Mortising a curved surface - How is it done?

[Glen Blanchard]

How would you go about the following mortising job if done with a router?

Let’s say I have long, curved legs that I will be putting on jewelry box, and for sake of argument let’s say the legs have the shape of a “wishbone”, with each vertical element of the wishbone being one leg. Now if I wanted to join these legs with a horizontal piece approx. 2/3 of the way down their length, via a loose tenon, I will need to cut mortises in each of the legs. How does one go about routing a mortise in this situation as there are no right angles with which to work?

[Doug Shepard]

Are the legs already shaped? If not, I'd put the mortises in first then cut the curves out.

[Glen Blanchard]

Are the legs already shaped? If not, I'd put the mortises in first then cut the curves out.

Thought of that possibilty. What if the curve is severe enough to make that approach impossible - that is, the depth of the initial mortise would have to be excesssive?

[Jon Eckels]

Build a jig that cradles the leg in such a way that it can be clamped in a stationary manner under a drill press and do it that way?

[Doug Shepard]

Thought of that possibilty. What if the curve is severe enough to make that approach impossible - that is, the depth of the initial mortise would have to be excesssive?

I guess I'm having trouble visualizing what you're doing. When I read loose tenon I guess I thought that would be at the top where the 'wishbone' joined. But re-reading your post it says 2/3rd down. Is this more of a stretcher between the two leg sections? A pic or sketch sure would help.

[Glen Blanchard]

I guess I'm having trouble visualizing what you're doing. When I read loose tenon I guess I thought that would be at the top where the 'wishbone' joined. But re-reading your post it says 2/3rd down. Is this more of a stretcher between the two leg sections? A pic or sketch sure would help.

Yes, a stretcher is exactly what I am talking about. I should have been more elaborate in my description. I will be routing a mortise at the top - where the two legs join - I've figured that out already - but it is the mortise I need at the stretcher that has me stumped.

There may not really be an answer to this, but I wanted to be sure I was not missing something obvious.

[John Young]

Instead of a mortise, could you just drill a hole? The stretcher could then be formed with a round tenon. It sounds like this would an ample joint for your application.

[Dave Richards]

Something like this? Are the curved parts sawn or laminated or steamed?

I think making a jig to hold the legs for mortising makes good sense. If the legs are laminated or steamed you could use create appropriate references on the clamping jig that would make it easy to locate the mortises.

[Glen Blanchard]

Something like this?

Yes, very much like this. The parts are sawn. I may have to consider a dowel placement.

[Mike Wenzloff]

I would either chop them by hand, or drill and pare them out. By the time the work holder is fashioned, you could already be gluing them together.

Many things we do, we create more work in preparing for the actual task than just using simple tools.

Take care, Mike

[Cliff Rohrabacher]

Build a jig that cradles the leg in such a way that it can be clamped in a stationary manner under a drill press and do it that way?

What he said.