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S&G: Outrigger shear scarf goes bang! *LINK*
By:Brian T. Cunningham
Date: 12/21/2002, 9:41 pm

I cleared space down in the basement and put the bulkheads are put back in. That's were the trouble starts.... The aft bulkhead goes in no problem. I used zip ties to help pull the sides together. The forces proved to be so great, that I needed to clamp pieces of wood to the bulkheads to keep them from buckling.

The forces on the forward bulkhead proved to be great for a shear scarf. It failed, ripping up the inner layer off the ply. I need to undo all I just did to repair both the scarf and the ply.

Seems that the forces involved in getting this rather thick plywood to bend are greater than I anticipated. Since the outriggers are 20ft long, I didn’t want to use a thinner ply. While I'm taking it apart to repair the failed scarf, I may redesign it:
1) Too much lose of depth of the keel at the stern. Take a look at the “comparison” photos.
2) The aft bulk is too wide.
3) The keel angle it too wide.
4) Torturing the wood puts a lot of stress in the hulls.

I may go back to a simple stitched Vee bottom design. Keep in mind that the outrigger will be mounted bow up, to help them go over waves. So the shear was never intended to be level.

Messages In This Thread

S&G: Outrigger shear scarf goes bang! *LINK*
Brian T. Cunningham -- 12/21/2002, 9:41 pm
Re: S&G: Outrigger shear scarf goes bang!
Rick Allnutt -- 12/22/2002, 7:41 am
Shear is fixed.
Brian T. Cunningham -- 12/22/2002, 4:15 pm