So I'm looking to build a charcoal forge. Specifically charcoal and not coal.

I have heard there are differences in design between them.

Like side blast instead of bottom blast.

What are some tips and guidelines for a forge I can build for general blacksmithing and knife smithing.

Charcoal will work in a bottom blast forge, I forged that way for years. But it should be a deep forge. 8 inches deep if you can manage it.

Firebrick to take up space at the bottom so the fire doesn't spread, as charcoal is known to do helps as well.

Here's a rig I made for use as a charcoal sideblast:

 

 

It's just a modified drop from an I-beam with a hole cut and a pipe welded in. The verticle piece in the back isn't necessary, but it is handy. You could just as easily weld up a 2 piece pan... a back and a bottom.

 

It gives me just a form for a fire pot, so I can arrange fire brick to form the size of the pot I need.

 

It looks like this in use:

 

 

I'm using a bellows, but any sufficient blower would work. The main thing is to get a good, deep fire. Then keep as much fuel over your piece as you have under it. It doesn't take much air to get good heat. I have welded in this fire many times.

 

Don't let the big masonry forge fool you. There is an old burned our coal pot beneath my charcoal rig. You could use any type of heat resistant stand or table to accomplish the same thing.

 

Good luck,

 

Don

I would go with a sideblast , that away you do not have to worry about a bottom piece with hole or slot to get filled up with slag.

I have two side-blast forges that I have built that have bellows that I also built, as well as an old bottom-blast Buffalo forge that has a Champion 400 hand-crank blower.   I have used other bottom-blast forges two of which had bellows, and the rest had blowers.  The main thing I can say is that each forge had something different about it, both good points and not so good points. 

 

Looking for the ideal forge is sort of like looking for the ideal truck. 

 

My humble advise is to visit as many smiths as possible and spend time working at as many forges as possible.  That way you can get a better idea of what features fit your personal needs best, and have a chance to talk to the smiths about why they built their forge(s) with those features.  Fortunately, you live in Maryland, the land of many forges. If you come to a meeting of the Blacksmith Guild of Central Maryland, located at the Carroll County Farm Museum in Westminster Maryland, join the guild, sign the release forms you will then be able to try the bottom blast forge(s) in the blacksmithing school.  Also, when the the historic shop is open, one of us could take you down to the historic forge and you could try the bellows forge there.  We can also talk to a smith or two at other museum forges about your trying their forges.  I will also be taking one or the other or both of my side blast forges to the museum and other area locations this year, if you wish to examine their features and differences in how they work. 

 

If you live near or in western Maryland, Wally Yater has the Western Maryland guild and he is very into making and using charcoal.