I need measurements for bulkhead for a repair (?)

[DavidSW]

I'm making a repair to my scamp. I'm replacing sections of two side panels on the starboard side. I'm using West System manuals specifying how such plywood patches should be done.

Picture of the damage. I plan to put the new bulkhead in the middle between the exposed middle bulkhead and the visible bulkhead toward the back of the cutout. https://www.screencast.com/t/ehbfme8cs

Any comments, advice, or suggestions are welcomed. But here's my plan for the main challenge there:

The main challenge is reproducing the bend in short pieces of plywood.

I plan to mount an additional bulkhead in the middle of the repair, so that I can more accurately bend the replacement plywood. I first planned to measure the aft starboard bulkhead, and fashion a bulkhead that way. It would be easier, by a lot (I'm new at this) if I had the measurements or a drawing of it. Can anyone tell me the measurements, or supply a drawing, of just the aft starboard bulkhead?

Thanks in advance for that, if anyone can. And thanks for any advice, suggestions, etc.

[ram]

I don't have the specs for the bulkhead, and don't have the means to scan them off the plans. But I might suggest that rather than trying to bend one sheet of ply, you could consider using much thinner pieces (like 3mm) laminated together. These would bend quite easily to the curve of the hull in that section, and you could either use the hull itself as a form to lay them up in one piece or glue the first layer in place and then add layers to that. If you took this approach, you could avoid adding the extra bulkhead. If it were me, I'd put the first layer on the interior, oversized so it laps the edges of the damaged area. Then add layers on top of that with the edges scarfed a bit, each layer getting increasingly larger. That may seem like a lot of work, but when I look at the extent of the damage it would go pretty quickly and make a very sound repair to the hull.

[DavidSW]

Aha, thanks!
that's a great option to consider... Yeah I don't relish having the extra bulkhead, as it will take away from flexibility of storage in that locker. Ha, unfortunately I've already paid the piper to have the official 6mm plywood shipped, plus I'm in a big hurry to get back on the water. I have all the supplies ready for the "bend-the-6mm-ply" method. ... I'm keeping your plan in my journal; maybe I'll go back in during winter, remove the extra bulkhead, and do it in that way.

I've crafted a serviceable bulkhead by using cardboard first as a template. That's the only way to do it successfully, it turns out. Of course the proper size of the additional bulkhead differs slightly from the stock bulkheads fore and aft of it, since the dimensions of the boat are different. Heh, I didn't think about that.

So, I think with your answer, and since the exact measurements of any stock bulkhead would still require modification, I'll consider this problem solved.

[GregWads]

The hull planking thickness on the SCAMP is only 6mm ply, with 6oz fiberglass on the outside.

I believe I would go at it a bit differently. I would laminate 3 thicknesses of ply over the outside to get the shape of the outside of the hull. Maybe even add a board or something across the ouside of the laminations to keep the shape once the form is removed from the hull. The inside of your form is now the shape of your hull. Next laminate a couple of pieces of 3mm ply into your form. Make it oversized so you have enough material to cut the scarps on the new planking to match the scarps that you will have to cut on the hull so that the new planking will overlap the edges of the current planking. Glue on the new plank(s) then fiberglass over the patch.