The adze is finally out of prototype phase and swinging into production. I've been delaying writing more about it until everything was finalized, which it finally is. I got a lot of great feedback about the tool at Woodworking in America, and Pete Galbert and I went back to the drawing board to make a few design tweaks that have really upped the performance of the tool, mostly the result of a subtle change to the curvature of the blade and the degree of external bevel. The first batch of twelve tools is in production, so I thought this would be a good time to provide a few more specifics about the adze.
The main structure of the tool is a steam bent hickory handle joined to an East Indian Rosewood head. The tenon on the end of the handle is tapered at the bottom of the joint, flared and double wedged from the top, and assembled with epoxy. It's like a chair joint on steroids; rugged, and it has to be to take the abuse this tool is subjected to.
|A batch of adze blades awaiting heat treatment with a couple of un-forged steel blanks.|
The blades are forged from 1/4" O1 tool steel, flared out at the cutting edge (1 3/4" from point to point after it is bent). The sweep of the edge is a two inch radius, enough curve to keep the corners from digging into the work and flat enough to be able to leave a surface that is relatively smooth and quick to clean up with the inshave or travisher. The blades are drilled and countersunk for a hex flathead machine screw that secures them to the rosewood head.
|An allen wrench loosens the blade.|
|Blade removed for grinding or sharpening.|
This adze is lighter than most adzes of European descent, closer in weight to the elbow adzes of the Pacific Northwest. Weight and balance of the tool was a major design consideration and one of the reasons for the mountain of adze prototypes that I made. I inserted weights into different portions of the head to experiment with the total weight of the tool and the amount of weight in front of and behind the handle. The final version has a thicker blade than my prototypes which eliminated the need for added weight. The thicker blade also gave the tool the forward balance that I knew I wanted as a result of my prototyping. Forward balance makes the tool track more intuitively in the cut and also puts all the weight right where the tool is working.
The action of the adze changes dramatically depending on where and how the handle is gripped. As a rule of thumb the closer to the head the handle is gripped, the more aggressively the tool will dig into the wood. The closer to the end of the handle the tool is gripped, the less the tool bites and the more easily it clears chips. Each user's sweet spot to hold the handle will be slightly different, corresponding to differences in forearm length, style of swing, height of work surface, and the desired cutting action. The red rubber band on the handle slides up and down and functions as a reference point for repeated hand placement. This is especially helpful when learning to use the adze. Does that rubber band look familiar to anyone?
|North Atlantic Lobster bands. Welcome to Maine.|
To use the adze most effectively, a relaxed grip is essential. This allows the tool to pivot in the hand at the end of the stroke, which helps to clear chips instead of digging, digging, digging in. There are times that you want to dig in, but that's another blog post. I start my grip by wrapping the thumb and index finger at the top edge of the band. I also wrap my middle finger around the tool, while my ring and pinky fingers remain relaxed.
The following pictures show how much this grip allows the tool to pivot in the hand.
|Adze pivoted back in the hand.|
Please note that the my wrist position is the same in both of these photos. The main portion of the swing comes from the elbow joint which generates power and provides gross movement of the adze along an arc. Imagine if the tool was gripped tightly and there was no movement in the wrist. In this scenario, the adze would only be able to cut along that one arc, with a radius originating at the elbow joint. Allowing the tool to pivot in the hand slightly allows the user to adjust the arc on which the tool is traveling to cut a wider or tighter curvature, as desired. Allowing the tool to pivot also seems to increase power. I'm going to have to do a video about this!
Roughing out a complex shape like a windsor chair seat requires several types of cuts with the adze and different grips for more power or control. I do plan to venture into video soon to better illustrate this and other techniques with the adze. More to come.