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12 hours ago, Fowllife said:

Corn is around 390,000 btu per bushel. A bushel is 56 pound which is around 7,000 btu per pound. It wouldn’t be too hard to figure out the cost per btu for different fuels. On the commodity market corn is around $3.50/bushel right now.

I just took a moment and did the math, and it's pretty interesting. 

First of all, most smiths aren't going to be able to buy bulk corn at commodity pricing. I did some quick Google-Fu and found a bulk feed supplier selling whole corn for $205/ton. Tractor Supply Company also carries 50 lb sacks for about $6.80.

I just paid $12 each for three 50 lb bags of bituminous coal at Yoder's Blacksmith Supply. It's hard to get consistent numbers for bulk, but let's say $400/ton.

Bituminous coal runs about 11,000-15,000 btu/lb. To keep the math simple, I went with 14,000; that would assume that coal has approximately twice the btu/lb as corn.

If you divide and multiply all of that out, bulk feed corn and bulk bituminous are pretty close in btu/$ (68,293 and 70,000, respectively). In sacks, coal beats corn (58,333 vs 51,471), but it's still the same ballpark. Bulk coal is the clear winner, especially if you can get a better price ($350/ton brings the btu/$ to 80,000; $250/ton puts it at 112,000 -- which is exactly the same as commodity-priced corn).

Of course, you do have to factor in shipping or delivery costs. There's a TSC right next to where I do a lot of my grocery shopping, while the only time I can get to the Amish place is on my way back from taking my daughter to or from college. Factor in the convenience, and that can bring those numbers closer together.

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When you are using corn you are actually using corn charcoal; now how many BTUs are lost in turning the corn to charcoal? Same thing for coal; you have to coke it to use it; so comparing "raw" BTUs is not a good comparison unless you can compare them in using form or are able to quantify the conversion requirements.

Now comparing BTUs for coke and charcoal does make sense as they are in using form.

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That would put us in the 1950s and earlier, which would be at or before the Green Revolution, where expanded use of fertilizers and pesticides lead to huge increases in crop production. Before that, I suspect that corn would not have been as widely available or as cheap, and thus would presumably have had no advantages over coal or charcoal.

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Yes, corn (or any other agricultural commodity) has never been as cheap as it is right now when adjusted for inflation. In the past it would have been much more expensive then the more common fuel sources. I'm sure it might have been used small scale by people that just had it laying around.

JHCC's cost break down and TP's further adjustment probably still pushes the cost effectiveness even further out.

Just to throw another set of number out, I sold my corn last fall for around $3.25/bu or around $115/ton. That was after hauling it 10 miles to the closest elevator. For the OP and myself, this makes corn a little more of an attractive option. 

I would gladly sell corn right now for $200/ton off the farm in bulk 1,000 pound plus quantities.

This thread now has me wanting to make a solid fuel forge to go along with my gas just to try it out with corn. 

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You could always bring some down here, and we can try it out in mine!

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On 1/25/2019 at 8:48 AM, dave in pa. said:

I have used corn as forging fuel many, many times in several different forge set-ups.

Hey there Dave! Thank you for the detailed thoughts.  I have played with a charcoal forge but never tried to use coal.  Point:  you are telling me things I need to hear, that would go without saying to most others on here.  I appreciate it a lot.  And yes, I will be very willing to pick your brain only so long as you're willing to answer...especially like this.  Thanks again.

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Thanks Dave.  I'll start now if that's alright. Lol

Last night I threw together a small JABOD with a small side blast 1/2 inch tuyre and a small squirrel-cage blower (43 cfm I think).  The corn coked up nicely, and stuck together forming larger chunks.  I realize a half inch is pretty small, but would that be the source of the issues I had controlling air flow?  Or would I require something that can push air at a little pressure?  It seems (is it called water pillar?) that kind of air would blow the kernels up out of the fire.

Anyway, I'm trying a few different things to try and figure out a good firepot design.  

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The term you want is "water column".

Controlling the blast is always a good idea, and there are a number of ways to do this. With a manual blower or bellows, it's easy: just vary the rate of cranking/pumping/whatever. With a motor-driven blower, you have a number of choices: change the speed of the motor by varying its power supply, changing the air input, blocking the air output, and diverting a portion of the air output. There are a number of electronic options for the first, but you have to get the right kind for your particular motor. For the second, you can put an adjustable plate over the air intake, but be careful: some motors require air flowing through them to keep them from overheating. The third can be accomplished by putting some kind of gate mechanism between the blower and the tuyere. For the fourth, you leave a gap between the blower and the tuyere and adjust the blast by changing how directly the blast goes into the tuyere. Make sense?

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1 hour ago, Aubrey said:

Last night I threw together a small JABOD with a small side blast 1/2 inch tuyre and a small squirrel-cage blower (43 cfm I think).  The corn coked up nicely, and stuck together forming larger chunks.  I realize a half inch is pretty small, but would that be the source of the issues I had controlling air flow?  Or would I require something that can push air at a little pressure? 

Aubrey, it might be worth trying a larger size tuyere before anything else.  If the opening is too restricted then you might not get the flow you otherwise could, and the air velocity might be too high as it exits the tuyere.  Moving up a size in pipe might get you adequate airflow while still being 'soft' enough to not blow the fuel out.

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Aubrey,

I would move up to a 3/4 or 1 inch pipe.

Then, find a way to control the air blast as was said above.

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2 hours ago, JHCC said:

Controlling the blast is always a good idea, and there are a number of ways to do this. You leave a gap between the blower and the tuyere and adjust the blast by changing how directly the blast goes into the tuyere. Make sense?

Yes makes perfect sense.  So I dont need a high volume blower then? I have one but haven't used it yet...

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Sometimes things work the way we plan, but oftentimes some experimentation will be required.  Compare the small tuyere to some larger ones, and if it doesn't seem like its getting the job done, THEN move on to the bigger blower.

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Dave HojPoj and JHHC...and anyone else.

I just realized my phrase about controlling the air blast wasnt clear.  Apologies.  No, I have a damper on the blower so maybe control isnt the issue.  It didnt seem like enough air was getting to the fire.  I was able to maintain a hotspot about the size of a large apple and that was barely hot enough to forge with.  I suspect this had something to do with the half inch pipe as Dave mentioned.

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49 minutes ago, HojPoj said:

Sometimes things work the way we plan, but oftentimes some experimentation will be required.  Compare the small tuyere to some larger ones, and if it doesn't seem like its getting the job done, THEN move on to the bigger blower.

Okay I'll do that.  The problem with the bigger blower is that it's A LOT bigger.  140cfm to 43 bigger.  Lol  experimentation is exactly what I'm about, before I go into a major forge build.  I appreciate all the input.  I'll throw some pics at ya'll when I'm able to.  I'm sure that'll help.

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If you disconnect the blower from the air pipe going to the forge you have ZERO air.  A gap of 3-4 inches is a good start.  Aim the blower sort of toward the air pipe and you get some air, aim more directly and you get more air. Adjust as needed.

It is all about performance.

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No, don't buy another blower! Tinker with the one you  have, it already puts out more air than you need, it's plenty. When trouble shooting change ONE thing at a time and test. Keep notes of what you did and what happened. If you change more than one thing at a time you'll never know what did what, changed conditions can change results geometrically so two things changed might change the results by a factor of 4 +/-.

Frosty The Lucky.

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Thanks for the advice Frosty! No I wasnt planning to buy another one.  2's a crowd they say.  I'll step up the size of the tuyere first.  Probably 1 inch. 

So the firepot...for a 1 inch tuyere is there a rule of thumb for firepot dimensions?  Charles R. Stevens posted some drawings some time ago on tuyere sizes but if it had anything on pot dimensions I missed it.  Or does the firepot matter only in relation to the size of work?

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After reading Dave's post on 1/25 I decided to try corn in a demo the next day.  Made it a part of my, " You don't need ..... to begin smithing" talk.  Forged a pair of tongs, everything worked well. The fire tinder kept the fire pot packed and the blower throttled back. No one at the meeting had ever seen it done before. The demo can be viewed on Youtube at AFC Athens Forge. https://www.youtube.com/watch?v=GfBKfUgFFkI

Al

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Thanks a bunch for going through the effort, David!  That's quite helpful!

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I second that thanks!  Dave's video was insightful, and I'm still in the process of watching Al's.  

Al, I noticed the guy tending the fire seems to have been pretty busy doing it.  Was this much work on the fire actually needed or was he working the corn around in a bid to get it all coked up?  I ask only because it makes me wonder how well the fire does for those couple of minutes each heat you're away from it.  

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From my experience with corn, I'd say the guy was looking for things to do.

A corn fire can be fiddly but its not going to go out while you're working the iron on the anvil as long as you have some air going to it (a lot like anthracite that way), even working two or three pieces at a time. Push the cold piece in, poke the fire a couple of times, grab a hot pieces and go back to the anvil.

Heat, beat, repeat.

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Hi Aubrey, He was looking for things to do. But he is a very good "fireman". Dustin did most of the fire tending while we were doing the Kuhn Ring project, and never let a single peace burn! He has also helped me in several classes while I was recovering from shoulder surgery. Al

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