Which sands or clays repel slag? The silica sand sticks to it.

Yes sir, coal slag and scale stick to clay and sand. Coal ash and wood ash added to the sand/clay mix help prevent this. 
not much of a problem with charcoal. That is if you don’t burn up a lot of steel. 

I hope I am not a repeat of every other question about side blast forges, but I spent about an hour trying to heat and taper a 1/2 inch piece of steel, and trying to find the sweet spot in my forge was incredibly difficult! I have forged with a mentor in his bottom blast coal forge, but I used a half a bucket (5 gal.) of charcoal and only got some pretty rough tapers to show for it. Is this normal or is there something wrong with what I am doing? 
 

I did what was suggested and tried to raise my tuyere an inch above the forge floor, but I think it ended up being a half inch. The best heats I got were when the steel was about an inch above the tuyere. I tried a little experimentation, but nothing else seemed to work.

 

Also something I noted was that the charcoal around the steel was up to temperature, but the steel wasn’t.

Thanks for reading through my long winded thoughts!

Why such a wide fire trench for such small stock? You're heating 1/2" bar and your fire hole looks to be about 6" wide and 10"+ long. Any and all charcoal in contact with the fire WILL catch and burn. 

What size are the charcoal pieces? The smaller they are within reason the more surface area they have to burn and consume oxygen. When I burn charcoal, usually in a campfire I break the coals into pieces peanut to walnut size. Smaller means more surface to burn and more concentrated heat and a slower spread. The oxy will be consumed closer to the tuyere so you can put your steel closer to the fire's heart without it scaling up. 

Yes, it's common and normal for a beginner to burn excessive amounts of fuel learning fire management. It's just part of the learning curve, we've all been there. Welcome to the club. 

Frosty The Lucky.

What's your air source?  Charcoal doesn't take much so bellows or hand crank blower helps save charcoal.  Also how big is your tuyere?

Sometimes too much air moving too quickly through the fire can actually cool the metal as it blows across it. 

Same thing I was posting, the trick is to find the right amount of air blast and size of fire pot.

Thank you for the quick responses! I will definitely take what you said into account. My charcoal was mostly small enough, but there were definitely some pieces that were too big.

I am using a hand crank blower, and would once in a while give it a good blast to clear the ash out. I varied in how fast I went.

I find 6” wide to be to wide for the trench, 4” is more effecent for me. 

I have more questions: I remade my fire pot to be not as wide, but I still had a very hard time lighting the forge, as well as getting my charcoal to get hot enough. It seemed like the fire didn’t want to spread to the rest of the charcoal.

 I wonder if I was just too impatient to let the charcoal catch? I had this same problem the last time I tried to use a side blast charcoal forge. I am attaching pictures to see if what I made should get me the results needed, because then I have narrowed it down to operator error.

P.S. The 3/4 pipe is 1 inch above the forge floor

Forge design and fuel management are related but different issues. 
I find a trench 4” wide, 6” to the bottom of the tuyere and about 8-12” long. I slope the ends to the bottom. 
As to fire management, I start the fire with wood kinling and paper, then add charcoal and air. 
 

Thanks Charles. And which side should the tuyere come out of? The 4in or 8-12 in?

Hi Will, here's what my charcoal grill forge looked like (mine was formed from ground clay rather than brick, but same concept). Mine was a bit on the wider side at 7" rather than Charles' suggested 4" (and it did burn up more charcoal than I needed) - and sloping from 7-10" long - and tuyere about an inch from the bottom (on the long side) and protruding about 1/2 inch. The pipe was smaller than the hole cutout so I had to add clay to keep it in place - and inevitably would chunk a piece off during forging when removing clinker - so ignore the visible protrusion in the pic. I would have covered that back up with clay before my next forging. 

I kept the excess charcoal on the front & side ledges so I could just push them in when needed.

The best position I found for the metal was horizontal just above the tuyere - which is why I added the cutouts on the sides. 

As for air, I used a hand pump and I saw above that you have a hand crank blower so that's good. When I used charcoal, I would give a few hard pumps to blast the air and then just slow steady pumps after that for as long as the metal was in the pot. Too much air would just push the heat right on past the metal. Not enough air wouldn't keep it hot enough. 

When I tweak my bottom blown coal forge for charcoal: I build 2 walls of fire brick about 4" apart and parallel and back fill with adobe from a stack of decaying adobe bricks that a previous owner of my house left me...

For because I turned my bottom blast rivet forge into a side blast with an elbow over the existing air grate sealed in with packed soil and a nipple to a fire brick "trench." It worked well for charcoal or wood. 

Frosty The Lucky.

Charcoal has a sweet spot, lol. The historic record seams to indicate tuyere of 3/4-1” ID. As 3/4 schedule 40 pipe comes in close to 7/8” (schedule 80 is almost spot on 3/4”) from there we experiment with what it takes heat 6” of 1” stock to welding heat. For me that’s about 5-1/2” 

know as a demo forge I use a double action manual bed pump with a 1/2” schedule 40 tuyere. 2” is the sweet spot for welding heat on 1/2”

if you make a template that is 6x6” square and then cut on the diagonal you have a good shape. If you then measure up an inch and a half from the 90 degree corner and drill a 1” hole (he 1-1/2” mark being the center) for the tuyere. If you cut the template from 1/4” or thicker steel you can weld 4x6” plates on the six inch sides and have a fire pot. I have done this, adding a 1” rim and welding the tuyere in at a 5 degree down slope. 
I have found this shape and size to be efficient. A 4” high wall 8”down each long side helps contain the additional  fuel to be placed over the stock. 
with this set up an electric bed Inflater bypassing about 1/2 the air forges up to 1” (I have pushed it to 1-1/2”) 

Thanks again for the tips and advice. I probably just need to devote a day to fiddling with it, the problem is that I am a recovering perfectionist, so when things don’t work the first time, I start to question and second guess

I was raised buy one of those, it still bites me in the butt some times. The original forge I posted here was the second addition, I started with an 11 inch deep box with the tuyere about 4” off the bottom. I had to cut down the sides to get down to the hot spot. This one was based on those experiments. I have progressed beyond this one as well. I am up to the mark IV.
I have built a side blast steel fir-pot based on what the have learned as well. I recommend if you are planning in building your own steel fire pot or side blast masonry forge you mock it up with a pile of dirt and experiment with the design first.

I hope that I don't raise my kids to harshly.

I have been experimenting with dirt/clay and fire brick. I think the firebrick might be restricting me, but I do like how firebrick is more permanent than dirt, but maybe I shouldn't be focusing on permanence while I am still trying to figure out the basics... 

More permanent that DIRT, you wear DIRT out!? 

Frosty The Lucky.

Sometimes it's hard being this tough

So true but it's better to be the hammer than the nail.

Frosty The Lucky.

Good 'ole Grady County dirt.

That it is, lol

even cast iron fire pots are consumables. I used the JABOD forges as a test bed to design a steel fire pot. 
 

    Thank you, you give me a great idea. Sand, wood, construction material ....etc. I have plenty.

I'm going to make something sand based.

I'll let you know, and photo of course.

Best, caboverde

Edited March 10, 20233 yr by Mod30
Remove duplicate paragraphs.