Some experiments in plane adjusting hammers

[Dave Anderson NH]

Here are some of my efforts in making hammers to adjust the irons and wedges in wooden planes. Brass hammers won't mushroom the ends of the plane irons and the wooden (lignum vitae) end of the heads won't chew up the wedges or leave divits on the heel of the planes. I made these because I wasn't happy with the few styles of plug ugly hammers commercially available. The heads are 360 brass with a lignum vitae cap over a small turned tenon opposite the brass striking face. The handles are white ash and are held in place with a black walnut wedge.

The brass was turned on a wood lathe with VERY sharp woodturning tools and the handles were rough shaped with a bandsaw and refined with a spokeshave. The first hammer (the prototype) is on the extreme right of the first photo and is barely acceptable in balance, handle shape, and performance. The one to the left of it was my next effort and came out well except for needing some work on the handle shape. My third hammer was absconded with by my son who dropped by a few weeks ago with my grandchildren and was less than subtle in expressing his desire for it. The three hammers on the left were assembled tonite and are each an experiment in shape and sport my new and improved handle design. The second photo is better at showing the newer handle shape. The new improved design is the one in the center. I always thought hammers were simple--- I was wrong. Shape, weight, balance, handle shape, and design are quite complex and this has become quite an education for me.

[Dave Anderson NH]

I got the order of the photos reversed. The text of my message refers to the hammer onthe extreme right of what is the second photo, not the first. I think I'll call it a nite now, my brain isn't connected to my typing fingers anymore.

[Lars Thomas]

As usual, great work. You continue to amaze me. Where did you pick up the brass stock?

No wine this time around??

[Bruce Page]

That is very nice work Dave. Are you using a form tool to generate the radiuses behind the head?

[Terry Quiram]

Dave

Great effort and I agree the redesigned handle looks a lot more comfortable to use. How long to turn the brass? How many times did you go to the grinder?

Terry

[Mike Schwing]

Dave, you are rapidly becoming one of my wood (and metal) working idols. Your work truly gives me inspiration.

[Dave Anderson NH]

The brass rod came from McMaster-Carr at $12.50 for a one foot length which yields 3 hammer heads. Brass is quite soft and is workable with standard woodturning tools. The tool rest must be placed very close to the workpiece and the tools have to be VERY sharp. Two trips to the grinder to resharpen for each head is about normal. I shaped the radius between the head and the body of the head with a spindle gouge and the small tenon which holds the lignum vitae head was done with a parting tool presented at an angle. The three tools used were a spindle gouge, a parting tool and the final shaping was blended with a skew. A second cut mill file is also useful for smoothing and blending the shape though you will need to keep your file card handy to get the brass out of the teeth. Sanding was to 600 grit and the heads were polished with a buffing wheel. Using a wood lathe is slow since you can't take too agressive a cut or you'll get catches. My best guess for time is an average of 3-4 hours per head.

Sorry about leaving the wine glass out of the picture. It was actually on the other end of the bench and contained Merlot for a change of pace.

[Marc Hills]

Dave,

Exquisite work, as usual. Didn't you at least reference the first of these hammers in your April bowsaw thread?

I've very curious about your comment about the prototype being barely acceptable in terms of balance. Given the delicacy required to adjust a wooden plane iron by hammer, I wager that hammer balance is the most important attribute (after material selection). On casual observation, there doesn't seem to be much difference between your hammers, but it almost looks like maybe your later versions had shorter heads and less material on the lignum vitae side of the head? Then again, the middle article in the second photograph seems to have a head that is noticeably *longer*.

Bottom line, I'm curious, but confused. What were you going for in terms of balance, and how did you change your design to acheive it?

[Dave Anderson NH]

The first three hammers were made this spring. In the photo with 5 hammers the two on the right are from the first batch. The third was confiscated by my son when he came up with the grandkids one nite. The rightmost hammer was the first made and is marginal. The second from the right is quite well balanced though the handle is a bit wimpy. Being one of those folks who has trouble leaving well enough alone, I wanted to experiment with different balance points and proportions. Some differences between the hammers are subtle, but mostly the angle of the photos makes the differences hard to see. Variation in the location of the eye of the head is one of the ways balance was modified, and the other method was to stretch the length of the lignum end up to almost half an inch. The most significant change other than balance between the first batch and the second is a reduction of the tenon diameter from 1/2" to 3/8". One of the lignum vitae pieces split in half along the grain line after some particularly hard whacks. I felt a thicker wall on the round mortise and a longer part overall would solve this problem. Time will tell.

I'm planning to bring all of the hammers to Shepherd tool when I go up there for the extravaganza of infill making in October. I figure 15 guys adjusting plane irons and using the hammers will give me a range of opinions. I suspect I'll get a variety of opinions based on individual preference, but in any case, I'll have a range of feedback.

[Marc Hills]

Thanks Dave:

Silly me, thinking about varying the amount of material on one side of head or another, and you come up with the overly complicated notion of moving the eye of the handle. Jeez! OK, if you want to do it *that* way! :)

(If we were children with a seesaw, I'd be the one trying to figure out how many rocks to load up on one side to even things out, while you'd just shift the fulcrum.)

Regarding the split wood end, did you consider either a ferrule for the lignum vitae or perhaps a leather washer around the shoulders of the brass tenon?

My curiosity stems not so much from an interest in making my own (I don't even have a lathe), but in trying to judge alternatives to my current plane hammer, which is a rubber mallet. Let's just say it's not a particularly subtle tool for such a precision task.

My one wedged-iron wood plane is an old coffin smoother. Learning to adjust it has been a very instructive lesson in the physical laws of momentum and inertia. Said rubber mallet hasn't made things easy though. There isn't a very good distinction between "not hard enough" and "way too much".

For the poor hand tool user on a very, very tight budget, what would you recommend for a more appropriate plane hammer? I'm only half-jokingly considering a cut down croquet mallet.

[Dave Anderson NH]

Hi Marc-

I hadn't considered a ferrule- I think it would look awkward. I didn't even think of a leather washer though it might be a good idea now that you've mentioned it. My main thought about better split resistance was that I might need to change the orientation of the cap so that the long grain is perpendicular to the axis of the head rather than in line with it as it is now. The long grain parallel is better looking, but I know the other option is far stronger.

I don't like the idea of a bouncy rubber mallet for adjusting a wedge or iron. Too much of the needed energy and control is absorbed by the rubber. One of the hammers with a hard plastic head might do it though. While they are not pretty, some brass hammers are available in industrial supply catalogs where non-sparking tools are shown. Lee Valley also makes a brassie but again I didn't like the style. An all wooden mallet of the right shape and size would be better than a rubber mallet to my way of thinking.

My goal was a hammer which was pleasing aesthtically, was durable, and had soft heads which wouldn't mushroom plane irons or torture the wedges. To get there, both heads needed to be crowned rather than flat. The end for adjusting the wedge and tapping the heel of the plane has to be small enough to get around tanged irons like those in molding planes which tend to extend above the wedge, and it also needs to be without edges which will leave dimples on the heel of the plane when loosening the wedge with a heel tap. The hammer needs to be small enough that it isn't too heavy or too awkward to handle with finesse. There are lots of options for materials in this set of requirements: heads of brass, bronze or bronze alloys, any strong dense hardwood, and even a paper or linen phenolic high pressure laminate- handles could be oak, ash, hickory, black locust, or horror of horrors even fiberglass.

My choices for materials were based on what I had at home (ash and lignum vitae), what was reasonably priced and readily machinable with my own shop tools (brass rod), and what would please my eyes when on the bench or on the shop wall.

[Marc Hills]

I think you're right, the ferrule would look awkward. Those are such beautiful tools David. You sure make it hard to even consider the commercial alternatives.

I really appreciate your comments on what makes an effective plane adjusting hammer. And I imagine you are right, after the Ultimate Neander Weekend in October, you'll have a lot more insight. Those hammers look like they'll nicely compliment all those beautiful Shepherd chariot and shoulder planes. Perhaps kitting your design is what Ben and Doug are looking for.

As always, thanks for answering my questions.

[Paul Barnard]

I hadn't considered a ferrule- I think it would look awkward.
Not if it was an integral part of the hammer body. It would be like a socket chisel then and no chance of the wood splitting.

By the way I used the handle of a screwdriver for a long time until a plane hammer arrived from Santa last Christmas. The screw driver had a metal ferrule to hit the iron and the wooden handle didn't mar the wood :)

[Dave Anderson NH]

That's one of the things I like about this forum, I hadn't even thought about an integral ferrule to capture the butt end of the lignum vitae cap. This is a classic example of how we can help each other with ideas and mention the obvious and less than obvious things which one mind alone can easily miss. Extra brains are a great antidote to tunnel vision. While this is a great idea, it adds a bit of work to the turning of the brass, specifically an end boring operation with a drill bit or flat bottomed end mill inserted in a drill chuck in the headstock. Maybe I can give it a shot if, or rather when, I make another batch.

[chaddhamilton]

Great looking work, Dave! Very inspirational.