Putting Knees in Gunnel

[abl1111]

Has anyone successfully installed knees under the gunnels of their boat. I have a 23' Tsunami and want to do just that.

My gunnels have too much wiggle and I want to tighten that up.

[abl1111]

Any fiberglass/structural guys around ?

If not on CSC, where online can I gain perspective on this topic ?

Thx

[Terry England]

Hang on to see if someone knows an easy way to add some stiffener knees for your deck. My method involves removing engines, batteries and fuel tanks, and using cranes and forklifts to overcome the forces gravity. It's kind of expensive to do it this way unless you have a crane and forklift sitting around. (My life is a exercise in doing things the hard way - I work on an antique Bertram for three years to be able to launch it just in time to go out in the Red Tide. What the ^#%$!!* is with that)

[McGillicuddy]

Have you re-seated, re-glued and re-screwed or riveted the cap back on? That alone would offer tremendous rigidity. If you haven't done that, I would consider that first. A lot of guys here work their TSceptres pretty hard, but I don't recall this being a common problem

Are the original rod holders attached? That might offer some support...

[uncleboo]

Haven't had time to research it, but, didn't Islandtrader put some in his 21'?

[abl1111]

I originally cut the back cap off years ago, at the hawse holes, to access rotted transom and to convert from twin i/o to single. Glassed it back and thru bolted the entire topside to hull joint ) not sure if that encompasses the liner too ? ).

Funny you mention the rod holders. I removed these years ago for more room and just recently have thought about how they were as support. I might re-install them to test. I'm sure it adds support, but I'm looking for solid support as my new hardtop is making the gunnel flex due to windage and wave action. At first I thought it was the hardtop design, but I'm pretty sure it's the gunnel's flexibility ( When I stand on the gunnel and jump up and down on it, it flexes enough for the hardtop to shimmy ).

I think adding a few knees under the gunnels will tighten things up. But, I'm not familiar with this at all, and don't want to add any pressure points and want to do it right ( thinks like; does it get glassed on all three sides or do you leave space, can you glass to the liner, or should you cut through the liner and glass directly to the hull )

[bigeasy1]

How bad are they flexing?,and is the core rotted? I think You may have some rotted core issues form what you say about the wiggle.

On my Tsunami I run Down riggers with 20lb weights,off booms that are extended about 5' feet out.
They are mounted on the port & starboard gunnels just ahead of the hawse pipe openings for the ropes.
They put a big strain on the gunnels,and when I first mounted the riggers, I could see the flex on them,when the booms were extended and the weights were bouncing like they would be when running the riggers,especially when it's rough.
I figured I had to fix it somehow.

If this helps any,
I removed some of the rotted core on the gunnels,(from the bottom,Ugh) )and replaced it with marine ply,and a few layers of 1708.I had some fairly heavy woven roving hanging around,so I laid up some of that on top of the 1708. I re-cored and beefed up sections on each side running from the stern foward to just short of where the taper from the window ends.

It made a substantial difference,and cut the flex down considerably with all that stess from the riggers and weights hanging 5' off the sides.
I was a b-tch however laying on my back to remove and replace the rotted core.I don't want to ever do it again.

[Old'sCool]

I replaced rotted wood on my 23' with 1" Starboard.

[Sullivan21]

Originally Posted by Old'sCool

I replaced rotted wood on my 23' with 1" Starboard.

Yes look at what Old'sCool did, I will be adding the same thing, I know what you mean, I have a bit of "shutter" that i will be attending to this winter.

[bigeasy1]

abl1111

I didn't see your last reply,as I got taken away from my computer,so my reply was before you mentioned the hardtop.
I'd like to see the hardtop,as I may be doing that conversion at some point.
Do you have any pictures?
Btw,after I recored the gunnels,I can now hang from my arch (I'm 240lbs),and there is no movement or flex t all