Pre-Heating Anvils in the Winter Time

by Albin Drzewianowski

Especially if you have an older forged anvil, a Peter Wright, Mouse Hole, etc, you want to pre-heat the surface of the anvil if your blacksmith shop is unheated. There is a chance for cracking, especially around the hardy hole if you are hammering on an anvil that is below 20 to 30 degrees F.
This is not so much an issue for cast steel anvils. However, it is still worth warming up the surface. Imagine laying a red hot piece of 1/4" steel onto an anvil that is under 30 degrees F. It will suck the heat out of the steel almost instantaneously. Pre-heating will give you more hammer time, before the stock has to go back into the forge.

My shop is an unheated pole barn, so this is something I deal with in the winter time. I have some blocks of steel 3/4" x 3" x 6" that I heat up in gas forge and then lay them on top of the anvil. I slide them around so that they don't sit in one place for too long. Using 2 blocks of steel, I do 2 cycles and that warms up the top of the anvil nicely. I did the same thing, heating them up in my coal forge, before I got the gas forge. But it was more work getting the blocks heated in the coal forge, I had to keep moving them around since the coal forge tends to give more of a spot heat. This is one time when the gas forge really out performs the coal forge.

I will also clamp those heated blocks in my vice to warm up the vice jaws. I usually do this after the blocks have sat on the anvil for a while. I do not clamp orange hot blocks in the vice.

I also have an electric engine block heater. It has a magnetic base and sticks to the anvil. If I know I will be forging later in the day, I plug it in and place the heater in the middle of the anvil face. Then once I start forging, I move it to the side of the anvil. Just have to remember to unplug it when I am done.

Something I have heard about but have not tried is to make an insulated box that fits over the anvil and inside the box you have an incandescent light bulb. Theoretically that keeps the anvil from getting too cold. You want to be careful how you set up the light bulb that you don't set the box on fire. The box I heard described was just a big cardboard box lined with the pink insulation batts.

Albin Drzewianowski

-- RebStaup - 25 Jan 2008