
Dan V -- 3/23/1999, 5:30 pm
Re: Instructions & Weak Scarf Joints
Larry C. -- 3/23/1999, 6:50 pm
Re: Instructions & Weak Scarf Joints
Pete Rudie -- 3/24/1999, 12:35 am
Re: Weak Scarf Joints
Kenneth Paul -- 3/23/1999, 5:08 pm
Re: Weak Scarf Joints
Mark Roberts -- 3/23/1999, 4:40 pm
Re: Weak Scarf Joints
Pete Rudie -- 3/24/1999, 12:42 am
Re: Weak Scarf Joints
Dan Gunn -- 3/23/1999, 4:50 pm