Clay

This page may seem strange at first, but it'll teach you a tremendous amount about hammers and forging. One analogy to keep in mind is that moisture is to clay as heat is to steel--both make the material more pliable.

Obtain 25 pounds of clay. At the clay store ask for white, low fire clay--Cone 06, if they get technical. The stuff you want is also called earthenware. And that's Cone 'oh-six' rather than Cone six, which is a high fire clay. The cone designations refer to specially compounded materials which melt at specific temperatures. Cones are how ceramicists keep track of the temperature in their kilns.

Clay is usually sold 50 pounds to a box, but many, if not most, clay stores will break boxes and sell you a single sack. The stuff will be a gray, longish square lump in a plastic sack. Keep the sack closed so the clay won't dry out. Rehydrating clay isn't an easy or fun process. Can you use the clay from your backyard or down by the creek? No. For this exercise you need the commercial stuff to insure we're all on the same page.

While at the clay store also ask for soft kiln bricks and handle one to get a sense of the density. They can used for the muffle.

Obtain a baking pan and Plaster of Paris. The pan should be around a foot long. Spray it with Pam or some other vegetable-based non-stick stuff, mix up the plaster and fill the pan. If you want to do a good job of this, put in some 'rebar'. I use the webbing sheet-rockers use to mask joints. Plaster is exothermic, meaning it gives off heat as it sets. So, your pan will warm up nicely as the plaster sets. In a couple hours, tap out the plaster batt and smooth up the edges. In a day or two, the batt will have dried enough that clay won't stick to it. That's the reason for the batt, to provide a working surface that clay won't stick to. Continuing with our clay/steel metaphor, the plaster batt is the anvil.

Obtain a 1" dowel, 2-3 feet long. You'll use part of it as a clay roller and the rest as hammer prototypes.

Cut two strips of 1/8" Masonite, an inch wide and about a foot long. Get a wad of clay from the sack, place it between the strips and roll to thickness. This is not unlike what happens at a steel mill. From this point on it's vitally important that you notice what works and what doesn't. Notice what you do and what tools you fashion to get a particular result. Using the Knife Blank as a pattern, cut out a 'clay blank'. Take a section of dowel and using the end, press downward as if you were striking hot iron with a hammer. In this case just press, you don't need to hit. Be aware of the tendency to roll the 'hammer' face as you use it--avoid doing so. Also notice the tendency to push the clay where you want it to go rather than squeezing it in the direction you want. At it's core, forging is just clever and creative squeezing. There's something slightly counter-intuitive about squeezing the clay to make it do what you want. By-and-large, every problem and situation faced by the forger is also present with clay. After messing around with the Clay Blank you will have realized some of the challenges facing you.

Forging is a very spatial activity. Analyzed in three dimensions, we have three axes, X, Y and Z. The Z axis is the hammer/anvil axis, the axis where the squeeze takes place. Thickness in the Z axis ALWAYS diminishes. And that material has to go somewhere. It goes into the X and/or Y axis. In forging, the Z axis ALWAYS diminishes and the X and/or Y axis ALWAYS grows. In a nutshell, this is the whole process of forging—squeezing material from the Z axis to one or both of the other two. In forging there is a method called 'upsetting', it's used to make a piece thicker. But carefully notice, you squeeze in one dimension to thicken in another. Upsetting is just the process of turning the piece so the axes change. Whatever you do, it's always moving material from the Z axis to the X and/or Y.

The whole trick of forging is about determining WHICH axis grows, X or Y. This is done in two ways: by the shape of the face of the hammer and/or by use of differential heating.

Since we're using the analogy between water and heat as a softening agent, clay is a wonderful medium to understand differential (non-uniform) heating. While clay forging, it readily becomes apparent that wetter clay deforms more than dry. Thus, when the spine of the clay knife is close to the desired shape let the clay blank dry some and then wet the edge portion and forge there.

By now you've noticed that cutting a clay blank the same size as the knife blank leads to a clay knife that is larger than the original. So we have to think backwards and come up with a forging blank, which, when pounded out will end up the approximate size and shape of the knife blank. Once we've worked out the shape of a forging blank which looks like our knife blank (after clay forging) we're ready to proceed.

Be aware that the forging blank you end up with depends to a substantial degree on the shape of the 'hammer' faces employed and order/placement of the 'strikes'.

When you can 'pound' clay into the shape you want, you're ready for hot metal. There's a certain kind of logic needed for forging and clay practice is a quick, easy and inexpensive way to develop it. As your forging ability progresses always return to clay to work out problems, develop new methods/tools, etc. Clay is a way to THINK about forging--forging in general and in a specific situations.