How to build a coal forge.

   These days the gas forge has become the standard among farriers and blacksmiths.  It's easy to start-up and use.  Compact and convenient to haul-around.  And it doesn't bellow thick smoke or leave one looking like a refugee from a pre-PC minstrel show.

   On the other hand, gas forges are noisy, don't weld as well, produce invisible, odorless, poisonous exhaust fumes, cost more to fuel, require pressurized fuel tanks that are hazardous to transport, and ARE AN ABOMINATION TO THE SMITH GODS!   er... I mean they're less traditional than coal forges.

   A coal forge is a simple concept.  A big tray of burning coke with a means to push air into the base of the fire.  And you can build one for very little money.

   An easy way to start is with a steel container of some sort.  A beer keg, milk can, water heater...  Whatever is about the right size for your needs.  You'll also need something to set it on.  I've used old steel milk crates for small mobile forges, built them into the bed of a truck, and put large forges on a cinder-block base for permanent installation. 

   You're going to need a tool to cut the container.  Circular saw with a metal-cutting blade, acetylene torch, whatever you've got that'll get it done...  Oh, and if you're cutting up a propane tank or some-such, you might want to take off the fittings and flood the thing out with water before you start so that you don't blow yourself to Kingdom Come.

   You can start by cutting a triangular window into the side of the container.  This hole needs to be big enough to get your hands, tools, and work pieces into, and high enough to let you see-in.  The bottom of the hole should be six to eight inches above the bottom of the container...  And keep in-mind that some containers have a rim around the bottom, or concave bottom.  If this is the case, make allowances!

   You're also going to need to make a hole in the top of the container, if there isn't one already.  You can do this by making three or four intersecting straight cuts, like an asterisk, then bending the "petals" up or down...  If you really want to do it right, make this hole to fit a section of stove-pipe so you don't have so much smoke coming out at eye-level.

   Now you're going to need a section of steel pipe a foot or so longer than the diameter of your container.  Something about the size of a regular pickup truck exhaust pipe, but preferably made of thicker steel.  Mark the pipe three inches are so from one end.  From that mark, measure a distance down the pipe equal to half the diameter of your container.  Drill a hole about big enough to accommodate a pencil at that point.  Then drill a couple more holes spaced about an inch apart on both sides of the first, kinda' like a flute.  The holes do not have to be in a perfectly straight line.  In fact, it's usually better if they aren't.

   Cut a hole in the side of the container underneath the big triangular window, an inch or so from the bottom of the container.  (Remember to allow for any rim or concavity the container base may have.)  This hole should be just big enough for your flute-pipe to be pushed through. 

   Cut a similar hole on the opposite side of the container, the same distance from the bottom.

   Now you should be able to slide your flute-pipe all the way through the can, below your triangular window.  Position it so that a few inches of pipe protrudes out under the window, the flute-holes are facing upwards and are spaced near the center of the can.  There should be several inches of pipe protruding from the back of the container.  There should also be around an inch of space between the flute-pipe and the bottom of the container inside.

   Get some aluminum foil and stuff it in around the flute-pipe where it passes through the container if there are gaps.  Stick some wooden dowels, pencils, or drinking straws in the flute-holes.

   Get a bucket and mix up some cement.  You could probably use firebrick mortar, or even firebrick clay...  But I've always done just fine with Quickrete mortar mix.  Mix it a bit thick.  Scoop and slop it into the container, making sure to work it under the flute-pipe.  Fill the container just deep enough to cover the flute-pipe.  Pat the surface reasonably flat.  Once the mortar has set up a bit, twist and pull the dowels out of the flute-holes.  Give the stuff a few days to fully cure.

   While you're waiting, get a really cheap, pistol-style hair dryer.  Take it apart, and gut out everything but the electric motor and centrifugal fan.  (If I have to tell you to make sure the bloody thing is unplugged before you do this, you really don't need to be playing in fire anyway!)

   Most of these things actually have a little DC motor, so splice wires to it, run them out where the power cord used to be (I always recycle to power cord itself for this purpose), and put the dryer casing back together.  Now connecting the wires to a DC power source should cause the dryer to blow cool air.  (If it runs, but doesn't blow right, try reversing the polarity.)  Having a DC blower is handy if you're building the forge into a mobile shop rig, or have a remote shop away from the power grid...  If your shop does have AC power, you can use a cheap trickle-charger for car batteries to power your blower.  Switching between six and twelve volt settings will allow you to adjust the speed.

   Once the mortar has cured, get a bit of aluminum flashing (cut-up soda cans) and a few hose clamps.  Position your blower to blow into the flute-pipe where it sticks out the back of the container, wrap the flashing around both the blower muzzle and the flute-pipe, and tighten a hose clamp around each end of the wrap.

   Now get some heavy aluminum foil that can be folded a few layers thick to be molded into a cap over the flute-pipe where it protrudes out below the triangular window.  Hold it in-place with another hose clamp.

   Turn on the blower and you should feel a flow of cool air coming up through the flute-holes.  Presto!  You now have a coal forge ready for its first fire!  I'll tell you how to build and work that fire in the next lense...

   By taking off the flute-pipe's front cap and turning the blower up to full-power, you can periodically blow the ash and soot out of the flute-pipe.  (Do this every so often BETWEEN uses, when everything is cold.)