How long does it take for an experienced woodworker to chop out a mortice

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

tibi

Established Member
Joined
27 Nov 2020
Messages
588
Reaction score
227
Location
Slovakia
Hello,

I am now restoring my great grandfather's workbench. Here is the picture in the original condition.

IMG_0039.jpg


I have burnt the original legs in the fireplace, as they were too low (the bench was only 75 cm high) and they were unstable (eaten by the worms, as the boards on the floor and up holding the bench were made of pine or fir).

I am now making a new set of legs from beech and I have kept the original oak tusk tenons, which were in good condition, so I just want to reuse them. I need to cut 60x30 - 40 mm deep mortices for the original tusk tenon stretchers.

I have first scribed with the knife perpendicular lines across the mortice approximately 3 - 5 mm apart where the chisel will go for chopping. It helps me prevent twisting of the bench chisel (I do not have mortice chisels) and position the chisel perpendicular to the mortice walls. I have used a 12 mm chisel to make 1/2 of the mortice depth on the left side, the same on the right side and I was left with 6 mm bridge in the center that was cleared afterward. Then I did the same thing from the other side of the board so I got a thorough mortice and finally, I cleaned the sides. So for one 30 mm wide and 60 mm long, 40 mm deep through mortice, I cut 4 x 12x60 mm x 20 mm mortices and then cleared 6x60 mm bridges in the center. The whole procedure took me around 45 minutes per one through mortice. I did not want to use a brace, as the chisel tends to twist more when clearing the walls.

I need to make 4 through mortices for this bench and I am also building another beech bench from scratch, where I will need another 4 mortices (you can see the wood for it in the picture)

My question is how long should It take for an experienced worker to chop out mortice of this size without using a brace? I just want to figure out if, on average, it takes so long for everyone or I can do it in 1/2 or 1/3 time once I get more skill.

Thank you.
 

Orraloon

Established Member
Joined
18 Oct 2016
Messages
1,046
Reaction score
489
Location
Blue mountains Australia
For a mortice that size I would have drilled out the bulk then cleaned up the sides with chisels but then I am a lazy kind of woodworker. Hand chopping a mortice needs a chisel the width of the mortice and you set your gauge against the chisel to mark it out the joint.

Chopping a Mortise by Hand - YouTube
Thats fine for small and medium joints and my largest mortice chisel is 19mm. I do have a couple of big old framing firmers up to 1&1/2'' and I have had a go a couple of times at large ones on benches and bed builds but I soon found it easier to reach for the forstner bits when things get large.
Regards
John
 

bourbon

Established Member
Joined
3 Jun 2014
Messages
774
Reaction score
215
Location
Lichfield Staffordshire
It takes as long as it takes. If it's not a paying job, Then why put yourself under time pressure? Some people will knock it out in 5 minutes, some a lot longer.
 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
22,931
Reaction score
2,789
Location
Derbyshire
If chisel only - very big mortices and similar holes easier if the sides are chopped out with a thin mortice chisel (1/8") first, then the ends chopped from each side with wider chisels. Most of the waste then comes out as a single block.
Surprisingly quick but I'm not going to volunteer a time trial!
There's a knack with a mortice chisel - you often read about levering etc but in fact it's easier if you keep the chisel vertical at all times and chop down the face of the previous cut, leaving the chippings to take care of themselves. In other words emulate the action of the hand powered mortice machine.
 
Last edited:

tibi

Established Member
Joined
27 Nov 2020
Messages
588
Reaction score
227
Location
Slovakia
If chisel only - very big mortices and similar holes easier if the sides are chopped out with a thin mortice chisel (1/8") first, then the ends chopped from each side with wider chisels. Most of the waste then comes out as a single block.
Surprisingly quick but I'm not going to volunteer a time trial!
Thanks Jacob, I used the same technique, but I have used 1/2" chisels for the sides.
 
Joined
5 Nov 2020
Messages
563
Reaction score
517
Location
Ireland
Yep sounds about right to me. It'd probably take me longer, actually. There's a reason why pros use power tools! :) And I don't know if you're stopping to sharpen your chisels...
 

tibi

Established Member
Joined
27 Nov 2020
Messages
588
Reaction score
227
Location
Slovakia
For a mortice that size I would have drilled out the bulk then cleaned up the sides with chisels but then I am a lazy kind of woodworker. Hand chopping a mortice needs a chisel the width of the mortice and you set your gauge against the chisel to mark it out the joint.

Chopping a Mortise by Hand - YouTube
Thats fine for small and medium joints and my largest mortice chisel is 19mm. I do have a couple of big old framing firmers up to 1&1/2'' and I have had a go a couple of times at large ones on benches and bed builds but I soon found it easier to reach for the forstner bits when things get large.
Regards
John
For a mortice that size I would have drilled out the bulk then cleaned up the sides with chisels but then I am a lazy kind of woodworker. Hand chopping a mortice needs a chisel the width of the mortice and you set your gauge against the chisel to mark it out the joint.

Chopping a Mortise by Hand - YouTube
Thats fine for small and medium joints and my largest mortice chisel is 19mm. I do have a couple of big old framing firmers up to 1&1/2'' and I have had a go a couple of times at large ones on benches and bed builds but I soon found it easier to reach for the forstner bits when things get large.
Regards
John
I have two mortices to go, so I may try the brace and bit alternative as well and compare the results. I have a chisel that is 1 mm wider than the mortice, and tenons are already done, as I am reusing the old tusk tenons from the workbench. That is why I opted for double mortice and remove the center way.
 

Orraloon

Established Member
Joined
18 Oct 2016
Messages
1,046
Reaction score
489
Location
Blue mountains Australia
At the end of the day its whatever gets the job done. It has only just dawned on me what you were describing in the first post. I was just thinking 30mm wide. Anyhow does not hurt to have a few ways to skin the cat.
Regards
John
 

tibi

Established Member
Joined
27 Nov 2020
Messages
588
Reaction score
227
Location
Slovakia
Yep sounds about right to me. It'd probably take me longer, actually. There's a reason why pros use power tools! :) And I don't know if you're stopping to sharpen your chisels...
I only strop during one mortice. I sharpen when I move to the next mortice.
 

DBC

Established Member
Joined
6 Mar 2015
Messages
183
Reaction score
281
Location
Essex
To cut a mortise fast start cutting it shortly before 5 on Friday afternoon. For some reason this always makes me pick up the pace on whatever I’m doing.
 

tibi

Established Member
Joined
27 Nov 2020
Messages
588
Reaction score
227
Location
Slovakia
To cut a mortise fast start cutting it shortly before 5 on Friday afternoon. For some reason this always makes me pick up the pace on whatever I’m doing.
The issue with this approach is that when you look at it on Monday morning and you say: Should have I taken more time .....
 
Joined
5 Nov 2020
Messages
563
Reaction score
517
Location
Ireland
To cut a mortise fast start cutting it shortly before 5 on Friday afternoon. For some reason this always makes me pick up the pace on whatever I’m doing.

This is me all the way through 5 years of vocational school; and it's amazing how hard it is to get those bad habits out 40 years later...
 
Top