Sunday, July 29, 2007

Fixing Frames

Along the way I had about four frame parts that needed recutting, so this weekend, since the weather cooperated, I recut them.

I have a batten of plywood that I cut with the jigsaw, this is exactly the width of the distance between the side of the jigsaw base and the blade. By lining this up with my cut line, and clamping a guide beside it...

I can then run the jigsaw along this guide and get a perfect cut every time. This has the benefit that the entire base of the jigsaw is supported for the cut. Using the Jig I use to use... Old JigSaw Guide only one side was supported, and cuts were not always square.

One thing to bear in mind while you are congratulating yourself on a perfect cut, is that a Bosch Jigsaw is powerful enough to cut through the bench as well as the oak, and you won't notice it slowing down, or working any harder. If it can slash through 1" White Oak, then an extra half inch of Black and Decker workbench is nothing.

Tuesday, July 24, 2007

Some Snaps

Just a quick snap of the foremost frame, and some of the concertina shavings that suggest that its getting to be time to touch up the edge.

The layout board is the 3 ply plywood that I had bought in the local builders providers. I had to find some use for it.

Once you have the lines drawn out on a board, it becomes a lot easier to make sure things line up just so.

Monday, July 23, 2007

Rain, Interspersed with Heavy Showers and Occasional Drizzle.

I had great plans for this weekend. I long list of things that I was planning on doing. The weather had other plans. This summer has really not been suited to outdoor boatbuilding. It's been best suited to getting on a plane and going somewhere else.

I did get some work done, I had to plane a simple Oak batten to fit between two plywood gussets, The slats for the seats will screw into these battens. Given that I had gone to the trouble of buying some decent blades for my planes and some waterstones and then going to the trouble of reading all about sharpening, I thought I'd leave the Bosch in its box and break out the Stanley.

The blade was sharp, bald patch on my arm sharp. Gillete eat your heart out. I set the plane to take very thin shavings and started. I had to take about 3/16 of an inch off the batten to make it fit, and I had to square it up a little.

Damn, It's hard work. Oak is hard stuff, and I had the "benefit" of trying to do this on a fold up work bench, so I had to use my weight to hold the bench steady and my arms to plane. I gather that with a proper bench you get to use your body weight to do the planing.

I found that Oak will blunt a blade quite quickly, you can feel it getting harder and harder to push the plane, and you find the shavings concertina. This is a good indication that 30 seconds on the waterstone is required, sacrifice some more hair from my arm to the Sharp Gods, and off we go again.

It was a great experience to square and thickness the wood the old fashioned way, but I will admit to dragging out the Bosch in order do the second batten, in about 1/10th of the time.

When you look at pictures of old wooden sailing ships, and think that they didn't have Bosch, Makita, or even Black and Decker, you start to look at them in a different light.

Oh yes, and never try a crushing handshake on someone who actaully uses a hand tools for a living.

Thursday, July 12, 2007

A centerboard case.

Having a lifting keel or centerboard in a small sail boat seems like a wonderful idea. A nice deep fin for beating upwind, and a nice shallow draft for coming in to shore. And it makes trailering easier.

Of course there's the whole problem of the big hole that you make in the bottom of the boat to allow you to lower and raise the keel.

The design calls for a centerboard case which passes through a slot in the oak keel, and there are two oak bedlogs (planks) either side of the box which sit on the keel.

That would be fine if the keel were flat, but the 5/4th thick oak keel is actually curved. The bedlogs have to match perfectly, or the centerboard case will leak like a Government Department. And they have to be aligned so that the trunk case sits vertically upright.

To make matters more interesting, the ends of the centerboard case need to butt up perfectly to the frames - So I need to build the centerboard case before I bend the oak keel over the frames, but I need to bend the oak keel to find the shape for the bed logs.....

- Here's the plan.

I'll build the CenterBoard case with the logs just tacked in place with a screw or two. I'll shift the logs away from the keel so that they only touch the keel at the frames. I'll also just screw the Case to the frames that it buts against.

Then when I've bent the keel into place, I can trace the curve of the keel, cut them, take the case out and complete the assembly and replace it. Glue and screw the whole lot togehter and I'm sorted.

What do you think ?


There's plywood, and there's marine plywood and there's Marine Plywood.

The local builders providers sells marine ply. Excellent. Less than half the price of the stuff sold by Waller Wickham. What's not to like.

Well - specifically, there's only 3 plys on the 6mm boards. And the veneer ply is as thin as paint, leaving a big fat ply in the middle with all it's strength along one axis. Not likely to hold up to much of anything.

So I bit the bullet and wandered down to Waller Wickham and got a sheet of 5 ply 6mm to make up the gussets and the centerboard case. I believe the ply they stock is Robbins Elite.

Who was it that said "Light, strong, cheap, pick any two". This stuff is light, strong, well made, but not cheap.

I didn't feel as though I even had a decision to make though, the builders yard marine ply was totally inadequate, even though it was stamped with BS1088.