Advice on making a coal forge

[EbinHeadrick]

Ive worked with my schools (only) gas forge for about 3 seconds until the valve stem broke and started spewing fire across the shop. It was older then sin and was pulled up from dust though so we didn't have high hopes....

Anyways I'm trying to build a coal one now, It (hopefully) will be shown at State Fair of Texas come October if I finish it in time. 

I'm just so confused on where to start, Ive read about just a box of dirt forges but I suppose I'm looking for something a little nicer? I know nothing about how the mechanisms work and every rock I've turned either I was too dumb to understand or I just didn't find helpful.

please note I have all tools at disposal and I could weld some sheet metal or something to create one, I just don't understand anything beyond making a box to hold hot coals. Something about airflow and vents? Air-con has never been my specialty.... 

Thank you all in advance 

(sorry if this post is in the wrong category or anything))

 

 

[Irondragon Forge ClayWorks]

Welcome from the Ozark Mountains.

There are quite a lot of threads about building a coal forge here in this section. A search like mentioned in the "Read This First" thread tells how to do the best search. The search function on the forum leaves a lot to be desired.

The sticky threads above will give you a good start.

I can't control the wind, all I can do is adjust my sail’s.~ Semper Paratus

 

[Frosty]

Welcome aboard Ebin, glad to have you. If you put your general location in the header you'll have a much better chance of meeting up with members living within visiting distance. 

What do you want to use your forge for specifically, in a general sort of way. For example if you were wanting to make cabinet hardware a clayed cast iron skillet with an ash dump and tuyere makes a fine forge for small products. Nails, cabinet handles, hinges, corners, etc.

If on the other hand you think fireplace tools is more like it you'll want a table large enough to support long stock, coal and fire tools. 

Most guys like a firepot and a disk rotor and washing machine door works a treat. Or whatever you come up with for the table, sheet steel, 16ga or thicker. Cut a hole in the table large enough the hub of the rotor drops through and small enough the disk rests on the table. Clay the table with a mixture of approx. 3pts sand to 1pt clay, 2-1 works well. The sand allows the clay to vent steam and some movement as it heats and cools so it doesn't crack. Line the "firepot" with the same mix. Do NOT make mud and plaster it or it will shrink check / crack for sure! Only add NUST enough moisture so you can ram it hard. I use a wooden mallet or the end of a baseball bar to ram it.

If you use the brake rotor you can supply air up through the center hole. I weld a pipe nipple to a piece of plate that fits in the rotor, the clay will seal it up nicely. I screw a pipe T fitting to the nipple with the "drop" horizontal for the air supply and the run facing downward. It would look like a T on it's side. Yes? Another short nipple facing down from the T is your ash catcher and you cap the bottom with an exhaust flap cap. The drop gets another nipple to a your blower, exhaust flex pipe works nicely. 

For the air grate simply bend lengths of 3/8" or 1/2" round hot rolled steel into hair pins with maybe 3/8" spaces between the legs and longer than the hole is wide. You lay these over the opening in the bottom of the pot, the clay will hold them in place. The "hair pins" are easy to rake clinker through so you can dump it later and they're cheap and easy to replace. Place a steel bucket under the ash dump so when you reach under the forge with your tongs, fire rake, hammer, whatever and flip the exhaust flap cap open the ash and burning coals fall into a few inches of water. 

I framed the table with 2" angle iron flange up to  make a rim on the table and welded sockets in the corners to accept 2" sq tube legs. I'd just weld the legs on were I to do it again I was thinking portability when I built it but it hasn't moved in 25 years. Covering the table with split hard fire bricks prevents the table from being damaged by fire and makes the surface a bit higher than the top of the rotor disk so it's easy to rake coal into the fire. Fill the gaps with rammed clay and ram it really hard, any bits that scrape off make clinker.

Frosty The Lucky.

[BsnNFrnt]

Here is a very rudimentary example of the brake drum style with the blower vent running right through the middle. I plumbed in 1” steel pipe from the bottom and filled the rest in with dirt. A $30 dollar online blower and a little bit of screen to keep klink out of the tube and I was running. 
I don’t coal forge much, but I can. Hope this helps.