Sheer Clamp question

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Conrad
Posts: 119
Joined: Thu Feb 11, 2016 10:17 am
Location: Kathleen GA

Sheer Clamp question

Post by Conrad » Sat Sep 29, 2018 2:46 pm

Is there any reason I cant butt join a sheer clamp over a frame? Especially since the sheer clamp will be a lamination of 2 pieces
Keep your lines tight!

Conrad

Consider what God has done: Who can straighten what he has made crooked? Ecc 7:13 :)

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Roberta
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Location: East Troy, Wisconsin

Re: Sheer Clamp question

Post by Roberta » Sat Sep 29, 2018 3:51 pm

I would put any butt joints in areas with the least amount of bend. Maybe add some blocking on both sides of the frame where you join so you have adequate material to screw into. Try to keep joinery symmetrical so bends stay symmetrical.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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Conrad
Posts: 119
Joined: Thu Feb 11, 2016 10:17 am
Location: Kathleen GA

Re: Sheer Clamp question

Post by Conrad » Sat Sep 29, 2018 4:35 pm

Thanks Roberta. I was in a time sensitive situation, so I went ahead and did the butt joint. I placed it over frame 3, a straight, no bend portion. It will be laminated and I will place the break somewhere away from that spot. Thanks for the reaponse!
Keep your lines tight!

Conrad

Consider what God has done: Who can straighten what he has made crooked? Ecc 7:13 :)

mickfly
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Joined: Mon Jan 29, 2018 9:19 am

Re: Sheer Clamp question

Post by mickfly » Mon Oct 01, 2018 11:24 am

I know you've solved the problem, but for future reference...and future builders.

I could not get longer length douglas fir for my longitudinals...so I made scarf joints to turn 2, 12 footers into ~22 footers.

You can find lots of you tube videos on scarfing, but I basically put a piece of flat plywood on top of three, 2X 4 blocks to allow for clamping. I oriented the first board end on the plywood with the edge slightly over the edge of the plywood. I then struck a line 9 inches back from that first board edge. The second board was placed on top of the first board, but pulled back to the 9 inch line. Then I used a straight edge to mark an angled line from the bottom leading edge of the first board, through the intersection of the two boards at 9 inches and followed the straight edge up to the top...essentially making two equal sized triangles. Then I power- and hand-planed down to the line (planed off both triangles). A little epoxy on the two angled surfaces and lots of clamps and cauls to even out the pressure...one long board.

Time will tell if the scarfing worked, but so far they have held up (pre-flip).

By the way, I used the butt-joint blocking method Roberta described, on my sail boat build about 10 years ago. It worked well.

Mick

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Conrad
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Joined: Thu Feb 11, 2016 10:17 am
Location: Kathleen GA

Re: Sheer Clamp question

Post by Conrad » Mon Oct 01, 2018 12:06 pm

Thanks Mick! I scarfed the longitudinals, but butt joined the laminated sheer clamps.
Keep your lines tight!

Conrad

Consider what God has done: Who can straighten what he has made crooked? Ecc 7:13 :)

boisebrit
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Joined: Wed Jul 27, 2011 6:42 pm
Location: Boise, Idaho

Re: Sheer Clamp question

Post by boisebrit » Mon Oct 01, 2018 1:54 pm

Know you are done but but as reference for others this worked pretty well for scarf joints - a simple jig for the table saw and then one for glue up allowing easy clamping, wrapped wax paper around so the whole thing didn't stick to the jig. Attached couple of pics.
Attachments
battens-glue.jpg
battens-feather.jpg

mickfly
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Joined: Mon Jan 29, 2018 9:19 am

Re: Sheer Clamp question

Post by mickfly » Tue Oct 02, 2018 12:28 pm

Excellent tip, Bryan.

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