I've got an idea on how to build a forge (charcoal or coal) and figured this would be the right place to post it and see if anybody could tell me if it was good or not before I spent any time constructing it.

I've got an old disc (as in implement) that 32" in diameter, about 7/16" thick in the center, and the depth is about 4 3/4". I was going to weld on a 3 short pieces of pipe into which I would insert the legs. And use some flexible exhaust pipe or whatever I could find laying around in a T formation with a hairdryer to supply the airflow and a can on the bottom to catch the ash. I got the idea from an issue of The Backwoodsman I was browsing through where they described this setup but with a brake drum. I thought I had an old brake drum lying around, but lacking that I remembered this big old disc I had. I've a piece of heavy expanded metal I figured I could lay in the bottom to keep the fuel off the bottom and allow the air to circulate.

My questions are is the depth going to be enough? And should I plug the 6 smaller holes around the large on in the center I was going to use to blow the air in or should I leave them open? I figured if I got really inventive I could fit piping to all the little holes as well as the big one and have a larger hot spot to heat up bigger projects.

Thanks for any help.

Mike miller might be able to help

I've seen brake drum forges so it definitely could be done. I'd google it and see what others have done.

My neighbor built one like that, I'll get pics tomorrow for you

Not to get totally off subject, but where did you find a disc that big?

I've been wanting to get a large disc for building a fryer out of. Didn't know they ever made them that large.

I wondered about the size as well.

A question on the fuel?
The old time blacksmiths used forge coal.
The softer coal does not burn as hot.
Is charcoal a good fuel for knife making?

Thanks guys. Googling it brought up some references to having used one like that, but no real specifics, or else my google fu sucks. That is always a possibility.

Maybe Miller will see the thread and pipe up?

The brake drum setup sure seemed easy, and there's a ton of pics and tutorials. I was thinking if I got to the point I was good enough this setup would allow me to work on a pretty big piece.

Thanks Drummond, I'd really appreciate it.

The disc was on my property when I bought it. I've been trying to decide what to do with it for several years now. Too curved for a target, I thought about putting some short legs on it and making it a firepit, but the blessed wind makes sitting around a fire in the backyard a pretty rare possibility.

Check out sites like Anvilfire.com. You will need to line the bottom with clay and lump charcoal will work fine.

If this is something you really want to do, I would look into building a gas forge.

When I was a kid on the farm, we used a disk plow that had four huge disks to turn the earth over. We had various small pothole sized sloughs on one piece of land that would plug an ordinary plow. My guess is the disk blade may have come from machinery similar to that.

Billy Goat these guys have more experience than I do . But the brake drum forge seems to me the best. Cut a section out of the side to get your metal to the fire. You want depth of the fire so the air blowing through it does not create problems.
A small blower for air and a method of controlling how much air you feed to it are critical.
I used the old blacksmith forges and have a propane one now. The propane means a more controlled temp but coal is do able. You just have to watch them more and have to clean them out to make your fire cleaner.
As far as your disc I've always been fascinated by the guys on Texasbowhunter who use them to cook on.

I hadn't realized I needed to line the bottom, that probably saved me some heartache. I messed with gas forges before, and have been planning on buying one for a long time, but I think it'd be neat to work over a coal/charcoal one.

Thanks Mike. If I make this one into a "disco" as I've heard them termed, I could feed a pretty big crowd! The ones I've seen were pretty small and worked pretty darn good.

I did too until I tried it. It might be fine for quick things needed around the farm, and you can make knives on one but you better like blowing black snot if you do a lot on one. I have also burned up a piece of Damascus real quick because I got in a bit of a hurry. That was 6 hours gone in about 6 seconds.

You can actually build your own burners and use lots of different things to build a gas forge. Check out the Anvil Fire site and one called iforgeiron.com or something close that you can find by googling. You can also ask in the makers section at bladeforums for links.

Hey, you really the simple knife and metal forges people make on youtube. Some are little more than pipes and a trench in the ground! I need to better hone my skills in other areas first, but here is one I am keen to try:

I am going to add that the vid that I posted has some potentially critical info if you thinking of going with a gas torch, as I ultimately intend to

http://knifedogs.com/showthread.php?17192-New-forge-!
One of our Oklahoma Knife Group members made this forge. it is a glass blowers forge that he uses for his damascus. It operates on about 3 pounds of gas pressure and is very efficient.

I got to play with gas, charcoal, and coal forges at the New England School of Metal Work in Auburn Maine. They make their own charcoal out of scrap wood behind the building. I can tell you that you can work over coal for a long time. You have little time with charcoal. You go through charcoal quick! They bag it up and we were using a lot. The gas forges were cool but I got a lot of scale with the gas. You don't get as much with the coal. I think it smothers the air out around the steel, and it stays cleaner. That's interesting.

If using Coal, a lot depends on the grade you can easily get.

I have seen some nifty forges using metal wheel barrows as they are deep enough to keep the heat off the bottom, which I think maybe a problem with the disc.

There is a neighbor that is a blacksmith doing o lot of ornamental iron work and although he uses mostly gas forges, he orders his coal from a farrier supply store.

You might check https://www.oleoacresfarriersupply.com/ to see if they carry it and to get a reality price check.

BGG-
I woud not expect the steel disc to hold up well with the heat of a coal fire. It would need a liner of clay as suggested or fire brick. That will make it tough to clean out ash and clinkers.

A large wheel (cast iron) is a common way to go because they can take the heat.

There are plans online on making a hood from the sheet metal jacket of an old water heater. With your wind, I think that would be sort of handy.

As others mentioned, coal quality is a big variable. Local coal here is so soft, it's only a month older than firewood. Good coal has to be shipped and shipping makes it too expensive. Do you have a local source?

Figuring on scooping up some wet clay somewheres and lining the disc.

Haven't gotten far enough to figure out the sourcing of the coal. Project got put on the back burner, trying to figure out a new place and all the awesome crap that goes along with moving and packing and financing and inspecting and andandand

Will get 'er built hopefully this winter and hammer out some coathooks or some damn thing to get practiced up.

Once I find some coal.

I promised pics and dropped the ball...









My neighbors name is George and he calls this his "George Forgeman"

yer missing a bolt on yer tablesaw leg......

That's really cool HS! Thanks for the pics.