Chisel technique

[Jim Dunn]

I think I've figured it out but I thought I'd ask just to be sure.

I am placing some false thru tenons in the top of a small cabinet I am making and am, or was, having trouble with my chisel technique. I first roughed the width with a router:eek::rolleyes: ( a non hand tool for your primitive types:D) and am squaring the ends using a marking tool to define the width and length of the mortise. I have found that the concept of chiseling on the mark line compresses the fibers of the wood making the end of the mortise look slightly dovetailed.

I then found that if I sneak up on the mark, taking slight cuts, that the compression was minimal.

The end cuts were easy as even if the wood compressed a little I could just lengthen the tenon. Also it seemed that the end grain didn't as easily compress.

I hope that the above is explainitory enough to get the idea what I am doing and what I have discovered. I think this is the correct way to finish and define mortises.

The chisels are sharp as I am not having any trouble cutting the end grain fibers in hard maple.

If anybody has any other technique that is easier or more of a traditional way of doing what I am trying to accomplish please chime in.

Thanks--------------Jim:)

[glenn bradley]

Sounds like you've got it. If the chisel is crushing fibers instead of cutting them, it is generally too big of a bite.

[Gary Herrmann]

Jim, if your chisels are sharp - and you're not removing much meat, you can just pare the wood away - you don't even need a mallet.

[Sam Yerardi]

Glenn & Gary are right. I'll add the following. I assume you're using a bevel-edge chisel. It's a little harder to keep the mortise square with a bevel-edge chisel. I use one a lot for that but I usually use a mortising chisel. A mortising chisel inherently keeps the mortise square. Also, the approach you are taking is correct. You typically start in the middle of the mortise and successively work your way towards either end. How you get there is different among some woodworkers but I start by making a stab cut straight down in the middle, and then chop away at it, reversing the chisel with each cut (beveled edge towards the middle each time). The problem with starting at an end is you tend to use the edge of the mortise as a fulcrum in making your cuts, and this starts crushing & dogging up the ends. One of the hardest things for in learning to use chisels in accurate work is PATIENCE. I tend to work fast but this is an area where slower is always a good thing (unless you're doing it for a living ;)).

[Jim Dunn]

Sam and all thanks for the reply's.

Sam I am in fact using Japanese type chisels. But I'm only going 1/2" deep as these are false tenons. Purely decorative not thru. That said I am slightly under cutting the ends and sides of the mortices so that the top/surface is on the line and everything below that is beveled away/wider. That way I don't have to worry them being square to get a good fit.

I had read, I think on this forum, about someone doing the same thing. Made sense to me and I thought why not give it a try. They failed to mention, or I failed to observe, the sneaking up on the mark with the chisel.

I'm not doing this for a living but as it's for my LOML it will make my living easier:)

[Marcus Ward]

Cutting end grain in maple can be done with a fairly dull chisel, try soft pine. If you can pare them off like you're peeling fruit, then it's sharp. I'd say if it's crushing fibers, you need to sharpen more.

[Jim Dunn]

I'd say if it's crushing fibers, you need to sharpen more.

Marcus it's only crushing fibers, that I can tell, because the pressure of the chisel is being equally displaced along the mark line. Paring straight down at the edge of the material I want to remove gives a clean cut and no wood distortion.

My chisels are sharp enough to shave with though, at least my arm hairs:eek:

[Marcus Ward]

Hmmmm... I dunno then, that's odd. How wide is the chisel?

[Jim Koepke]

Marcus it's only crushing fibers, that I can tell, because the pressure of the chisel is being equally displaced along the mark line. Paring straight down at the edge of the material I want to remove gives a clean cut and no wood distortion.

My chisels are sharp enough to shave with though, at least my arm hairs:eek:

I take a light cuts at the ends of the mortice with a square sided chisel and then, turn the chisel around and move it a little away toward the center of the mortice. Then a cut is taken with the chisel held at an angle toward the first cut to take out a little wedge of wood. After this is done at both ends, material between the cuts can be taken out with a paring chisel.

The end cuts can be worked on to the depth wanted before removing waste from the middle.

jim

[Jim Dunn]

Hmmmm... I dunno then, that's odd. How wide is the chisel?

Marcus then chisel is 1/16th" thick at the depth it goes into the wood with a light to moderate strike. Overall the chisel is 1/8" thick at the end of the bevel.

I might not be making myself clear about the fibers compressing. Seems to me that even though you have placed the cutting edge on the mark line and strike straight down the force of the blow drives the chisel down and away from the beveled back. That compresses the fiber on the straight side of the chisel. The same thing happens on the back side of the chisel but as all that material is being parred away you don't have a reference line so it's not noticable.

I hope it's clear as mudd now:eek::p:)