Compass planes

Compass planes

I’ve been testing curves for back slats recently. That’s meant a lot of time with my compass plane making bending forms. That plane is a chatterbox. It’s in its nature. There are so many light, movable parts only partially attached to each other that it’s a wonder the thing can stay quiet at all.

Roughing in the curve with spokeshaves

Most plane makers go to great lengths to make their tools out of heavy, solid lumps of stuff. It keeps the chatter to a minimum. Compass planes are not built the same way.

The handles on my straight spokeshave show a lot more wear than on the round-bottomed tool. You can get quite a lot of curve before you need the curved sole.
Cambered iron

But there are things you can do. Starting with low expectations helps!

I used to think of my Record 020 as a jack plane. I expected it to do a lot of work quite quickly and give me a decent result. These days I see it more like a jointer plane. I use it for the last few shavings to get the final shape. The curve comes from a bandsaw, jigsaw or bowsaw followed by spokeshaves. They are my jack planes for curves.

As with all edge tools start with the sharpest iron you can hone. It won’t solve everything but at least you’ll know that’s not one of the issues. Grind and hone it like a jointer plane iron – with a small camber. Rather than trying to take a full width shaving I work the high spots and check for square frequently. I don’t expect to get beautiful long ribbons from end to end. Given that we’re making a curve the grain direction will change at some point and these things don’t go up hill!

The mouth and bed aren’t flush. Not ideal but it works.

If you’ve got a sharp, cambered iron, lightly set, you’re cutting downhill and you’re still getting chatter there are a couple of things worth investigating. The mouth of the plane is a magnet for resin. It builds up and needs to be scraped out. There’s little you can do about the step between the mouth and the frog. The frog has no fore and aft adjustment. I’ve tried shimming it with mylar and sheets of tin foil. Not worth the effort. Make sure that the cap iron fits well and the lever cap is tight.

With the mouth clean have a look at the peened pins that hold the frog to the sole. With the sole set for a concave curve these can stick out and catch. You won’t notice it when planing but it can’t help the chatter. You can sand the sole much as you might lap a smoothing plane. I didn’t notice a lot of difference but it can’t hurt.

And finally, with the plane perfectly set up a squiggle of wax on that rather rough sole makes the world of difference.

Not the most satisfying shavings but it’s the curve we’re interested in
Advertisements
Round and round…

Round and round…

On a chair leg’s journey from square to round (for the pedants: from cuboidal to cylindrical) there are several options for marking it out to get to octagonal. I’m a big fan of the spar gauge; they’re handy for any piece that tapers along its length. But for building the occasional chair a dedicated tool may be a bit much.

Here’s another way – one that I use a lot even though I have a couple of spar gauges in a draw.

  • Plane the future chair leg square to a hair shy of the final diameter.
  • On one the end of the workpiece mark the centre using the 45 degree fence on your combination square.  
  • Draw a circle (or just a quarter of a circle) with a pair of compasses.
  • Mark a tangent using your combination square.
  • Set your marking gauge to the point where the tangent meets the edge.
  • Use this setting to mark the length of the workpiece.
  • Set the leg in joiner’s saddles and plane until the marks just disappear
  • Draw a line on all eight sides.
  • Plane a few strokes until your piece is an even 16 sides. No need to gauge anything here – trust your eye and the length of the ever decreasing pencil lines.
  • Scrape with a concave scraper.
  • Sand in a saddle
  • Repeat until fade…

Or you could use a lathe.











Repeat until fade…

The Slick

The Slick

NB: This post will contain no puns. It’s an exercise in self-control.

The renaissance in chairmaking has breathed new life into the drawknife. I’ve got two and use them a lot. But I’ve been neglecting my slick. It’s a beast of tool, more suited to timber framing or big boats. Every once in a while I find an excuse to use it just to stay in practice. And because it’s so much fun.

It’s capable of hogging off great ribbons of wood. Catch the grain in the wrong direction and you can do a lot of damage very quickly. In the video you’ll notice I’m very cautious at the start; I’m testing the grain direction. There are a couple of knots and I want to know what I can get away with.

I use two hand positions. For big movements both hands are on the handle. I keep the edge at an angle and simply push it along the bevel.

For finer work I wrap my left hand around the side of the blade and use my finger as a fence. This gives me more control and I can make finer cuts.

There are diminishing returns as I get closer to the lines. It quickly stops being worth taking smaller cuts with the slick and I turn to a heavily set jack plane.

Endgrain is less fun but still possible.

Several companies are making drawknives. Is anyone manufacturing slicks?