I apologize, when you do this a wile, some things just become so common you don’t think about it. In this case it is the fact that the stock lays on the hearth and the center of the fire is at hearth level.  

19 hours ago, Charles R. Stevens said:

So tell me your prefers fuel, coal or charcoal. Or both? 

Give me an idea of your tool access and skill level. 

Then we will get down to it

I dont have a set fuel, both is easily accessible. My plan is to eventually forge in my garage. Ill have the forge at the back with the.garahe door open for ventilation.

I have access to your common tool box with family.members having more sophisticated tools.

I have a basic skill set but again my father in law is pretty handy.

Ok, so charcoal likes sideblast forges and coal didn’t care, so I would recomend a side blast. 

That said, I would recomend cutting a one inch notch in each side, say 3-4” wide on looser sides (the side you plan to work from and the opposite side. Now measure down from the bottom of the notch and cut or drill a hole 3 1/2” in center from the left side to exept a 3/4” schedual 40 tuyere.

for fill adobe is ideal (30% clay and 30-70% sand is ideal but just about any subsoil will work. I recomend placing a brick in the bottom so it sets 1” below the tuyere. This simply keeps you from digging to deep when your cleaning out the fire. Not nessisary but helpful. So from this point we play wit mud patties. Slide your tuyere in (you may wrap paper around it so the mud dosnt grab it) set the end of the tuyere about 2 or 3 inches from the center and slopes down about 5 deg. From here build up the mud so you are an inch below the rim and at the bottom of the side notches (this let’s you keep coal on the top of the hearth). You want to form a trench, state sided on the side the tuyere comes in from and the opposite side, wile sloping the other two sides about 45 deg. So you have a 4-6” wide slot about 11” long.

at this point you can either use a couple of bricks on top of the hearth to coral the fuel (you want fuel piled up on top of the fire). Opttinaly you can use mud to build up side walls.