My Forge

Here is how I built my forge.  Inexpensively.  The boards you see are treated dog eared pine picket fence that has been run through a planer.   The supports are scrap 4×4 from old fences, cut with a 30 degree taper on two sides to support a hexagonal shape.   Like a bee, a lot of what I build has a hexagonal cross section somewhere.

This picture is not much different, but it does show the shape a bit better.  Inside is my old favorite tool, a Royobi 18v drill.

From the top you can see the pipe with it’s holes and the framework that supports the thing.

Here is a better closeup of the pipe.

The pipe sticks out at two ends.  The far side, is connected to a small wet/dry vacuum.  Serious overkill in the blowing department.  I have an adjustable slide on the front hole.  When the forge is running, I can reduce the air flow by opening the slide.  The extra air blows though cooling the pipe and actually cooling me, so I have few complaints.

Here it is all ready to be insulated.

This is an old welders blanket.  Supposed to be fire proof, it isn’t.  It won’t burst into flame so that is good enough.  This is just to keep stuff in, not really do much protection.

This is pearlite.   Basically lava glass, that has been puffed up.  You see this stuff in potting soil a lot.

It is light, insulates,  and does the job well.

This is builders lime.  I pour a few bags of it into a plastic trash can, cover with water, and let sit for years.  The longer it is wet, the better it does.  I use this because it holds shape, insulates, and as the heat cracks it, it can be wet and repaired.

This is furnace cement.  I made a large plug of the high heat stuff below the area where the fire will be, and also coated the pipe with it, to protect the pipe a bit.  The pipe will have to be replaced every now and then, but that is expected.

Three or four holes would be enough, but I can stop them with clay plugs if I am getting too much air.

Here it is after the first fire.  I used regular charcoal, and just let it burn.  I did not want high heat so much as to dry it all out a bit before the high heat.  Forges are normally hot and wet, but the furnace cement will fracture badly if it does not dry out before it is cured to a high temperature.

Here it is after the first high temperature burn.  All ready to go.

Here is the finish the furnace cement put on the pipe.  Nice and solid, this will reduce oxidation of the steel so the pipe will last a good long time.

The walls on the forge are a bit too high.  I am going to have to cut out a bit so that the long work I heat up can remain level.

With this forge, I have tons of room to arrange fire bricks to make small ovens and pretreat coal.  It is big enough to work fairly large steel plates, much more than I usually need to work.

Bob