Fixing a bent frame

I am just about finished with the interior glassing of my Skerry, and I'm starting on assembling and installing the seats and centerboard box.

The sides of the centerboard box are pieces like this:

The notches fit into an oval cutout in the boat's center frame.

My problem is that the center frame is bent. I think I somehow constructed my boat slightly too narrow. The breasthooks needed to be sanded to be slightly narrower, and now this.

The specific problem is that the top of the frame bends away from the centerboard box, so if the box is firmly on the bottom of the boat, it doesn't reach its contact point on the frame. Or if it touches that contact point, then the box isn't touching the bottom of the boat.

I can think of two ways to fix this: 1) somehow straighten the frame, and 2) shape the box (as I did with the breasthooks). CLC support recommends #1.

What do the wise men here recommend, #1 or #2? Or something else I haven't thought of? If #1, then how do I do the straightening? Bungee cords? Straps? Trying to figure out how to position the boat in my work area, and fix the straps or cords to something stationary, keep the boat in place, etc.


7 replies:

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RE: Fixing a bent frame

Is that frame part actually warped? Or is it being "bent" from being put under stress once fitted to your hull because the hull's sides are too close together?

What does CLC tell you the width between top edges of sheer strakes ought to be before the frame is installed?

I've used a 'reversed' pipe clamp to good effect to push things into the position desired but in your case, if you do that, it's likely the frame will bow once the clamp is released. (Lacking a pipe clamp you can use two sticks, cut to the desired total inside length, then 'lever' them in pushing against one another... but that's still not a permanent solution.

Another possibility is putting a temporary stringer "stiffener" on the frame up near the top edge to help resist the squeeze of the sheer strakes. You'd need to be able to remove that stiffener though so plan accordingly

Adding a frame "cap" would help, something to stiffen the otherwise unsupported edge of the plywood, not unlike what I've seen referred to as a doubler, on one or both sides.

RE: Fixing a bent frame

None of the three frames shown in the Skerry construction gallery look like what you've pictured, unless you've cropped off the 'ears' that bear againts the top strakes.

Too, farther along in construction, each frame is bonded to a panel that serves as a deck or seat, which in your case would serve well to hold the warped frame in proper shape as well as stiffening the entire structure.

Sometimes a builder has to get creative in figuring out ways to bring the various parts into their proper alignment before being bonded together. You have to be the judge for what's 'close enough' vs unacceptable when it comes to your own project.

In the end a frame warped a little ought not seriously compromise the sturdiness of your build but if you can find then implement a fix before you go further you'll feel more comfortable for the doing!

RE: Fixing a bent frame

I think the frame is bent by the hull of the boat being too narrow, not the frame itself being warped.  The frames go in before the 1st, 2nd, and 3rd panels, so if the frames were squeezed, it was by my wiring things too tightly (and then gluing).

If I understand what you mean by "ear", it is present in the picture, but its edge is facing the camera dead on, so that it is difficult to see. Look for the dark vertical line to the left of the jigsaw joint.

I do want to fix this problem before I go further, and I'm looking for ideas. I am pessimistic that bending the frame back into shape is likely to be successful. It is a thin piece of plywood (weakened further by the oval cutout), and obviously there are large forces squeezing. Which is why I'm wondering about adjusting the centerboard box. But I'd have to do that without modifying the angle of the centerboard slot, and without impeding the centerboard itself.

What about making the bottom notch a bit wider? That would allow the box to slide forward so that the top notch makes contact with the bent frame.

This is my first CLC project, and also my first project remotely like this. I am all for getting a working boat even if it doesn't look pretty.  (That ship sailed a long time ago. No pun intended.) My family thinks that instead of painting to cover up my errors, just go with a bright finish, since the wood looks so good. As for the imperfections that will be visible: Scars that I've earned.


RE: Fixing a bent frame

I've used the temporary stiffener along the top on my boats where I've had this problem. A 1x2 piece of dimensional lumber screwed in place with drywall screws would probably work, but with the 1" side screwed to the frame to get maximum stiffness.

Since the seat will cover the frame and the trunk, you could leave the stiffeners in place. Just make them be a permanent part of the boat. Instead of only screwing them in place, screw and glue them and remove the screws and plug the holes. Use a continuous piece of wood for the side without the trunkc and 2 pieces on the trunk side. They'll also give extra gluing area for the seat. And once the trunk is in place, it will also work to keep the frame straight.


As spclark says, you may need something to open out the hull while you're straightening the frame. If not the reverse pipe clamp, then just a piece of wood to spread it will do.

Good luck,




RE: Fixing a bent frame

I wuz gonna reply when I read your last post G but my coffee was ready and I needed it.


So Laszlo got his in before me, said (*almost) everything I was gonna.

You're doing a fine job, just keep in mind there are things you'll confront that have no explanation in the build manual. That's why this forum exists I suppose.

I'd concentrate on making sure the daggerboard trunk assembly fits properly against the bottom. That part IS important as to how it fits and how it's positioned.

As for the *bent frame? It's got a big cutout innit, so not really too structural (be thicker if it had to be, or a doubler added) yet it does serve to keep daggerboard trunk square to the hull bottom. Once that seat piece is bonded, if the bend is still there it won't show. You might even be able to add some temporary blocking along the back edge of that seat piece to force the frame into a straight line during the seat-bonding operation. Then the blocks could come off, or not, unless they protrude out beyond the seat's back edge.

Slightly bent frame won't affect hull performance, it'll be reinforced vertically in the center by the d'board trunk and at the top by the seat panel spanning the interior from side to side. A mis-positioned daggerboard trunk could, to some degree.

RE: Fixing a bent frame

Have you tried dry fitting the seat atop the bent frame?  Whether it fits at all, or how much you have to force things to get it to fit, might determine what you need to do next.  For example, if you can get the seat to drop into place by pushing the top of the frame back in line, then maybe the best thing to do is to clamp a temporary stiffener onto the top part of the frame so that it will meet the daggerboard case correctly.  Once the case and frame are well and truly glued together, remove the stiffener and proceed from there.

Worth a try, methinks.


RE: Fixing a bent frame

   If you can still mount the daggerboard case square and straight, on the centerline, within a small distance of the intended fore/aft position, I'd think about just making up any gaps between the case with a shim and fillet grade epoxy.  Maybe even just bed it in epoxy between the center bulkhead and the end of the case.  Use measurements, square and level the case dry, estimate how much gap there may be, trowel on that and a bit extra epoxy and bed the whole thing down.  don't pull it down tight with screws unless you have solid shims.  The screws are really there mostly to hold the whole thing together until the epoxy cures.  If you have already glued and glassed that bulkhead I'd avoid trying to remove it or move it.  too many things to go wrong.

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