Wood – How to cut out precise inside corners from hardboard

woodworking

We are making some templates out of 1/8" hardboard for some stonework and trying to get them accurate to within 1/32" and it is very tricky.

The hard parts are the inside corners (some of the templates have an L-shape). On the outside we can just use a rail saw to get a precise cut, but we can't do that with the inside corners. Using a jigsaw results in a jagged, uneven cut.

Best Answer

A couple ideas:

Try different jigsaw blades. Many different tooth configurations exist, and some will work better with fibrous material.
Use a circular saw set to full depth. The cut angle will be nearly 90°. Clamp guides to your workpiece if you don't feel steady. You can finish with a utility knife once you snap the remaining tip of the scrap, or overcut slightly on one face if that's not a problem.
Use a rotary tool and a jig.
Use your jigsaw, then clean up with a rotary tool and a straightedge (or just a utility knife).
Finish the cut with a very sharp chisel. The flat (non-beveled) side should be against your final piece.

Related Solutions

Wood – Good technique for squaring-up hardwood edges

You don't say what saw you used to cut the wood, but if you use a tenon saw you should get a cleaner cut in the first place that requires less sanding. This is because the saw has finer teeth for a smoother cut and a stiffening spine that means you get a straighter cut.

Clamping a second piece of wood to use as a guide is another alternative.

Alternatively you could use a plane to remove the excess wood - but make sure that you clamp a piece of scrap wood to the end of the plank to avoid it splitting:

------> direction of plane
+---------+---+
|         |   |
|    ^    |   | <- Scrap
|    |    |   |
|    |    |   |
  direction of grain

Wood – Does it make sense to try mounting the jigsaw onto the table

Could you do it... Yes. There are a few problems with this setup.

First, if the saw does not have a locking trigger how will you turn it on when you are cutting? If it does have a locking trigger, you'll want a way to turn the tool on/off quickly and easily. This could be achieved by connecting the saw to a power strip, and mounting the strip in an easily accessible area. You'd then use the switch on the power strip to turn the saw on/off.

Will mounting the saw make changing the blade difficult/impossible?

Mounting a jigsaw in this way could make it easier to force the wood, which could lead to binding, flexing, and even cause the blade to break (which could be deadly).

Lastly, why are you using a jigsaw for long straight cuts? Long straight cuts are far easier with a table/circular saw. The great thing about a jigsaw, is that the blade can bend and flex slightly. This makes cutting contours easier, but will make long straight cuts more difficult.

Best Answer

Related Solutions

Wood – Good technique for squaring-up hardwood edges

Wood – Does it make sense to try mounting the jigsaw onto the table

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