Messin' with thwarts

Willard · Post by **Willard** » Fri Oct 05, 2007 9:04 pm

I have an old ('89) Bluehole Sunburst OC-1. I don't like the beaminess and thought I might experiment. Has anyone ever adjusted the beam (the plan is to remove the aluminum thwarts and hack off about an inch) on an OC-1? I wonder what it might do to secondary stability, etc.. However, for the sake of the c-boat community, I just might go ahead if it turns out that this has not been attempted. Please let me know if you have experience in this realm.

cheajack · Post by **cheajack** » Fri Oct 05, 2007 9:09 pm

Heck, my Ocoee is pulled two inches. Why don't you make some wodden thwarts and cut 'em two or 2 1/2" and if you don't like the result you can always spread it and put your old aluminum ones back in?

Mike W. · Post by **Mike W.** » Fri Oct 05, 2007 9:27 pm

I second cheajack's idea.

Generally you'll lose a little rocker & some primary stability by pulling it in. You'll gain some speed too

rnbeals · Post by **rnbeals** » Fri Oct 05, 2007 10:14 pm

My 16 foot Dimension is far from an OC-1, but I tinkered with the thwarts because I bought it without thwarts, decks or seats.

My experience is that the biggest effect of pulling in the thwarts is loss of rocker, making the boat longer and faster. The gunwales are tighter but the waterline hull cross section was not affected much.

I finally got measurements off another Dimension and returned it to its original shape - I think the original design worked best (for this boat).

Rich

Post by **sbroam** » Sat Oct 06, 2007 12:12 am

I tinkered with my ME and took some measurements a while back - results here :

http://cboats.net/cforum/viewtopic.php?p=9766#9766

I'm thinking of tucking it in some more...

ezwater · Post by **ezwater** » Sat Oct 06, 2007 12:30 am

Y'all pull in your gut and leave your boat alone !

pblanc · Post by **pblanc** » Sat Oct 06, 2007 1:43 am

I have a Dagger Impulse that I have set up primarily as a whitewater tripping canoe pulled in about 1 3/4 inches. It did make cross strokes easier and seemed to improve speed and tracking a bit I presume by decreasing rocker and increasing waterline length.

Willard · Post by **Willard** » Sun Oct 07, 2007 11:54 am

I like the feedback!

I will try the oak thwarts and save the old aluminum ones for a refit if things don't go well. As it turns out, we had some big limbs cut down from a nice red oak in our yard, so I'll hack two thwarts out of that and screw 'em in. Now all we need is water up here!

Thanks again for the ideas!

philcanoe · Post by **philcanoe** » Sun Oct 07, 2007 4:52 pm

have experimented using c-clamps and longer wood, on flat - but moving water...simply placed across gunwhales and clamped....made it real easy to dial in desired width... go too wide, go not wide enough....also can lay boat on flat and measure rocker change... learned a lot about the boat, different hull materials, and how it affects performance for THAT hull