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Side Blast Help


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After a little over a year with the gasser, I decided I wanted to build a solid fuel forge. I have never used a solid fuel forge of any kind so I could use a little help with some dimensions. Yeah, in hind sight I probably should have made a JABOD first, but I'm already into this project. I decided to build a side blast with a water cooled tuyere based somewhat on Mark Aspery's design. I'm using an old tank that is 30" diameter, I already have one side cut and a plate welded back in to mount the bosh/tuyere to. So, here's my questions.

1. How far should the tuyere extend into the forge? Mr. Aspery made his 16" long which put it in the center of the forge. It feels like that is too far in, would 8-10" be too short?

2. Currently my outer pipe is 3 1/2" and my inner is 1 1/4." After I had this welded together I saw were he said to use 2 1/2" pipe for a hand crank blower, which I plan on using. Is my 1 1/4" inner pipe going to be too small?

3. How far above the forge floor should the center of the tuyere be? I plan on making it adjustable and I would like to burn both corn & coal.

4. How tall should the sides of the forge body be? I currently have them at 10" and it feel like that might be too high.

I don't like cutting stuff apart and fixing, so I would like to get this as close to right the first time if I can. I've seen some info from Mr. Stevens and other on here and it doesn't match up completely with what Mr. Aspery has in his article.

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Some of this sounds like you asking us what size shoes you should wear---it's based on you and what you plan to do with it; which we don't know. There is a big difference between a forge suitable for forging anvils and one for doing arrowheads for instance. Also WHICH solid fuel will you be using?  Coal and Charcoal have different air needs.

I sincerely doubt that you can make the "one true forge" the first go having never used one before.  I suggest you work on doing an experimental forge that allows you to change things around and see what works best for YOU and then make the "improved" version. This is why the JABOD gets suggested as a starter solid fuel forge as it allows changing depth, size, tuyere location/size, fuel types, blowers, etc fairly cheaply and easily.  I've been forging 39 years now and my forges still change from time to time as my needs change or I come up with a new idea. (For one thing, my travel forges need to be lighter and more easily loaded these days...)

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Mr. Powers. I did state my intended fuel source of coal and corn. From my limited understanding corn and both types of coal can be used by modifying the trench size & depth. I believe Mr Aspery uses his design for his classes on basic forging, which is my intent as well. I understand that each design has it's limitation which I will work around as I currently do with my gasser.

I'm sure several members has built similar design, but I have not seen many dimension other then what Mr. Aspery provides in his article. I'm fine with modifying the fire bowl to fit the project, but I don't have a lot of spare time to rebuild the whole forge. My assumption is that if I leave enough room below the tuyere and around it I should be able to adjust to a wide range of projects assuming I have the air flow. That's why I was questioning the pipe size. The general consensus is 3/4" is fine for a JABOD, does a water cooled tuyere make that much of a difference that 1 1/4" wont work?

It will have a steel frame base, so it's portablity (is that even a word?) will be limited to were the skid loader takes it.

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Mr. Powers - no worries, it’s easy to miss small things. I’ve been here long enough to know you need to give details like that. 

I D & F - Yes, I’ve looked at that thread, and some others. I may have missed it, but all the ones I’ve looked at seem to be lacking dimensions. 

I was thinking about Mr. Powers earlier post when I was out in the shop working on the base. I came to the conclusion that there are two main types of people on here, the guys that will keep on tinkering with a forge until it’s perfect (or have 10 forges) and the guys who will build one forge (or two for a second fuel type) and just make what they have work. Unfortunately I fit squarely into the second group. A forge it more of a vehicle to get to were I’m going for me (hot steel)

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Well their is different solid fuels, mainly charcoal and coal. Charcoal likes 3/4-1” tuyere wile coal, depending on how big a fire ball you need will be happy with lager. 

So if you plan on working 1” or smaller stock a 1” tuyere is sufficient and will be happy with both coal and charcoal, but if you want to weld 4” stock you need a bigger tuyere and coal or multiple tuyere and charcoal. 

Mad to how far into the box to put the tuyere depends on the size of the box and we’re you want the fire. You do not poke the tuyere into the fire, you fill the box with infallible material and the tuyere is flush with the side of the depression the fire lives in. 

What one misses looking at a side blast coal forge in operation is that their is a lot of fill under the fuel banked on the hearth. Your not looking at a 30x60” box filled 8” deep in coal. Your looking at 7” of fill with a bowl scooped out just in front of the tuyere and an inch of fuel on the hearth that you can pull into the fire.

charcoal is different as if you try to bank the fire with a fuel reserve you will have all of it alight. You manage the fires differently.

  I take it you didn’t see the tuyere and realty below hearth recommendations chart I posted?

dose it make sense now, or has my explanation just muddied the waters?

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Mr Stevens. Thank you for your reply. Your post which you linked above, and the chart is one I have referenced in the past. For some reason it never clicked until just now that chart references tuyere OPENING size and SUPPLY pipe. Do you think my 1 1/4" supply pipe will be large enough or should I cut it out and put in a 2"? My tuyere opening is currently 3/4" but would be easy to drill out to 7/8" or 1"

You did not muddy the waters with your explanation, I do understand the concept of modifying the fire bowl and the fill material required. 

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