Thread: 30 second mortise -with hand tools challenge

Originally Posted by MartinCH

Notes on this method.

1- Prefer square mortises and a will align the ham knife with the ends meet the mortise. The makes it easier to clean up the ends.
2- If refinement is required, a bevel down chisel cleans up the base quickly
3- I have made Ham knifes (cheese chisels) from $3 craftwright scraper. In a short length these can take the hammering
4 - there are "leather knifes" available from the usual suspects on the internet that look similar to my ham knife.

Martin, what (dry) timbers have you tried in on?

Regards from Perth

Derek

Dry Timbers that I have used with this approach
Jarrah
Tasmanian Oak
Sheoak
Blackwood
Pine a couple of varieties minus radio for sure and another type unidentified
Spotted gum
MDF

The holes at either end "mostly' block splitting.

I have some smaller "ham knifes" made from craftright scrapers that are thinner if splitting is a concern.
Also sometimes I don't hammer to full depth. The short level can be "planed" down with chisel. Slower but easy.

I have gone across grain using this approach but spacing between holes needs to be closer. Also, working on the endgrain side of hole, needs a bit of care, but is workable. nest to hammer between the holes on the side of mortise furthest from the edge first.




There is second technique I use as well but I will likely spin up a seperate thread.
The second technique is easier to dive down deep and works in end grain, enabling floating tenons. Takes tad more cleaning up than this one. This techniques is easier to judge depth of the mortise.

Thought I would add - I have never used these tools a "green" wood tool. After starting using the approach, as it is pretty simple and I assumed someone had used the approach before. Twybil was what was found that is, in principle, similar. They're likely others using this style as well, but I don't know of them as yet.

Hi All

Photos of the sequence. In this case the timber factored between the two holes, when ham knife was hammered in. Didn't obtain the full depth that that allows the use of the bolt to fracture out a lump.
With a bevel down chisel I planed out 5 / 6mm deep layers the hammer in again. Not quite as rapid but easier than than chopping through the end grain.


IMG_5667.jpgIMG_5668.jpgIMG_5671.jpgIMG_5673 2.jpgIMG_5674 2.jpg

Martin, I think this is brilliant!

I need a closer look at the ham knife - side, end. Length, thickness?

Regards from Perth

Derek

Derek, It looks a lot like your kerfing chisel.... doing a similar job along the grain?

Hi Derek

The Ham Knife / Cheese chisel has double bevel edge. It 30mm wide and the body tapers from 0.9 to 2mm.
Have a second tool that is 13mm 0.9mm thick, square at the leading edge and can penetrate about 18mm deep.
Ideally, would shape the bodies a differently, to ease deep penetration, improve accuracy. At some stage need make one 8/9mm wide for smaller details - but as they are, these work.


Notes on other uses -(they are sort of a bulk wood removal tool)
- stopped ends on dado's
- stopped ends on rebates (note for one project, took out a rectangular blocks from the side of the timber- that felt "odd" as as typically that wood is disintegrated)
- waste between dovetail - (needs a narrow version but is is possible to punch though end grain)

and mortises of course.

Not currently regarding them as a "precision" tool - traditional designs are better for the final 0.X mm and the bodies are not "perfected"
Once in rhythm, work proceeds easily with these tools and I guess they save the edges of my chisels for precise work

Originally Posted by MartinCH

I will to bet that hobbiest's sometimes don't even finish what they started.

Yes to the rest but. Isn't being a hobbyist just that... Someone that doesn't finish anything. LOL.

Come to think of it... That was the rule years ago for professionals also. Mechanics drove junkers, carpenters house was never finished... My house still needs skirting a year after I put the carpets down, and I have a couple furniture pieces - in pieces.

Well, the proof's in the pudding, as they say. Being able to knock out the chunk of she-oak like that is pretty impressive. Your WA she-oak is a bit softer than the east-coast variety (A, torulosa) but still a hard, fissile wood. I do wonder though, if a 'blunt' end might not work even better. Might be worth some experimentation.

Looks like we all need an ultra-thin, short bladed chisel or two - Veritas, take note....

Cheers,

Ian,

The Ham knife had an edge at the start. It's also realitively strong as body tapers from 0.9 to 2mm accoss 50mm. Curved front helps as well - T think
Used the knife in spotted gum, Tasmanian Blackwood and jarrah, Tasmanian oak, mdf.

Tried blunt edges as well. They work but without the taper and perhaps heavier hammering snapped them when longer than approx 15 to 18mm.

Regards