Dove Tail chisels

[Frederick Skelly]

Derek you ask good questions.

The side bevels are 20 degrees, enough to clear the corner of the steepest typical DT angles. The primary bevel at the cutting edge is 25 degrees with a secondary honed bevel at 30 degrees. I find this a good combination for paring and chopping. Having control of the heat treating process allows me to tweak the tempering to produce favorable characteristics for the chisel's intended purpose. These are tempered at a slightly higher temperature than say a chisel meant for paring. That helps them hold up to chopping. When I test these I should be able to pare cleanly, then chop a base line and still go back and pare cleanly. If it passes this test I know I have the heat treating spot on. There is little to no land on the sides of these chisels. Once surface ground I typically have to break the edges with a piece of fine abrasive so as to make them safe to hold. The thickness is a nominal 1/8" but I make these from oversize stock so once ground they are typically .135 to .138 finished thickness.

The size came about when I was doing a lot of dovetailing on a couple projects. Even though I cut some nice joinery on those projects I did notice that there was a tendency for my edge to walk slightly out of the knife line when I changed my focus to the striking point at the top of the chisel handle. The longer chisels have a higher center of gravity. The small size lowers the center of gravity and puts the knife line and the top of the handle in one line of sight so there is no need to change your focus when striking the top. This is evidently a common issue because these have proved to be one of the most popular chisels I offer.

The way dovetailing is taught these days there is a lot of emphasis on efficient methods to excavate waste. Bashing out a lot of waste with a chisel wears out three things. The person doing the work, the handle of the chisel and most importantly the edge. If more efficient waste excavation is your method then a large chisel with a bigger handle is no longer a necessity. I much prefer to save my sharp chisel edges for the important work of cutting cleanly to the knife lines.

Ron

I really enjoy learning the thinking behind a tool's design. Thanks for the lesson Ron!

[Derek Cohen]

Thanks Ron. All that sounds very good to me. Shorter blades have more control (think Japanese oire nomi). I especially like the blades at 1/8". That's a great balance. Most I see are 3/16", and that gets heavy in the wider chisels (3/4" and up).

Regards from Perth

Derek

[Charles Guest]

People knife the woodworking equivalent of the Marianas Trench for a baseline, with a double-beveled knife, and then wonder why there's a gap there.

[Edwin Santos]

Derek you ask good questions.


The size came about when I was doing a lot of dovetailing on a couple projects. Even though I cut some nice joinery on those projects I did notice that there was a tendency for my edge to walk slightly out of the knife line when I changed my focus to the striking point at the top of the chisel handle. The longer chisels have a higher center of gravity. The small size lowers the center of gravity and puts the knife line and the top of the handle in one line of sight so there is no need to change your focus when striking the top. This is evidently a common issue because these have proved to be one of the most popular chisels I offer.

The way dovetailing is taught these days there is a lot of emphasis on efficient methods to excavate waste. Bashing out a lot of waste with a chisel wears out three things. The person doing the work, the handle of the chisel and most importantly the edge. If more efficient waste excavation is your method then a large chisel with a bigger handle is no longer a necessity. I much prefer to save my sharp chisel edges for the important work of cutting cleanly to the knife lines.

Ron

I have reached a similar conclusion on what you're saying about chisel size.
Ashley Iles makes a shorter chisel called the American Pattern Butt chisel. They have very narrow lands, and I have come to love them because when doing fine work, I tend to choke up on the chisel and grip with my fingers very close to the cutting edge (as opposed to wrapping my hand around the handle). The shorter size and lower center of gravity make a big difference. I think the size and form factor of your chisels is very similar.

I might point out when paring, the opposite is the case, and I tend to reach for a standard size bench chisel, so I don't want to suggest the shorter size is an all purpose solution.

Some of this is very subjective so it all depends on how the craftsperson works and the type of work he or she is doing.

[Frederick Skelly]

People knife the woodworking equivalent of the Marianas Trench for a baseline, with a double-beveled knife, and then wonder why there's a gap there.

I fall into that trap at times. So what's your technique Charles?

[Derek Cohen]

It is not whether a knife is single- or double bevelled, but the angle the line is struck, and how wide is the tip of the knife.

I use a double bevelled Stanley craft knife mostly, but the blade is tipped over, the bevel is low, and light-medium pressure is the order of the day.

Regards from Perth

Derek

[Tom Bender]

A double beveled knife can certainly work well especially in very skilled hands, but a single bevel is more likely to be sharpened consistently. It is easier to know the angle against the chisel wall and it makes less demands on my skill and vision.

[Derek Cohen]

For most scribing I use the Stanley knife in the centre. It is double-bevelled, and angling it for a cut is simple (once one is used to doing so). The two others, by Swann-Morton, are similar.



For dovetails, I use one I designed and now built by Chris Vesper. This can be held flush against the socket wall, which is needed in skinny tails …



Regards from Perth

Derek