Here are some plans for building a charcoal burning adobe forge. It is specifically designed for the bladesmith, but will work well for a variety of tool making applications. I used this forge for over two years as a professional knifemaker. I highly recommend trying this design to anyone interested in using natural charcoal as a fuel for bladesmithing. It works best with a hair blower as the air source and the only reason I am still not using this forge today is because I no longer use electricity in my work.
I go into great detail on the materials I used, but with a little imagination you can easily substitute what I used for what is readily available to you.

This charcoal burning adobe forge is very Neo-Tribal in the sense that it combines ancient techniques and natural materials that are readily available at an affordable price. The forge can be built and powered with minimal tools at a nominal cost. It can comfortably handle up to a 12 inch blade not counting the tang.

The forge is a little slow for the first few heats but once the crucible gets hot it will easily heat 1/4"x 2"x 12" of steel in under 3 minutes. It burns about 2 pounds of charcoal lump per hour and will get hot enough to forge weld. The size of the forge can be scaled up or down to meet your specific needs. I personally used this one for over two years to forge large bowie and dagger blades.

The first thing you need is adobe. Adobe is typically a mix of clay, sand and water. I saw a documentary on adobe missions (local PBS station) where the adobe was made with a "cactus tea" instead of just water. I decided to make my adobe this way to aid in weather resistance; my forge is outside. In some parts of the country cactus may not be available. If this is the case just use water instead. The cactus tea will aid in weather resistance, but it is not an absolute neccesity.

First gather up 12 large prickly pear cactus pads and burn off all the needles over a camp fire. Cut them into chunks, place them into a 5 gallon pot, fill with water, cover and boil for three hours. Mash them into a pulp while still in the pot and boil for another hour, always keeping the water level as high as possible without boiling over. After this is done, strain the liquid through some cheesecloth into a 5 gallon bucket. Discard the pulp (compost pile!), add water until the bucket is full and mix thoroughly. You now have 5 gallons of cactus tea. Pour half into another 5 gallon bucket and set aside.

I found the clay portion of the mix in the banks of a nearby wash. It is a reddish colored clay chocked full o' rocks. I cleaned the clay by putting it in a 5 gallon bucket and adding water to break it up. I reached in and broke up the clay as best as I could with my hands, picking out bigger rocks as I went. I fashioned some wire mesh into a scoop and filtered the clay through it right in the bucket. I kept this up until I was satisfied all the rocks were out. At this point I had a clay slurry about the consistancy of a thick pancake mix. If it looks a little thin, add clay or set the bucket in the sun and let it evaporate until it looks right.

Now, gather a few gallons of fine sand and a couple gallons of wood ashes along with an arm load of dead grass, dried moss or straw. Take one one of the buckets of cactus tea and add in one gallon of clay slurry, one gallon of sand and one gallon of wood ash. Mix thoroughly with a stick or something. Don't use your bare hands. The ashes in the mix along with the abrasive action of the sand will literally eat the skin off your fingertips. Use gloves when needed. Don't add any dead grass yet.

Build the base of your forge with four 8"x8"x8" cinder blocks, two on the bottom with the other two broken into "U" shapes and stacked on top. (See figure 1) The sides of the cinder block that you broke off to form the "U" shapes can be further broken down and used as filler in the bottom two blocks. Mortar the four blocks together with the adobe you just made. Now it's time to assemble the piping.

I used one inch steel pipe and fittings purchased from the local hardware store for less than twelve bucks, and it can be found cheaper from large suppliers or by scavenging. Here is the material list:
1-1"x8" nipple (threads on both ends)
2-1"x12" nipples (one can be longer)
2-tees
1-cap
1-elbow
2-plugs

You will also need PVC adapters to match the diameter of your hair blower or other blower outlet.

Do not use galvanized pipe, because when it is heated it creates poisonous gases!

If you would like to continue this tutorial click here.
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