Boatbuilding Blog

July 12, 2008

Starting the Cabin

Filed under: Building - Cabin — tomlarkin @ 12:33 pm

I’m really happy to be building the cabin. It’s finally starting to look like the boat I’ve been imagining all these months.  I started assembling it last weekend and should finish by the end of this weekend (not including the roofs of course).  It’s a really interesting exercise in non-square angles and subtle oddities, while trying to keep everything symmetrical and esthetically pleasing. The main change to the plans is that the pilothouse is lengthened by 8 inches (see the mockup entry). To reduce the blank space at the aft end, I’m thinking of making the side windows 1 1/2 inches wider than the plan.  Building the mockup a couple of weeks ago really helped me. I have a fairly clear mental image of what I want it to look like.

It’s all 3/4 inch Oukoume, fastened to the deck structure with 3″ stainless screws on 4″ centers, as well as the full 4-layer glassing and fillet schedule I used on the bulkheads. Corners are fastened with 2 1/2 inch stainless screws 4 inches apart. The corners will be rounded and glassed. All edge joined panels are fastened with biscuits on 6 inch centers.

I’ve left off this one panel so I can climb in and out easily for a while.

View from the Port stern

I’ll post more pictures at the end of the weekend when there’s more progress.

Meanwhile I’m making a laminating jig for the cabin tops. They will be 3 layers of 1/4 inch ply. I’d really like to completely finish the inside before installing. Finishing overhead just doesn’t seem like it would be much fun.  There’s just some scrap in the jig picture below to see how it bends. I’m concerned about springback. I added 3/4 inch shims to the outsides so the laminated pieces will be curved more than they need to be on the assumption they will flatten out when removed from the mold. If they get flatter than the needed arch, I would have a very hard time getting them bent again. It should be easier to over-curve the pieces and ‘unbend’ them in place if necessary.  It’s going to have to be a trial and error process, with expensive materiel 🙂

Roof formin jig

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2 Comments »

  1. I don’t get it; why not just use 3/4 in. marine plywood sheets which, by definition, are already plys of material?

    Comment by Robert Wood — July 26, 2008 @ 8:54 am

  2. Thanks for reading Robert. Are you building or thinking of build ing a boat?

    Two reasons, I guess (and I really am guessing ;-)).

    3/4 inch ply seems too stiff to bend, even to that fairly minor curve. Bending just 2 layers of 1/4 inch ply was difficult. There was a lot of force to keep them bent. Even if I could bend the 3/4 inch sheet, that ‘unbending’ force would always be there, trying to pop the roof off or warp the cabin. Laminating the sheets should neutralize the force.

    And that’s what the designer suggested when I asked 🙂

    Comment by tomlarkin — July 26, 2008 @ 1:14 pm


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