The Arctic Tern Project

Volume 2 Issue No. 12 December 6, 2005

Roll Like an Egyptian

Well finally the big rollover event came and went, and went quite smoothly as well (thankfully!). Here’s how is all shook down.

Last time I wrote that I’d built the rolling frames and next needed to brace the boat inside them. This is what it looks like:

Rather than using brute force to roll the boat I decided to make these ramps and pull the boat up them.

The 2x4’s with holes in them are to brace the boat as it’s jacked up the ramp. I managed to get the boat up to 20 degrees by myself but wanted to wait for reinforcements to arrive before going any further. Note: All ramps and runners are rubbed with candle wax. This greatly reduces friction.

The crew arrives! In this photo Elias looks on as I explain the process.

In this photo you can see Adrian, Ken, and Quill.

Richard’s looking after the braces as I winch the boat up the ramp.

Once the boat is rotated 90 degrees we winch up the ramp again.

There’s Andrew and Elias and, in the photo on the right, Richard.

All the pulling was done with a come-a-long attached to the carport. Thankfully, I over-engineered my carport.

Job done! Thanks Dad for taking photos!

Thanks to everyone who came out and helped, including Hans who didn’t make it into any of the photos.

A Scarphing Jig

Last time I mentioned that I’d been spending a fair bit of time reconditioning a radial arm saw (RAS) that I found in the garbage and, after all the work, the motor had a meltdown. Well, it turns out the motor was unfixable so after a bit of cursing I got a buy-and-sell and started the hunt. I managed to find, not one, but two radial arm saws for an amazing price. One is a vintage DeWalt, the other is a like-new Craftsman. The Craftsman has a 10” blade that is just big enough to cut 8:1 scarphs in 12mm plywood. Here’s the jig I came up with and how to use it. If you’ve got a radial arm saw and you know how to set it up to cut precisely you can do some amazing stuff with it.

1. Set saw motor in vertical plane and behind fence of jig. Slide jig-stick in slot and set angle of saw blade to match jig-stick.

2. Set depth of cut by marker on jig-stick.

3. Set height of blade using scrap 12 mm on flat. Blade should just take off top lamination (1 mm).

4. Test out on some scrap. Actually, before cutting the bevel I ran the piece through the saw in “rip-mode” and scored a cut through the top lamination where the bevel will finish.

5. Admire the results. For full sheets of plywood I’ll need to rig up some roller extensions but I think it’ll work. When it comes time to scarph the sheets for the keel sides I’ll let you know how it goes!

The jig stick is laid out and cut before hand using very precise measurements. You can create one for each thickness of material you need to cut scarphs for.

Next Time

Hmm…Christmas season is here. Not much time for boat building I’m afraid. The next step is to lay out the keel measurements on the boat and to lay up laminations for the keel shoe, trailing-edge and leading edge.