Hi,

I saw the program on the Arts & Crafts chair and was very interested because I have a pending project to put tenons through a through mortise, also on a curved piece of wood.

What I didn't see on the show and is very important to my project is how to make sure the mortises will be plumb and not follow the angle of the curved surface. This is to ensure the legs go square to the floor. I'm assuming the tenons were cut with a chisel, so was some kind of jig used to align the back of the chisel?

Put me on the list of big fans of the show.

Regards,
Blair
Toronto, Canada

Might be over thinking the angle a little bit. It seems to me that the bottom would be most critical since I think the shoulder creates a lot of strength. I would start from there and just eyeball the angle of the front and back of the mortise. Trust your eye and maybe set a bevel Gage up to sight on. Trust your eyes they are much accurate than you think. The human eye is very good at comparison.

Do a test mortise in a block to check this out. I think you will like what you get. If you need a little more guidance, go with a paring block cut to the correct bevel to guide the chisel back.

Steve

That is one of the reasons I draw a full scale plan. The ability to place a bevel gauge on the plan and get the angle avoids any use of trying to find the exact degree setting, and of course math errors.

I enjoyed the chair program as well. It almost makes me want to make something arts and crafts.

Thanks, All. I like the idea about the full size plan, that is certainly doable in this situation.
I chuckled over the incomplete desire to do Arts and Crafts. I concur, the part that scares me most is ammoniating the wood.

Fuming the wood is not a huge deal.

BUT safety, safety, safety. Make an outside plactic booth, fairly air tight as you want those ammonia fumes rolling all around the wood and staying put.

Secondly the commercial ammonia you want to use is highly caustic, wear a respirator for that type of fume, a full face mask, long sleeves and a good pair of rubber gloves.

Granted this booth needs to be in a safe place well away from foot traffic and especially kids.

But good planning and safety can yield a good result.

That being said I would think Radioactive would have a very good alternative to the caustic method.

Your Thoughts Radio???

I'm taking your question as: how do you make sure the mortises are parallel to each other, rather than perpendicular to the surface of the arm?

We kept things simple. First, we assembled the sides first, so we knew the legs were straight. Then, we set the arms on the shoulders of the legs and traced the tenons onto the edge of the arm. We then squared the lines across to where our tenons would be. This method gave us reliable lines on the top AND bottom of each arm. We drilled by hand to clear out most of the waste, then just worked to our lines from both sides. Once we got close, it was just a matter of careful fitting.

For me, this is a case where confidence in hand tools is invaluable. It may not be the fastest way, but I'm comfortable just drilling and chopping to get the fit. Another helpful skill is determining what matters. On this joint, the show face is almost the only thing. There is a large shoulder underneath which both supports the arm and hides gaps. While straight, plumb walls are ideal, a little undercutting and bruised shoulders don't bother me.

Thanks for the question and thanks for watching!
Eli

Thanks, Eli, I understood what you were saying, and should be able to apply this to my project. My challenge will be drilling and trimming through 2" of wood, but, as you say, only the show side is important.

Best regards,
Blair