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I Forge Iron

My Folding Coal Forge Design


Patrick Kerns

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Hello! I'm gearing up for blacksmithing and will be taking some local courses in Blacksmithing and welding here in the Baltimore Area. I have a backyard where I can smith but I need to be able to move the forge up some stairs into my basement at the end of the weekend. So I've set out to design a folding coal forge. Any comments/suggestions are appreciated!

 

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The top will be some light plate steel, probably 1/8 or 3/16 inch with some angle-iron welded around the edge to keep the coal on the table. Square or round stock pegs will be welded to the base of the plate to allow it to sit on top of the square tube of the table frame. It will have a circular cut out for the brake drum/rotor will will be attached to the standard 2" black pipe setup for a brake drum forge. Air will be courtesy of an old vacuum blower that I tore out of an old vaccum and have converted to act as a blower, handily it comes with it's own electrical already wired it (but only one speed at this point). I'm considering adding an air gate. I'll be using a McMaster-Carr cast iron shower drain in the firepot, surrounded with either clay or refractory cement to create a nice bowl in the drum/rotor.

The folding table frame will be fabricated from square tube steel with butt welds. The top cross bars will be welded to hinges, which will in turn be welded to the corner posts to allow the table to fold once I remove the plate top (side view of folded table picture). The bottom cross bars for the table will have small pieces of flat stock welded onto the ends so that they can be dropped into place, fitting into small slot-boxes welded onto the upright corner posts.

The rotor/drum firepot will probably be welded to the plate top and will have a 2" pipe flange welded onto the bottom so I can screw in the 2" pipe tuyere and suspend it from the top plate in a way that still allows it to be broken down. The salvaged vacuum cleaner blower will be mounted (probably) on a wooden board that will be clamped to a cross bar between the corner posts (or something like that).

Anyhow, that's the plan. Any advice, recommendations, etc. is very welcome. Also, any locals in the Baltimore area who can recommend steel supplies, salvage yards, or a good junk yard (still need to find a rotor or drum) or if you have an anvil that you're looking to sell.

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That is going to be a heavy thing to be moving around up and down stairs.  First thing I would buy is a two-wheeled hand cart...you're gonna need it.  I would not weld the drum to the plate.  Besides, welding steel and cast iron (brake drum) seldom is a good weld...cast iron is difficult and the weld usually finally cracks.  A drum and plate welded together will be a PIA to move anyway.  Just have your hole cut in the table where you can drop the drum into, screw your 2" fittings together hand tight and it won't move at all.  You will lose very little, if any, air from the hand tightened fittings.  My forge has a drum dropped into a hole cut in 1/4" steel plate and not welded.  It has never moved or shifted.  The pipe plumbing keeps it all connected together.  As for the cast iron shower drains, they will work.  I used about three of them, also from McM-C, and they eventually burned up and broke.  I finally put in a grating made from 1/2" steel bar stock.  It's lasted the longest.  I can see you will be making several trips moving the forge.  Good luck with the project.

Edited by arkie
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Greetings Pat,

It's great to see young smiths minds in motion.. Ya got the right idea but I will add what I have done in the past. Instead of hinges just use 3/4 pipe and unions At the long bar ends. It will make the bottom assembly 3 parts and will easily transport up the stairs with a few trips. Others have chimed in with some good ideas.  Good luck on your build.

Forge on and make beautiful things

Jim

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Arkie, thanks for the tips! The whole thing will probably be a little smaller than it looks in the picture - probably only about 2 feet x 3 feet because of weight concerns. I'll probably use only 3/16 rather than 1/4 plate for the top as well. It will break down into  the top, folding table, two bottom crosspieces, firepot, 2" pipe tuyere/ashdump assembly, and the blower, so it will probably be managable. By my calculations the top piece should weight about 54 pounds (2 x 3 foot of 3/16 should weight about 46 lbs plus 8 pounds for the 1 x 1 x 1/8 angle iron around the edges).

Jim - much appreciated! If you mean what I think you mean, you're suggesting that I make the frame out of tube steel and weld unions on where the hinges would go, then screw pipe into the unions during setup. Not sure I fully understand how that would all go together since the unions would be fixed on either end and you could only turn the pipe one way (I'm probably missing something). That seems like it would be a very stable way to put the table together, but it also seems like it would be more time intensive on the setup. Also, the pipe seems a little heavier than the tube steel. Thanks for the encouragement!

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Patrick, you'll like the 2' x 3' size...big enough to pile your coal onto the table.  My forge is a bit smaller, so I had to make some 3" high sideboards that clip onto the angle iron frame.

Arkie - Yes that's the hope, bigger size tables seem to be a nice luxury but it seems like the chief drawback to the classic brake drum forge is no extra room for coal. And at 2 x 3 feet I can probably get a decent propane grill cover and I may just be able to leave the forge outside. But I'll still need the folding feature to get it home in my trunk :).

Edited by Patrick Kerns
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As stated, do not weld the brake drum in place. No need.

Consider putting wheels on one end, and a couple of short pieces of square tubing on the other end. Insert a tube withing the tubing for handles and off you go.

 

 

Edited by Glenn
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Glenn - thanks for the advice. I certainty considered adding wheels, and I may still do it. Unfortunately the back porch stairs I would need to get the forge up features at least one >1 foot steps (yeah, my house is a collection of weirdness) so I would probably need to use a piece of ply to make a ramp. But at least that way the forge could chill on my back porch when not in use. Definitely worth thinking about.

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Arkie - Yes that's the hope, bigger size tables seem to be a nice luxury but it seems like the chief drawback to the classic brake drum forge is no extra room for coal. And at 2 x 3 feet I can probably get a decent propane grill cover and I may just be able to leave the forge outside. But I'll still need the folding feature to get it home in my trunk :).

You can always add sideboards.  The frame would need to be angle iron so the sides could be attached somehow (clips, bolts, etc.)  Here is mine with 1/8" x 3" sideboards (the one on the right was removed temporarily).   You can really pile the coal on there for a small forge.  Like Glenn suggested, put on some wheels, preferably large...10"-12" if you can.  After you set up, it makes moving the forge around SO much easier.

Forge setup Mar 2015 28.jpg

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The sideboards are 1/8" x 3" steel.  The frame is 1/8" angle iron.  I cut pieces of 1/8" steel strips about 3" long and welded them to both sides of the 3" sideboards only.  The sideboards will just slip down onto the angle iron, with the gap on the strips/tabs being 1/8", same as the angle iron thickness.  The strips/tabs on the inside and outside hold them on.  The sideboards are not welded to the angle iron so they can be removed if necessary.  The pictures here are from a while back before I added a hood and put another sideboard on the gap.

 

New forge sideboards 01.JPG

New forge sideboards 02.JPG

New forge sideboards 03.JPG

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Many years ago when I lived in Baltimore, I disguised by coal forge so I could leave it outside.  I made a removable table top out of 2 by 4s, and painted it with a redwood colored stain. The top hung over the edges of the forge.   No one bothered with what looked like a really cheap and ugly fake redwood table. 

If it were me, I would make an inexpensive forge table with removable firepot and blower, and a removable fake redwood table top.  I would use 2 x 4s for legs (stained like the top), and an piece of an old washing machine or dryer shell as the top, with a hole for the removable firepot.  That way it is not very desirable to steal, and even if they did steal it, would be cheap to replace it. 

Personally, I would try that before trying to deal with something that I had to move up and down stairs.  But that is my preference, and may not appeal to other folks.

 

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The idea of the solid stock pins just sounds like a leg stabber to me. I'd work out some other form of connection.

 

My forge is designed to do much of what you want. The biggest difference is my plate fire pot is welded to the table. If I was doing it again, I'd probably leave it loose to eliminate that weight from the table top. The original incarnation simply used steel folding saw horses for legs. That worked very well, but didn't look all that nice for demos. incarnation #2 used 1" solid steel forgings for the legs. The end pieces were solid, and connected by the cross bar  with tenons and wedges to allow easy dis assembly. The solid square stock fits in 1" OF square tube and are forged down to fit the ID. Eventually I'll either cut the plates that hold the square tube back on an angle to eliminate the sharp corner ( why I suggest not using pins as I've been stabbed a few times by mine) or add another piece that slopes back and better hides that connection.

 

Other than the table with attached fire pot/blower that is a bit on the heavy and awkward side for one person to move by themselves, they other pieces are very easy to move and assemble. If I had made the fire pot/ blower assembly removable that would have eliminated at least 1/2 the weight of the current table assembly. I have added some detachable wheels so I can move the fore assembled when I'm doing multiple day demos. That lets me move the forge out and out it where I want it, and roll it back near the anvil so I can chain it all up for security over night.

 

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Edited by DSW
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Wow, excellent forge. Love the legs. Will probably go back to the drawing board this weekend and post up a new design. I appreciate everyone's input!

Also, David - did you use to live in Hampden and make those decorative railings around the neighborhood? I was up in Westminster yesterday buying a blower off a guy and he mentioned there used to be a blacksmith in Hampden.

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A knock down forge that comes apart will be much easier to move and setup tear down. You can make simple socket connections and let gravity hold it together. That way the heaviest piece will be the table and that's not so bad with the pot popped out.

A good way to keep thieves from messing with it is make a simple plywood dog house shell for it and buy a dog. Dogs are good to have around, they'll protect the property and are always happy to see you come home.  ;)

Frosty The Lucky.

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The idea of the solid stock pins just sounds like a leg stabber to me. I'd work out some other form of connection.

 

My forge is designed to do much of what you want. The biggest difference is my plate fire pot is welded to the table. If I was doing it again, I'd probably leave it loose to eliminate that weight from the table top. The original incarnation simply used steel folding saw horses for legs. That worked very well, but didn't look all that nice for demos. incarnation #2 used 1" solid steel forgings for the legs. The end pieces were solid, and connected by the cross bar  with tenons and wedges to allow easy dis assembly. The solid square stock fits in 1" OF square tube and are forged down to fit the ID. Eventually I'll either cut the plates that hold the square tube back on an angle to eliminate the sharp corner ( why I suggest not using pins as I've been stabbed a few times by mine) or add another piece that slopes back and better hides that connection.

 

Other than the table with attached fire pot/blower that is a bit on the heavy and awkward side for one person to move by themselves, they other pieces are very easy to move and assemble. If I had made the fire pot/ blower assembly removable that would have eliminated at least 1/2 the weight of the current table assembly. I have added some detachable wheels so I can move the fore assembled when I'm doing multiple day demos. That lets me move the forge out and out it where I want it, and roll it back near the anvil so I can chain it all up for security over night.

IMG_4171.thumb.JPG.2cc45fbf646176c9548ab

 

IMG_4356.thumb.JPG.2ebe57c0c561e46056169

That is one FINE looking forge, DSW. :) You put a lot of work into the legs and supports.

Makes my simple angle iron frame look kinda primitive (pout...).:(

Edited by arkie
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Thanks guys. It took me 2 years of thinking to come up with a design I liked that  performed the function I wanted and had a good look. I thought about pipe legs but I didn't want that look. I still have plans for more upgrades at some point in the future. Right now the lever for the air gate is just a bent hanger hanging from an edge. I'm thinking about adding a 2nd cross bar on the side with the ash dump and air gate that will also hold the lever, but it will have to be arched to accommodate the length of the ash gate lever. Upgrading the clinker breaker is also on the list of upgrades. What I have works, but is inconsistent and jams often if not cleared regularly. Then there's some sort of removable handle for moving the forge, and wheel upgrades to something nicer than the mower wheels I'm using now. Then there's always a hood, tool racks etc and I saw a forge with great dragon legs on it somewhere, ball and claw feet would be neat... As my skills over the years improve, I'm sure I'll want to use my forge to help show case what I can do.

 

I got offered a nice big piece of copper last week. The more I think about it, a polished copper hood would really be sweet. I may have to talk to that guy again and see if he still has access to that sheet and what he wants for it...

 

There's no reason why yours can't evolve over time as well.

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Went out to my local Pick and Pull type junkyard and found a nice brake drum for the forge, it's about 3" deep with a nice "brim" to it, which is what I was looking for. Also pulled apart a F150 pickup rear differential, popped the c-clips, and got myself two 4340 steel rear axel shafts which are basically 1.5 inch diameter by 32 inch pieces of round stock. Should be enough to make a lot of the tools I'll need for the first year of blacksmithing. All in all was about 50 bucks. They threw in the rear diff pin which I think will make a nice punch for free because they didn't have it on the price list. Not bad for a Saturday morning.

From what I understand the 4340 will be a little red hard compared to 4140 because of the slightly higher molybdenum content but I suppose I'll have to make sure to work it really hot, and that same problem should make it pretty good for hot work tools like a hot hardie.

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Edited by Patrick Kerns
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