Get a spine!
This has been a busy week, hence the lack of blogging.
I still love school.
This week we got partners, and my buddy Kevin and I are now working on a little beetle cat together. Here she is as we got her. You can see where a previous owner went to the trouble to build a new stem and added on one plank on the port side, and then just stopped. Go figure.
You can see lots of rust damage from years of water getting through little cracks in the paint and destroying the iron fastenings.
So, the first order of business was to take off the deck and deck supports so that we could flip the boat upside down on top of molds that will hold the boat in the proper shape as we take it apart and re-assemble it with new bits. Here’s Kevin taking off the decking boards.
This is a view of the top edge of the sheer (top plank). With the decking removed, you can see where water infiltrated through the fastener holes and rusted out. I also think they used fasteners that were too large and didn’t predrill the holes so they split the planking where they fastened into it.
Deck all removed, and half of the centerboard trunk removed, revealing the centerboard (deep blue).
We set up the molds precisely on a grid that we’ve drawn on the floor, and then we brace the hell out of them. After all, we’re going to be plopping a boat on top of them, bending wood over them, and climbing on top of them. They need to be rock solid. Here’s Jason setting up his stations. These molds define the shape of the hull and we’ll be pulling the old boat down onto them to bring it back to original design shape.
And here’s our boat on the molds.
We screw the boat to the molds to hold it solidly, and then begin removing its spine: garboards, keel, stem, sternpost, and eventually the transom. Here’s Kevin taking out garboards (the planks that butt up against the keel).
You can see the cotton caulking that went in between the garboard and keel. The little light squares of wood act as washers to keep the screws from pulling through the plank when she screw it down to the molds.
Keel and stem removed.
Next, we fashion a new keel from 1 1/2″ oak and cut a rabbet (the slots you see on the left and right sides). We use a template to get the correct keel shape, and use a circular saw and hand planes to cut it out to the exact shape.
Then we put it in a steam box for an hour and a half (1 hr / inch thickness is the rule) to soften it up.
Then we clamp it to a long curved mold to give it the curve we want. Hot hot hot!!!
While that’s cooling down, we cut strips of mahogany, stack them up so that steam can get to all surfaces, and steam them as well.
When they come out of the steamer box, we bend them to shape on a form as well. Now, it’s starting to look like a new stem.
Once they’ve cooled and hold their shape, we epoxy them together in another form. This second form holds the laminates in the same shape as the first form, but laying the strips sideways on the table allows us to stack them more precisely. We’ve covered this bench with plastic, screwed in angle irons to the table along the edge of a pattern, and then we clamp the wet, glued layers up to the form. In a day we’ll take it off, clean up the glue and have ourselves a rough stem to work with.
We’re using mahogany for the stem rather than oak (original) because oak moves too much as it gets wet and dries. The result is that almost every beetle cat we get has delaminated stems. Mahogany is far more stable and will last much longer. For instance, here’s the original stem from this boat. It’s no surprise that the stem was one of the things the previous owner replaced.
And here’s the new keel clamped to the molds. This is what we’ll rebuild the boat around. The combination of stem, keel, and transom constitute the spine of a boat.
Not bad for a week’s work!
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