Chopping Mortices

[lowell holmes]

The common practice when marking the limits of a mortise is to match your mortice gage to the width of the chisel. Then when chopping the mortise, the chisel will remove the wood to the mark of the mortice gage. This is the technique I have used.

Santa left two Ray Iles mortise chisels on my bench a 1/4" and a 3/8". Instructions included with the chisel say that it is better to mark the width of the mortice a bit wider than the chisel, maybe 1/16". After chopping the mortise, clean up the side walls of the mortise with a wide bench chisel.

My question is, do any of you use the Ray Iles technique? You could certainly keep the walls lof the mortisce straight and vertical.

OBTW, I am really impressed with the chisels. Paul Sellers said they are the best chisels he has ever used. Of course, the English tend to stick together. :)

[steven c newman]

Actually, the marking gauge I have has only a single point. I lay out the mortise using the already made tenon. The marking gauge is then used to mark (re-mark) the layout lines. Yep, I do clean up the sides with a wide chisel. Maybe I'm doing things "bass-ackwards" here? Just that once I have the tenon the way I want, I can then use the tenon itself to layout the mortise, no measuring required. I'll even take a "sharpie" and mark on the chisel how deep to make the mortise, by using the tenon as a guide.

[Terry Beadle]

I do not mark the mortise 1/16th wider than the chisel. That defeats the purpose of the shape and control of the chisel. A mortise chisel uses it's side edges to control the angle of the mortise as precisely as hand held tools will allow, and IMO that's a very good bit of control.

I practice getting the 90 degree control right and depend on the side of the chisel to follow that goal. If you can, take a look at David Charlesworth's video on using chisels for precision jointery. IMO it's worth it's weight in wood shaving sweat. He does take things to a bit extreme but the techniques he demonstrates gives many clues to success.

I make the mortise first and fit the tennon. Shoulder planes make this a precision and happy method.

Enjoy the shavings !

[John Coloccia]

If I where going to make a rough mortise and then pare back the sides to a line, it would be FAR easier to simply drill out most of the waste and then pare to the line. It makes no sense to me to use a mortising chisel to do that.

[Casey Gooding]

I think that method might work for those just beginning with hand tools. It allows a larger margin of error than the typical approach.

[lowell holmes]

Well,

My marking gage is a copy of the Benjamin Seaton Tool Chest gage with two pins set at exactly the chisel width. I'll most likely stay with that.

I think I will experiment with the Maynard technique as described by Christopher Schwarz in the Spring 2007 Woodworking Magazine.

The pigsticker chisels will excavate the mortise quicker than any other method. I am a bit skeptical of marking the mortise a bit wide, so I posted to find if anyone used that technique.

Out of respect for Ray Iles,the skill he used in designing and making the chisels, I will experiment with it. I just wonderd if any in this forum use it.

Thanks for responding.

[Jim Koepke]

Lowell,

I think this is like the debate about cutting tails or pins first.

What works for you to make a strong joint is the right way.

As long as it is realized what follows is just my opinion and they are not the musings of an expert, then they can be taken with the grain of salt they deserve.

First, the marking gauge is set to the width of the chisel's edge. Then the mortice is laid out. Then the mortice is chopped a little deeper than the tenon is going to be. The setting on the gauge for the mortice is used to lay out the tenon. Then the tenon is cut and if needed adjusted to fit the mortice.

jtk

[lowell holmes]

Jim,

Your way is the way I learned at Homstead Heritage while making a Crafstman Style Rocker, some 44 m&t joints. It is the way I have done it since.

I'm not planning on changing, but when Ray Iles recommends something different, I am inclined to evaluate it. I am curious if anyone on this forum has tried his technique. It certainly insures straight, vertical walls of the mortise.

My trial mortices with the new chisels certainly were easy and I wouldn't hesitate to use them as they are.

The Maynard technique I spoke of earlier is one where he drills a hole in the mortice with a brace bit and then chisels the mortice. The depth of the hole establishes the depth and provides a space for the chips to go as they are levered out.

My other mortice chisels are what used to be called sash chisels, and while they are really high quality, they don't work as easily as the new ones.

The Iles chisels are like the ones Frank Klausz talks about in his video.

[Pam Niedermayer]

Your way is the way I learned at Homstead Heritage while making a Crafstman Style Rocker, some 44 m&t joints. It is the way I have done it since....

I made that rocker at Homestead, too, lots of tiny mortises, great fun. BTW, I don't much like all these fiddly methods, either. Measure, even if twice, and cut once. Any other approach leads to more trimming events and thus misfitting.

Pam

[Matthew Hills]

So for those who use mortises straight off the mortising chisel, how smooth are your sidewalls? is it smooth enough to provide a lot of surface area for a glued joint, or is it still a bit rough, providing a mixture of mechanical support and a bit of glued joint?

Matt

[lowell holmes]

Some fit and are good.

Sometimes a bit of mortise clean up is necessary, accompanied by a bit of veneer on the tenon.

Frank Klausz talks about it on his tape. "Making Mortise and Tenon Joints".

[Pam Niedermayer]

So for those who use mortises straight off the mortising chisel, how smooth are your sidewalls? is it smooth enough to provide a lot of surface area for a glued joint, or is it still a bit rough, providing a mixture of mechanical support and a bit of glued joint?

Smooth enough; but it's a result of a combination of techniques. I use Japanese mortise chisels mostly, and they're designed to cut smooth mortises (the backs are very slightly wider than the fronts and have very sharp arrises) without levering at all, I have other small chisels for cleaning out any stray fibers. Also, I cut mortises in the order shown below (copied from Jeff Gorman's site, bottom of page, http://www.amgron.clara.net/maynardmortise40.html):

[Kirk Poore]

So for those who use mortises straight off the mortising chisel, how smooth are your sidewalls? is it smooth enough to provide a lot of surface area for a glued joint, or is it still a bit rough, providing a mixture of mechanical support and a bit of glued joint?

Matt

I make the mortise as wide as the chisel, and, unless I screw up and get a little twist or left/right tilt in the chisel, my sides come out pretty smooth. Now, the first fifty or a hundred mortises I chopped came out on the rough side fairly often.

Terry's comment is correct. Mortising chisels have square sides so that you can keep them straight, and that only works when the sides are right against mortise sides.

Kirk

[lowell holmes]

My Lie Nielsen chisels are rectangular as you state.

The Ray Iles chisels are trapezoidal. The small side of the trapezoid is very small. You probably will not see it unless you are looking for it.

Frank Klausz is a proponent of this design.

I think I will like the Iles more.

Some times I chop a mortise with a bench chisel if I don't have a proper mortise chisel. The mortises for 1" square through tenon are examples.

[Pam Niedermayer]

... Some times I chop a mortise with a bench chisel if I don't have a proper mortise chisel. The mortises for 1" square through tenon are examples.

One could argue that 1" holes aren't mortises except in timber framing, which explains why there aren't any 1" mortise chisels.

Pam

[John Coloccia]

So for those who use mortises straight off the mortising chisel, how smooth are your sidewalls? is it smooth enough to provide a lot of surface area for a glued joint, or is it still a bit rough, providing a mixture of mechanical support and a bit of glued joint?

Matt

Depending on the wood, I would get a mixture of both back when I was mortising by hand. For example, in another thread we were talking about the different kinds of mahoganies. I get all sorts of ugly when I'm working Khaya (African Mahogany) but it saws well and as long as it's dimensionally sound, the joint is OK even though the mating surfaces may be a bit rough. My thought was always that all the strength should come from the M&T fit, and the glue should really just be keeping the joint from falling apart. A draw bored M&T operates on this principle and though many people glue them, glue is simply not necessary as the pin's only purpose is to keep the joint tight, and the strength comes from a tight fit at the shoulders and cheeks. A loose fit there combined with the strongest glue on the planet will eventually loosen up and wiggle free one day. I'm not an expert. That's just my opinion.

Loose tenons ala' Domino are very strong, but I wonder what they'll be like in 20 years compared to a standard M&T or a draw bored M&T. I'm not suggesting they will be weaker. It would be an interesting test if someone feels like making, say, 100 M&T and loose tenon joints, and then testing 5 of them to destruction every year for the next 20 years to see how they all hold up with time.

[lowell holmes]

I agree.

1/2" is the largest mortise chisel I've seen.

They didn't have mortise chisels at Homstead Heritage when I was there.

[Pam Niedermayer]

Not when I was there either; but I took my own tools. Actually, as much as I appreciated their classes, they're very inconvenient when dealing with those of us who already knew handtool woodworking before getting there; so unless I took their beginning classes, which I would not, I wasn't allowed to take their advanced classes. I had to do the rocking chair class as an individual tutorial.

I was impressed with how tough those Marples were, handled one 1/4" mortise after another with applomb.

Pam

[lowell holmes]

Since this post, I have found that Japan Woodworker has mortise chisels up to 1" size.

[Pam Niedermayer]

Since this post, I have found that Japan Woodworker has mortise chisels up to 1" size.

Yeah, well...

Pam