Every so often I need a long reach clamp. Usually, the need arises when I have to hold something down on a work surface, for example. For these situations, a really strong clamp with a lot of clamping force is not always necessary.
A new project that I’m working on (a box joint jig) needs such a clamp to hold wider panels in place and that got me thinking about how I would make one.

Here’s what I came up with:

It has a 13″ deep throat and uses an oval shaped cam to apply clamping pressure, similar to a luthier clamp. It’s all wood, with no metal fasteners of any kind. The moving jaw (with the cam) locks onto the bar by jamming – the extra length makes this possible.

Since the end of the moving jaw that locks onto the bar will be under a lot of stress, I used finger joints:

to hold the end on. Extra strong and pretty cool looking.

Here it is in action:

This little project was as much an experiment as it was a useful tool. I wanted to see how well the moving jaw held when jammed on the bar and I was curious as to how easily the cam would operate and how much force it would be capable of exerting.

As far as clamps go, it’s not much of one – only able to apply a relatively small amount of clamping force. This is due mainly to the long jaws bending in opposition to the clamping force. It does have the strength needed for the purpose I built it for though.

The parts are fairly thick but in spit of this, they do bend when the clamp is used. I did consider adding a piece of 1/4″ threaded rod to the fixed jaw, along its inside length to put tension (this would counter the bending force) but didn’t bother, as it adequately does the job I needed it for without that.

There are some things that wood is not the best material for and this is one of them. If I were to build another long reach clamp, I’d do it with steel.