Thread: Should a 12mm wide mortise be chopped with a 12mm mortise chisel?

Hi Russell

Short answer: yes.

Mark out the lines and then chop out. Less work. Less likelihood for error.

If you wish, you can increase the accuracy by marking/scribing the lines deeply, then paring out the top few mm.





Link: http://www.inthewoodshop.com/Furnitu...ndMortice.html

I am reminded of the article in the latest AWR on dovetailing (only glanced at it so I am open to correction). It looked like the author sawed about 1 or 2 mm from the lines, then pared away the waste. That is not a good method. Develop your sawing skills.

In morticing, practice your chopping skills. And there are a number of ways to chop mortices and saw tenon cheeks. The above is just one.

Regards from Perth

Derek

Cheers, Derek

Originally Posted by Russell Cook

Hi,

My question is as the title of the thread. It may sound like a silly question, but it seems to me that using a chisel as wide as the mortise leaves very little room for error. If instead you use a 10mm mortise chisel to cut a 12mm mortise, you could afford a bit of inaccuracy.

Any tips?

I do both, but banging out a mortise that is the same size as the mortise chisel is much faster but I have less control of the finish on bottom (not really important unless you have a reason to say a fox tail wedged mortise and tenon).

I am reminded of the article in the latest AWR on dovetailing (only glanced at it so I am open to correction). It looked like the author sawed about 1 or 2 mm from the lines, then pared away the waste. That is not a good method. Develop your sawing skills.

In morticing, practice your chopping skills. And there are a number of ways to chop mortices and saw tenon cheeks. The above is just one.

Regards from Perth

Derek[/QUOTE]


You wouldn't care to name that person?




Cheers,




Frank.

Chopping a mortise with the correct technique allows you to end up with parallel sides. Start widening them and it's a damn sight harder to keep them parallel.

Originally Posted by Russell Cook

Hi,

My question is as the title of the thread. It may sound like a silly question, but it seems to me that using a chisel as wide as the mortise leaves very little room for error. If instead you use a 10mm mortise chisel to cut a 12mm mortise, you could afford a bit of inaccuracy.

Any tips?

the short answer "yes" was on the money.

i sense some trepidation, dont worry its not heart surgery on your mother, wife or child, its a bit of timber, if you stuff it up you can start again but even if your joint is on the slack side you can fix it one way or another and along the way you have learnt something


cheers
chippy

Originally Posted by ch!ppy

the short answer "yes" was on the money.

i sense some trepidation, dont worry its not heart surgery on your mother, wife or child, its a bit of timber, if you stuff it up you can start again but even if your joint is on the slack side you can fix it one way or another and along the way you have learnt something


cheers
chippy

Absolutely. It is only wood. The worst that can happen is that you start again and acquire a little firewood. Just about any accident/error can be corrected. For example, a mortice that is off centre can be straightened by paring it wider (using a fence that you clamp on). You can build up the cheeks of the tenon to fit. If you doubt your ability here, then cut the tenon after the mortice. That way you can always saw it slightly wider.

Chippy wrote of trepidation. A good description. We all felt that - I still do - when it comes to making these cuts. We all need to develop a "go for it" attitude: saw to the line and chop to the mark. That is how we develop our skills. I make my share of errors - but I have learned to cover them up well.

Russel, use aids to guide you as you go. Eventually you can put them aside as you develop muscle memory. For example, stand a square alongside the chisel so that you can judge vertical.

I think that the important part is marking out accurately, and seeing the marks! Working to the lines is then easy!

Regards from Perth

Derek

Cheers for the encouragement, gents.

I'm using a book as my teacher so it's great to have you guys help me when something's unclear.

Maybe I'll be able to return the favor in the future if you have any questions about Chinese tools!

Originally Posted by derekcohen

Russel, use aids to guide you as you go. Eventually you can put them aside as you develop muscle memory. For example, stand a square alongside the chisel so that you can judge vertical.

I think that the important part is marking out accurately, and seeing the marks! Working to the lines is then easy!

Regards from Perth

Derek

Russel, I am very much a novice but I fully endorse Derek's suggestion. I use a miniature set square to align a mortise chisel - it must be vertical in all directions! Also the chisel must be scary sharp - a blunt tool will always wander.

Fair Winds

Graeme

Well I was taught and have always used the right/same sized chisel that the tenon will be. I don't ever recall having an issue with the alignment of the mortise. In my apprenticeship I hand cut 100's of mortise and tenon joints.