Thursday, November 10, 2011

Choosing a Hammer




I started with what I viewed as a “standard blacksmith’s hammer.” It was the commonly available American (also called British or German) style weighing about 2.5 pounds with an octagonal face and cross peen. It worked well but as time passed I got more picky and acquired and made more hammers.


Every day I work off of two Peter Wright anvils. The larger one is beside the coal forge. A slightly smaller one is at my torch station where I work on small pieces. At the coal forge anvil the primary forging hammer is a Swedish pattern with a mushroomed cross peen. I described it in the April 26, 2011 post. I use a slightly lighter version on the other anvil.


Around each anvil is an assortment of hammers of various styles, weight, handle length and face radius. After 10 years in the studio they have all found their resting places and don’t travel around much.


Selecting the hammer of choice for a task has become something like an intuition and a bit difficult to explicate rationally. Yesterday, I drifted some holes for lag screw mounting of plant hangers. I used an antique hand sledge weighing about eight pounds. I think some people call it a drill hammer. It is great for driving a drift but I couldn’t use it for a forging hammer because I couldn’t swing it fast and accurately enough and it would wear me out in no time.


If I want to upset the end of a 3/8” round rod, I’ll get a one pound ball peen with which I can hit a lot of light blows quickly. For fire welding I use lighter hammers and have several even lighter Repoussé hammers with elongated heads.


I rarely use the striker’s sledge as the power hammers seem adequate for most purposes. My only rounding hammer and an antique three pound ball peen lay by one of the smaller swage blocks. They have the shortest radius faces (most curvature) of all my hammers.


On June 23, 2011 I wrote about how I like to modify the end of the forging hammer handles to fit in the hardy hole. The optimal handle length varies for me I don’t have a good formula for it. The same thing goes for the point of grip. Most of the time, especially with a Hofi style hammer, a short grip can deliver enough power with accuracy to do the work. If I’m wailing away on something my grip slides back to the end of the hammer like a carpenter using a framing hammer to get the velocity for powerful blows but accuracy can be compromised.


With experience and experimenting I have decided on the handle circumference which feels best for my hand. It is a subtle thing to get optimal. A large circumference gives the best mechanical advantage to controlling rotation but most of the hammers I have bought I put on the belt sander and reduced the diameter of the grip area to fit me more comfortably.


Considering how radius is used to move hot steel, I rely more on selecting the backup radius on the anvil than by varying the edge of the hammer face striking position. Trying to use the toe or heel positions, particularly, seems to cause more wrist strain. The worst strain risk, though, probably comes from working too cold. Work hot. Take another heat.


Making a hammer is a good lesson for a student and an image shows one of three hammers made in the studio by a glass artist friend for his sculpture work. But, today, if I needed another, I’d just buy one from a smith who specializes in hammer making. Their prices are very reasonable.


The other image shows me with my first hammer at age two. There is a lot to learn about using a Birmingham screwdriver. Start while you’re young.


http://www.persimmonforge.com/

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