What's the best way to neatly cut a wooden cube in half, removing little material?

Question

I'm in the process of making some wooden block tubing clamps, a bit like these or the one at the bottom of this page.

The blocks are fine, the leather hinge is all sorted and I'm not worried about boring the holes. I am hesitant about the best way of cutting the blocks in half as cleanly as possible and without removing too much material. I do have the use of a bandsaw, but don't have much faith that the blade won't meander.

Is a bandsaw the recommended solution, or would it be less risky to use a hand tool, such as this:

Answer 1

I am hesitant about the best way of cutting the blocks in half as cleanly as possible and without removing too much material.

Let me present a slightly different tack here.

Looking at the first link you posted, it looks very much like the blocks are an exact fit on the tubes:

This is actually pretty simple to achieve. First, cut two blocks that are each half of a cube. Then, clamp the blocks together and drill the hole for the tube such that half of the hole is on half of each piece. This is best done on a drill press.

Like @rob states, you might want the kerf taken out anyway so that you get some clamping action on the blocks. If that's the case, then either of the answers posted by @rob or @keshlam will work perfectly fine.

Edit #1: If you want the clamping action while still following my original advise, shim between the blocks with some thick paper or card stock or thin shims of wood. It will essentially be the same as taking the kerf out with a saw.

Answer 2

If you have access to a table saw an easy way to get clean cuts and perfect cubes might be:

1. Cut precise half cubes on table saw.
2. Clamp half cubes together then bore your holes.

Same goes for other types of saws. Although a table saw will give you a nice quick, clean cut, a properly tuned band saw with a fence (even just clamp some scrap to your band saw table as a guide to ride the block against) will do the job just fine. A table saw might not even be an option depending on how thick your blocks are.

That said, as rob notes in his answer you still probably want to remove material to improve clamping action on the pipes. If you use the above method you could insert a thin (1/32" or so) spacer between the half cubes before clamping and drilling, or sand them down after drilling.

Answer 3

Yes, a hand saw--especially a Japanese-style saw like the kataba in your picture--will give you a thinner kerf than, say, a table saw. This saw cuts on the pull stroke rather than the push stroke like Western-style hand saws, but even a hand saw with a thick plate and large amount of set on the teeth will cut a thinner kerf than most, if not all, table saw blades.

You should be able to either tune your bandsaw to cut straight, or you can learn and adjust for the drift. That said, in this case I would say it's ok if your bandsaw blade wanders a little bit, since the two pieces will still have perfectly-mating surfaces.

Another point worth mentioning is that you don't necessarily have to worry about cutting a very small kerf. In the image from the second link you shared, there does appear to be a fairly significant space between the two sides of the block from the larger kerf. A larger kerf will allow you to clamp more tightly around the pipe, especially if the drilled hole as-is does not provide a snug fit.

Answer 4

Either a bandsaw or a thin-bladed handsaw should do the job. For handsaws, Western backsaw or Eastern pull-style saw generally have the thinnest blades you can find easily.

Even a thin-kerf tablesaw blade might do the job, depending on just how critical it is to avoid waste.

Answer 5

You do not need to cut a block in half at all. You just need to make sure the that the two halves mate to each other well, which is more a matter of grinding/sanding than sawing.

I would make the half-blocks by using a table saw and then make two square faces using a pair of disc sanders. Then, I would clamp them together with a kant clamp and sand the remaining faces. A band saw is the wrong tool.

You want to have 2 disc sanders because one should be fitted with a roughing abrasive like 100 grit, and the other should have a fine abrasive like a 400 grit. Alternatively you can do the production in batches, first roughing all the blocks and then fine sanding them, using the same sander.