Hammer Dressing and Cow Pies

[Glenn]

Many topics have been discussed before. In chasing down references posted on another thread, The cow pie analogy of hammer dressing by Shane Stegmeier February 6, 2008 showed up.

As they say, pack a lunch and a cold drink, and do a little reading.

The things you can learn by reading IForgeIron. (grin)

The cow pie apology is very helpful to get people to understand how the steel moves under the hammer. Hit a cow pie with a stick: it divides along the line it was struck. Hit it with a brick: and the pie flys mainly away from the long sides of the brick, and less along the short sides, and only a little at the corners. Drop a square paverstone on it: and the pie will fly away from the sides, and a little bit at the corners. Drop a bowling ball on it: and the pie flys equally in all directions.

 

Other information on hammer dressing from the same research follows:

On 2/3/2008 at 10:46 PM, HWooldridge said:

Here are some numbers:

Radius across the face (both directions) - 24".
Radii on the corners - 1/2".
Radius across the peen - 12".

Don't laugh at these figures - get a big compass and draw them on your work table, then lay the hammer down for reference.

You will have to change your style enough so that the hammer can be used on its corners. Once you get loose with the hammer and swing from the shoulder, you'll be amazed how fast you can draw a piece of material - especially if you combine it with a similar radius on the edge of the anvil.

The face of the hammer is primarily for smoothing - most of the work is done with the edges and the peen.

 

On 2/4/2008 at 4:11 PM, HWooldridge said:

Tie a piece of string to a pencil and go out 24" from the point, then hold the string and swing the pencil a few inches so you can see what that large a radius looks like as drawn on a table top. Lay the hammer down flat on the table with the face just inside the pencil mark. That's about how much radius you want across the face.

From a practical perspective, it's easier to simply do what Richard suggests and dress the face on a belt sander. However, I threw out my arcane geometric explanation so you'd have a point of reference.

 

On 2/5/2008 at 7:24 PM, mcraigl said:

Dan,
Another way to visualize Hollis' suggestion... I take a straight edge and hold it on the face of the hammer. You should have 1/32 - 1/16 gap on either side from the front to back and slight less from side to side. At least that's how I like my faces dressed based on using many different hammers belonging to other smiths. Also, on the pein end, it needs to be almost flat front to back, with a similar crown side to side as the face. I had my peins too sharp for a long time and after watching Mark Aspery pien out material for a leaf and ending with a very smooth surface I had him dress my pein, and it makes a heck of a difference. Not nearly as aggressive, but very much more controllable. Anyway, that's my $.02
McL

 

On 2/5/2008 at 0:34 PM, bruce wilcock said:

The sheffield cuttlers made a hammer then shafted it with slack wedges, before they heat treated the head, then used it for a while to become there own hammer through use. Then took of the head lightly polished the face hardened and tempered and drove the wedges home. I still do same.

 

 

 

[SJS]

Bruce's comments on the Sheffield cutlers hammers has always been a favorite of mine.  They were working on good sized anvils, Bruce had mentioned that he picked up several 7 hundred weight anvils when he was back in the Sheffield area.  They were also doing blade work, and using a long faced heavy cutlers style hammer.  At the end of your hammer stroke, where the hammer falls on the anvil face, especially doing a lot of blade bevelling is crucial.  Forging the soft face back to where it landed just prefectly, and then dressing it, and hardening it is a brilliant idea...  But the face was essentially dressed for one man, at a particular anvil, at a particular height.  If you are bouncing around on several different anvils, all of which are set at different heights, and doing a wide variety of work the technique isn't quite as effective as if you were dong blade work on one anvil...  You would still need to physically compensate for the differences in the anvils height, and even the type of work.  Anvil height effects the total ergonomics of the blacksmithing system of hammer, anvil, and smith.  Too many people end up with the anvil at the wrong height, and it bothers their back, or their shoulder, or elbow, or their wrists/hands.  If you have to always compensate for the anvil being at the wrong height it is going to hurt eventually, weither it is too low, or too high.  For some people the discomfort is immediate, others it takes years for it to wear them down.  People are endlessly adaptable, but don't push it.  Work very hard to figure out what is the most comfortable height for your anvil, and what is the most comfortable and effective swing for you.  It makes a huge difference...

I have cracked and crushed a number of hammer faces over the years.  I use the edge of the face, hit hard, and am often working harder alloys, or thinner stock, like blades...  It's generally the left edge or the heel of the hammer since I am right handed, or I forge a flat spot on the curve of the pein... I have noticed that farriers often see their tools modify themselves over time, as the hammer wears away and is deformed unevenly from how the farrier uses the tool over their carreer,  Sometimes that wear improves the tool and makes it better for the purpose the farrier is using it for, other times it goes past what is useful and efficient, and to tool needs to be rebuilt or replaced.  I'm sure that there are a number of blacksmiths who have worn hammers and other tools to the point that they work better than when they were new and too sharp... But I have seen it more often with older farriers, who's favorite clipping hammer is positively deformed, but they can draw a lovely clip with that hammer...  Another good reason NOT to use a supper fancy high alloy steels for making hammer heads.  Its bad enough when a water quenched medium carbon steel spalls.  It is often much worse when some air hardenind steel harder than your anvil finally fatigues and blows.  If you do this long enough you will wear your tools out, and they will need to be rebuilt or replaced.  It is best to figure out what works best for YOU, what lets you get the most work done, with the least amount of pain, and the most pleasure...  Good tool that suit you, makes the work more pleasurable.