Thread: This is not really working — or Derek, please help

Hi Ian

When you use the shoulder plane (nice one!) to trim each side, are you working to a mark?

I would knife a line all around the tenon, and plane to the line.

I would trim the short ends with a chisel.

When aiming for absolute precision, I knife a sharp, clean line on all sides, then undercut it to form a fence. This is used to guide the saw.

Hope this helps.

Regards from Perth

Derek

Originally Posted by derekcohen

Hi Ian

When you use the shoulder plane (nice one!) to trim each side, are you working to a mark?

I would knife a line all around the tenon, and plane to the line.

I would trim the short ends with a chisel.

When aiming for absolute precision, I knife a sharp, clean line on all sides, then undercut it to form a fence. This is used to guide the saw.

Hope this helps.

Regards from Perth

Derek

Derek, hi

Thanks for the prompt reply

I knifed the layout lines (I marked all the way round the stretcher and the lines met) but cut well on the waste side (I was in a hurry so used a bandsaw rather than a carsass saw)
I shaped the tenons by chiselling down the end grain

I've used the plane to shave down to the knife lines (supporting the end grain with the fence on my shooting board)
but when I fit the stretcher to the leg, there's about a 1/2mm gap on one side which I've tried to correct by taking a little more off the "high" side (the stretchers are deliberately a little long so I have about 1–1.5mm of adjustment)

maybe the leg is not square?
is there a relatively easy fix if it's not? unfortunately the table is partly assembled so re-squaring the leg is not an option.


ian

Hi Ian

It would not be possible to have your layout lines meet if your stretcher was not square (assuming you are marking square to each face).

How thick are your lines? Going over on one side and under on the other could amount to .5mm - I mark very thin lines with a sharp knife.

My other thought is whether your tenon faces are parallel to the stretcher - since you are running the shoulder plane on them, if they are not parallel, then you will be planing at an angle.

Regards from Perth

Derek

Just a suggestion - how about drawboring the tenons in? It closes up the gaps that I'm not good enough to shave off and can provide a nice feature.

My guess is the mortice is not cut square to the leg face & is drawing the tennon in at a slight angle.

Hi Ian

It's the morning so my brain is less dead.

Johnno makes a good point. Check it out.

But my money is on that the mortice is not deep enough at some point, and this is not allowing the tenon to seat squarely.

Interesting checklist for fault-finding we have developed ..

Regards from Perth

Derek

Sorry Derek, I'm staying with my diagnosis. If the mortice was not deep enough, both shoulders would be proud. With an opening of only .5mm one side I'd say the mortice is not true to the face...not an easy task with hand tools, but one that should be quite easy to see. Clamp the leg on the bench with the apron pointing straight up. You will be quite surprised at how accurate the eye can be if the rail has entered the leg off plumb.
Tennon could also be out of square & is not as easy to measure I find.

Also not sure drawboring the tennon would close it up. More likely to cause a bit of damage.
If the piece is important to you Ian, find out what went wrong & start again.

It is possible to accidently make the tenon no longer square off the rail. The effect is the same as John'o describes, just the other half of the cause sometimes. I find in the classes I have done that when a tenon is over cut fat and brought down, it is a "common" thing to end up with an angled tenon.

About the only way I have been able to judge whether a tenon is angled (when I don't it that way) is to lay a thick rule on the face over hanging the tenon. Like John'o says, the eye can determine a lot. Hold the rail so that you can view the surface of the tenon and see if it is parallel to the rule. Do the same on the other side. Even though the tenon is short, you may be able to judge its being parallel to the face of the rail when it is difficult to measure.

Make sure to mark around a rail for a tenon by only one edge. Mark the edge the square will be used against. Then use the square on that edge line to mark across the show face and across the back face. Connect the lines on the face across the other edge. Do they now meet up?

Take care, Mike

Thanks everyone.

some things to check when I get back to the project on Sunday



ian

Thanks every one for your input

My problem was a combination of off square tenon and the face of the legs not being exactly parallel to each other

WIP photo – the "problem" joints have the band clamp.


ian

Thanks again everyone for your input

here is the finished table – it's my Mother in law's Christmas gift


ian

Nice little shaker(?) table Ian. Recipient should be very happy.