Saturday, January 26, 2013

Brake drum blacksmith forge

Ended up working some long hours earlier this week.  That usually means when the weekend comes around I dive into a project to clear my mind.

For the past few weeks I've been collecting the pieces for my blacksmith forge.  As I thought through the design I'd stop by Home Depot or Lowes on my way home from work to buy another piece.  I'd sneak a hair dryer into the garage (don't tell my wife).  I set aside the old brake rotors I took off my truck last summer.  Bought untreated bolts, sheet metal, etc...

 The last pieces came in the mail on Wednesday: two-inch black-pipe flanges.  Amazon prime is great for buying odd  hard to find stuff, shipping is free on anything coming directly from their warehouses. The home improvement stores did had the right size flanges, but they were galvanized.  A note if you ever try something like this, galvanized metal and for that matter any zinc coated metal will create zinc fumes when heated to high temperatures.  Zinc is normally great for the body (it's even in cough drops), but when burned it creates zinc fumes. When these are inhaled they can cause fever, chills, nausea, headache, fatigue, muscle aches, joint pains, shortness of breath, chest pain, cough, a burning sensation in the body, shock, no urine output, collapse, convulsions, shortness of breath, yellow eyes or yellow skin, rash, vomiting, watery or bloody diarrhea, low blood pressure, and ... death if untreated.  All of those sound like things I'd like to avoid.  For that reason I took pains to ensure the entire forge is built from untreated metal.  I'd probably be fine with a few zinc bolts of flanges in there, but I've gained more patience as I get older.  There was no pressing reason to take short cuts.

The design is straight forward.  Two inch pipe is used for the frame and to direct air to the firepot which is a brake rotor bolted to a pipe flange.  In theory the ashes should fall and collect in the bottom of the vertical pipe which has a removable plug on the bottom for cleaning.  The hair dryer provides more than enough air (maybe too much) and is connected to the horizontal pipe with a rubber coupling.  I cut and drilled some sheet metal to form a grate in the bottom of the fire pot.  I intentionally made it very tight fitting so I ended up just pounding it in the last few centimetres to the bottom of the pot and around the bolts. I expect that as I use the forge more this metal will slacken and lay in there even nicer than it does now.  I reinforced the bottom of the grate with some round stock I bent into a zigzag pattern, so the grate is probably overbuilt.The cooling fins in the brake rotor made a perfect place to insert a bar to hold the workpiece or tools as shown here.

It only took two hours to cut, drill, bolt, and screw everything together.  During the first uses, the vertical pipe remained cool 10 or 12 inches below the firepot.  I could keep my fingers on it until 2 or 3 inches below the pot even after running the forge for an hour.  I think this is going to work out great.  Currently I only have a 9lb anvil that I got for free, but if the forge works out this summer I'll keep an eye out for a larger one.

Some future improvements to the forge include a larger area to hold fuel at the ready, probably a small sheet metal tray I'll bolt to the side of the pot.  Maybe I'll come across an old baking pan. I probably won't add a chimney or anything fancy to it since I'll only be using it outside. I should be set for making all sorts of metal projects this coming summer.  Stay tuned.

If you're interested in making your own, there are many different designs of forges on youtube or the web.  I've seen functioning ones made from old sinks, brake drums, stoves, etc.  The fun part is working with the materials that are available to you and making something from junk.

Brake Drum Forges on Youtube