Thread: what's the best wood joint for this application?

Small timber, 40mm square - the easiest would be butt jointing/screwing, stronger/better - stub mortise and tenon I would think.... what is the application? how much load is the joint going to have to take?

or dowel joints work. I would go stub M&T for preference.

Are you gluing the joint or is it straight joinery?

I started making this chair, and planned on having simple wood arm rests. Now I realize that I cut the mortises which connect the arm rest to the chair back/back leg, is too low. I've been brainstorming and the idea I am considering, is to a make a frame on the arm rest to house a thick piece of foam which will sit inside it. Since I already bought 9 CM thick foam for the chair cushion, I'm thinking about using that also for the armrests. I know it might be kind of strange to have that thick of foam on an armrest, but I can't figure a better way to raise it higher.

The frame for the arm rest pad will have a groove in it to slide a piece of quarter inch thick wood as a bottom similar to how you do in a drawer. This base will have velcro, and so will the bottom of the cushion according to my plan.


Attachment 165912

Attachment 165913

Fill the mortise in with some of the same wood trying to match the grain if you have any left then cut the mortise again.

I wouldn't call it easy, but haunched M&T joints are the strongest, especially if you bevel the ends of the tenons so they meet in the middle of the joint. Fill the joint with epoxy, if suitable for the wood.

You could also try pocket hole joinery, although they're not as strong.

I wasn't quite sure if there was a better way to do it than mortise and tenon joints into the upright. Because there isn't room for a long tenon, and that one side is unsupported I was a little worried about the strength but can't think of a better way to do it. I guess the mortises could be on the rail.

In the back of my mind I remember seeing some other joints doing this, but I can't find any of that information. And I having a feeling that some of them are complicated, and maybe not much stronger if at all, than M&T joints would be.

Jumping on Enak's bandwagon, you could relocate the arms to where you want them and them fit a decorative "brace" under the join long enough to cover the old mortise..........

Originally Posted by Chief Tiff

I wouldn't call it easy, but haunched M&T joints are the strongest, especially if you bevel the ends of the tenons so they meet in the middle of the joint. Fill the joint with epoxy, if suitable for the wood.

You could also try pocket hole joinery, although they're not as strong.

I think I'll try that maybe. Thanks.

Originally Posted by enak

Fill the mortise in with some of the same wood trying to match the grain if you have any left then cut the mortise again.

That's probably what I should do. It's funny how I hadn't thought of that. But now I have some strange compulsion to follow through with the thick pad idea. I figure I already put so much thought into it, and it might be more comfortable anyways, might as well give it a shot. As long as I don't end up breaking it.

Here is a picture of what I'm working with.

Yeah often I fixate on one idea and miss the easy and perhaps better options, also saves lots of time and hair tearing

Here are a few joint types I'm considering.

Hi,

I think the sketches would work. It depends on how much end grain you want to tolerate in the finished piece. A lot of display cabinets use three way joints like what you are trying to do. The high end stuff generally uses a three way mitre joint so that no end grain is exposed. This shows how to do it but it looks pretty fiddly.

Simplified Three-Way Miter - Fine Woodworking PDF Cover Page

I think you have to sign up for a 14 day free trial to get at the article though.

Your sketches are probably just as effective though.

Cheers