When Builiding a coal forge.

[Bwilloughby]

I'm currently working on plans for a coal forge now. I have to wait on the gas forge anyway so I decided to start my autocad plans for the coal forge.

A couple of questions, what kind of material is used as the bottom pan? Should it be lined with fire brick? if not what keeps the constant heat from warping the bottom pan or burning thru it?

Bruce

[HWooldridge]

Bruce,

The heat stays relatively contained to the area of the pot. I built a forge for a local historic society entirely out of wood but I set a piece of 1/8 plate over the portion of the wood closest to the pot, which cannot be seen with coal scattered over the hearth. The pot was a round 12 inch Centaur so I made the plate about 18" square and left a hole in the wood that was covered by the plate but still several inches away from the pot so the wood wouldn't char. We have used this forge many times all day long with no ill effects - the bulk of the heat stays localized. You don't need brick or any other type of liner. However, many of the patent factory forges came with the lips of the pot an inch or so above the hearth so some folks lined this with sand or mortar but anything that traps moisture will greatly speed up the rust-through problem often seen on these forges.

Hollis

[Barney]

I use a brake rotor for the bottom. do some fancy welding for the air and clean outs. In the bottom of a propane clynder. Works very well. I also used the same to repair my big bufflo one in the shop, Brake parts are cheap.and made out of cast. To control the fire I have a 3" x 6" cast ring around the opening to hold the heat better.
Cheers from the North Country

[JimG]

Bruce,
Check out http://www.blacksmithforum.com/viewtopic.php?t=138
for forge plans made from a 45 gallon barrel

[Bwilloughby]

Wow, Thanks alot for all the input

I will keep these thoughts in mind when doing final touches on the drawing.

Thanks so much!

[Glenn]

There are several photos of forges on http://www.iforgeiron.com > Tools > Forges

Autocad is a wonderful idea, but heating and beating is what it is about. In the time it takes to make the ACAD drawing, you can have the parts together and a fire built. THEN make the drawing



This is a break drum forge and 13" or so in diameter. Works well. Clay was added later to change the shape of the firepot and concentrate the fire. Table is 30" square and is a real help.




Same set up but with a much smaller fire pot, maybe 4" across. This is great for ends of stock, twists, and concentrated heat in a small area. Great for forge welds also. The glove (same glove) will give you a size reference that the second forge is just a little thing. Takes only two double handfulls of coal to load it up for use.




If a fellow was worried, he could put a brake drum in the 55 Forge to act as a firepot.




Or you could build a permanent forge.

[Strine]

Speaking of heat at the bottom of the fire. Many's the time I have found bits of unburnt newspaper at the bottom of the duck's nest after a days forging. I'm at a loss as to why but then I don't worry about it much. It;s just a curious thing.

[anon_smith]

Bruce:

A coal forge with a firepot is a vast improvement over one with out, and one heck of a lot easier to weld in.

My first choice would be to buy a cast iron firepot. My second choice would be to fabricate one out of steel. I think if you do a search on fabricated firpot, you'll see some that others have built.

[Bwilloughby]

Autocad is a wonderful idea, but heating and beating is what it is about. In the time it takes to make the ACAD drawing, you can have the parts together and a fire built. THEN make the drawing Smile

My problem is not time, time is what I have too mch of, we are moving to North Carolina in July and I didn't want to have to much to drag around with me. which is why the gas forge is on theback burner now.

When We get moved I'll be super busy, looking for a shop, setting up and practicing

though I like that permanent forge.

[yesteryearforge]

if you would like I can send you drawings for some forges like I make
you can view them in the gallery section of this site.
there are only two potential concerns / the drawings will be in the form of a DXF file and you need a pressbrake to form the forge and firepot as they are made of 3/8 plate but I guess you could cut the pieces and weld them together as an alternative

[elkdoc]

What Hollis has said above concerning the localization of heat around the firepot really amazes me. It's true - I can lay my bare hand on the top of the forge extremely close to the fire and it's not hot. Cool even. Must be the nature of coal, the thermal properties of air flow through a firepot, and forge topography. It is kinda neat, though.

That said, I built my forge out of a wooden frame with sheet of diamond plate for the top. I lined the top with firebricks, because I had access to some cheap ones (less than 70cents ea., if I remember correctly) and was sold a broken bag of refractory clay for nothing. I knew it wasn't really neccessary, but I liked the aesthetics of the brick top for some reason.

A friend from our local guild built his forge much in the same way except he welded a brake drum in place rather than a commercial firepot. He used a piece of stainless steel grating for a tuyere and it works great for him.

[Glenn]

Throw a 55 Forge together. It is quick, easy, cheap, and you can leave it when you move. Take the twyere with you, so it is just a matter of cutting the end off a new 55 gallon drum and your in business again.

That way you have a forge to use while you fabricate your next forge. Besides, two forges are better than one. :roll:

[Bwilloughby]

That, sir sounds like a great idea!

**thinks - hmmm now where to get coal** :)

[Glenn]

Coal is available in NC, but you can go directly to the mines in WVa, Va or KY. Don't know about coal in Fla but it should be available somewhere.

Knock the head (without the bung holes) out of a 55 gallon drum, remove the small bung (for drainage) and fill it with coal. Put the head you knocked out back on the drum as a cover.

One 55 gallon drum holds about 400 pounds of nut size coal.

[Strine]

BW. This is my forge. (cut down 44 Gal drum, cast iron pot with clinker breaker, original end replaced with 1/8th plate, removable handles). You would not have to leave this one behind you could just wheel it to North Carolina. As for drums, 44 Aust gal =55 Us gal and the old petrol drums are much more heavy duty. The one shown has been going for years and years.

[Bwilloughby]

hehe got my Drum, though its a bit beat up.

I'll post as I cut her up.





EDIT - Showing cut up & Dedented



So I can get a brake drum and use as the fire pot?I still need a blower port right?

[Glenn]

Cut the drum to about 5-6" tall. If you need to heat the middle of a piece of stock, you can just cut a slot in the side of the drum. It makes things a lot easier if you get the bottom of the slot the same height as the sweet spot of the fire.


The twyere is just 2 pieces of 1/4" rod inserted into a section of automobile exhaust pipe. The "T" is important in this twyere as you need a clean out separate from the air hole. A longer down tube will hold more material than a short one and require less cleaning.

The "grate" is large and lets a bit more material pass than would fall through a smaller opening. This was chosen to be quick and easy, not because it was efficient. The twyere stands maybe an inch tall the ashes insulate the bottom of the pan from the heat. If needed raise the twyere a bit so there is more room for a thicker ash layer. The brake drum is not necessary, but if it makes you feel more comfortable, then use it.

Don't throw the other half of the drum away, flip it over and use it as a work table.

2 stacks of cinder blocks to support the pan is all that is needed, but make sure it is stable. This may mean putting the stack of blocks just far enough apart so the twyere fits between them. You do NOT want to tip over the 55 Forge when it is full of fire.

This is NOT an exact science, you need to play with it a little. Try it the way it is suggested first so you have a base line of information. Then make changes and see what happens. Add a brake drum to the pan, and see if it makes a difference in the fire and the way it heats. Keep the ideas that work.

When you leave Fla, your 55 Forge would be a wonderful gift to a newbie trying to get started. Just a thought.

[Bwilloughby]

Thanks Glenn, I cut the 55 just below the bottom swell, I will cut down from there to make the pan 6" and bend the cut tabs over so as to not have any sharpe edges. Just one thing I thought of to fix my cut too much goof.

When putting the fire pan in do you just set it in the forge pan or is it fixed to the bottom(Beneath) the forge and a hole cut big enough for coal and fires?

I guessing the purpose of the pan is to have an isolated more concentrated heat source.

I will post more pics tomorrow.

Thanks so much for the help :)

[Glenn]

I just put the twyere directly into the 55 drum, and put the fire directly on the twyere. Ran it that way for a year.

The brake drum never entered the picture till I started playing with the design to see if it would make a different shape to the heat.

Go with the basic 55 Forge and be happy.

[Bwilloughby]

Ok Time for more pictures

The Blower - Though a little big and it takes just a second to spin to a nice gentle draft, it does the job for now. I will get a true forge blower when i get settled, and this one is super quiet.


The fire pot and air ducting/ash can assembly - simple yet effective, notice the plastic tye wraps, my personal touch to the aluminum foil ash can lid.


The dynamic duo - Here to wreeck havok on the neighbors while I burn green coal into coke


Fire! Wooo wooo!!


Now I need to get my chainsaw and go skalking around someones yard for a stump for my anvil :)

[HWooldridge]

Here is another paradox about burning coal. You burn less fuel but more efficiently by putting more coal in and around the fire. The excess actually insulates the coke ring and can be watered for coke production and to concentrate the fire. Beginners often put a little bit of fuel in the pot and are amazed how fast it burns away to nothing. Pile the coal deeply, water the edges and you will have a good neutral fire - suitable for welding and forging.

[Bwilloughby]

I filled the fire pot full to the rim once I got it going .

How do you put out the fire when you are done with it?
I tried to cover the fire pot with a large steel lid, but went out 3 hours later and it was still hot/glowing.

[HWooldridge]

Pull the fire apart with a poker and use a SMALL amount of water to put out the coke. Too much water can blow up in your face (as steam) and break things - especially cast firepots. I saw this happen once at a workshop with some novice smiths and it was catastrophic. Fortunately, no one was hurt but it was scary and shattered a brand new firepot.

I plan ahead and take a few minutes to shut down. I do the initial breakdown, use a little water then start cleaning up the shop. Come back a while later and use a little more water. The second time is usually enough to put the flames out, even if the forge is still warm. Keep the coke for the next fire and let the rest of it cool until you can fish out whatever clinker is there.

[Glenn]

You NEED to put a "T" in the air line. Otherwise hot coals will fall down into the air pipe and burn internally causing the pipe to melt. The "T" should be placed high close to the fire so you do not block the air flow. As the down tube will fills with ash, clinker, and junk, it needs to be cleaned out.

A butterfly valve in the air line to the forge will help control the fire. A second air line can be fabricated to the blower and aimed at the blacksmith to help keep him cool while at work.

You also need to cover about 1/3 of the intake to the fan. It is sucking too much air. Throttled down, it then reduces the load on the motor and the motor doesn't overheat. There is a formula on how much amperage the motor should pull before overheating, but I do not have that information.

Congradulations on completing the forge project. Now, to play in the fire. :D

[anon_smith]

I just spread it out as much as possible and let it go out on it's own, ....but what do I know, I'm just a beginner.

Hey, is that the handle of a well made fire rake I see in one of the pictures?