A sideblast fire pot

[Arthur210]

After a year using a JABOD forge (using charcoal), I decided to solidify make a steel fire pot. I was tired of having to reform the sides because they'd crumble.

So, inspired by the fire pot that Charles R. Stevens showed us in a different topic, I made my own.

I work mostly on small items (hooks, leaves, etc.), so I wanted a shape that would conserve fuel as much as possible. This is why I added a slope on the wall opposite the tuyere. A slightly more complex shape but the bottom is only 2" by 3", while the top is 5" by 10". Total height is 6".

First I made a cardboard mockup to be sure my plan worked:

Everything looked good, so I proceeded with steel. I used pieces from a wood stove I took apart last year. The plates are 3/16" thick. Should be thick enough to last me a good while, considering that I spend less than 10 hours a week.

Overall, it took me about 3 hours to cut the pieces, fit and weld them together. I immediately moved it into place in my existing forge.

I only had time for a quick test burn.

Worked well, although the sides are higher than what I was using by about an inch. It still took less charcoal to fill than the JABOD. Even better, it was much faster and easier to clean up.

I should be able to do more complete testing tomorrow and deteemine whether I need to shorten it a bit. Once that is determined, I may add a rim to finish it.

Cheers! Arthur

[Irondragon Forge ClayWorks]

Looks good to me.

[Charles R. Stevens]

 

What are you using for  an air supply?

 

[Arthur210]

Box bellows, about 2 cubic feet of air with every full single movement of the piston. The pipe is 1" diameter.

[Arthur210]

Full testing performed earlier today, and as I suspected the pot is a little too deep. I needed to either pile up more charcoal and pump more air than usual, or angle my steel down.

This will be easy to fix, by simply shortening the side of the pot. I will be doing that tomorrow.

[Arthur210]

Made the adjustment to my fire pot, lowering the short sides by about 1". I kept the long sides higher, as this will help keep the charcoal contained.

I tested it again and it's now at a good height, with the steel sitting right at the top of the fireball.

Last step will be to weld a flange around the pot. This will make it easier to push back the hot coals into the pot.

[Laynne]

Arthur210,

You say it took less to fill but when forging how does this type set-up compare to a JABOD for charcoal consumption?

Laynne

[Arthur210]

Hi Laynne!

Consumption is pretty much the same as a JABOD bowl of the same volume.

The main problem with the JABOD is that every time you use it, you tend to enlarge the depressinon in the dirt when moving the coals around. So if you are not careful and don't restore the bowl into shape, it grows and you end up consuming more charcoal. The steel pot solves that.

The other advantages of the steel pot is in the ease of cleaning and lack of vitrified clay/sand mixing up with the coals. At the end of my forging sessions, I shovel my hot charcoal into a cast iron pot with a lid that I leave outside the shop to cool (lack of oxygen and cold put it out and I can use it next time). This is quicker and easier with the steel pot, with its smooth sides. And I have no clinker mixed with the charcoal.

Essentially, I used the JABOD to experiment with the size and proportions of my bowl, and used that as a pattern for by steel pot.

Cheers,
Arthur

[Laynne]

Thanks for the reply. I have been toying with the idea of a permanent fire pot.

[thematrixiam]

Very cool. I like it. 

[Frosty]

Arthur: The disadvantage of a steel fire pot as you made is longevity. Steel in direct contact with a blown fire won't last very long. 

Fire pots are wear items, sure cast iron fire pots last long enough to be worth buying but steel burns if exposed to air. When cold we call iron combustion rusting. The hotter the faster it burns starting with scale as in when you pull hot steel/iron from a forge up to a sizzling shower of sparks. 

You've put a lot of thought and good work into your side blast fire pot Arthur but replacing the dirt in a JABOD is a LOT less work. Please don't stop thinking and trying things, it's what makes this craft enjoyable to so many of us and I sincerely don't want to discourage you. You did a good job, I just have my doubts it's a long term solution. 

Frosty The Lucky.

 

[Arthur210]

Hi Frosty! Indeed, I'm aware that the pot won't last forever and will burn out eventually. It will be interesting to see how long it lasts, considering that I spend less than 10 hours a week at the forge.

If it lasts a year I will consider it worth my time. Most of my forge sessions are about 2 hours, so the 5 minutes I spend reshaping the dirt before lighting up the forge, plus sorting out pieces of vitrified sand out of the charcoal, may make the steel pot a big plus. Or not. Time will tell!

Note that the steel is from the inner wall of a wood stove I cut apart, so I strongly suspect it is not mild steel (methinks it sparks too much for that). This may increase its resistance.

[Frosty]

Sounds like the steel fire pot is probably a good investment in time for you or folks in  your situation. I'll be very interested to see how durable it is. 

I've wondered about steel wood stoves myself but they don't get red hot unless you're doing it WRONG!   Our "Jotul" wood stove is cast iron with a brick lined fire contact zone but it cost us a couple grand installed; it has a lifetime warrantee and they came right out, and replaced the rope gaskets, painted and inspected the stove. When I called and asked about the rope door gaskets maybe leaking. We had to spend $1,700 to have the stove pipe replaced with triple wall fire proof. The stack carries a WRITTEN life time warrantee against ANY damage due to a stack fire.  If the stack creosotes up and the house burns down, THEY are liable for it ALL. 

We'd have to burn straight pitch for fuel to get a 3 burn zone Jotul to creosote a stack at all. It IS rated to burn coal, even the sub bituminous sold in the Interior or shaley anthracite sold locally. We have the company we bought the stove from inspect and sweep your stack every fall and they keep telling us we're wasting money but it's our money if we want it inspected and swept.

One year's worth of supplemental wood heat and the worst ever build up report was. "It isn't shiny and there was a total of two 3lb. coffee can's worth of non Flammable gray ash build up. 

Believe me I understand paying up front for value but I WANT that value. 

Enjoy the craft, its one of funnest things you can do with your clothes on. 

Frosty The Lucky.

[Arthur210]

Now a year later, and this morning I had to patch my fire pot. As expected a part of it wore out (or burned through). I estimate usage over the last year to be about 100 hours.

Since the damage was localized right above the tuyere, I repaired it by adding a thick piece of steel where the hole was. Almost 1/2" thick (cut from a rail tie plate), compared to 1/8" for the original plate. Took about 30 mimutes to cut and weld in place. That should last a while longer.

[pnut]

I was wondering how your firepot was holding up just the other day. I'd love to have a metal firepot but it's not within the capabilities of my tooling at the moment. A metal firepot I could just drop into a table would be wonderful. Oh well. One day soon hopefully. I'm glad it's held up so long. Making the whole pot from tie plates would be quite a robust firepot indeed. Food for thought.  

Pnut

[DennisCA]

I really like the design, it's similar to what I drew up in CAD though mine is for using coke or coal. I'm working with a JABOD and as you say it's annoying when the firepit looses it's cohesion and has to be reshaped. I did it last night again, I only get to forge one day a week though so it's not that big a deal.

Maybe next year I will have enough experience to know what size firepot I want and I can weld one up. I was considering water cooling behind the plate as well.

[Laynne]

Here's what I came up with. It's bottom blast using an inherited fire pot. I made the grate to raise the fire and used angle iron to form the trench. It took some experimenting to get the air flow right. I can go all day on less than five gallons of charcoal and still have the convenience of the ash dump. I was daydreaming and burned some half inch round in no time.

[natkova]

Well how you guys manage to find correct depth for your firepots  for longer stocks, or you need to forge lets say 2 foot stock at midle.  I have to place stock over fire then place more charcoal on it i feel like iam wasting fuel that way and far awaz from sweet spot.

 

[Frosty]

If you use a bottom blast fire pot you're stuck with what you have unless you go to lengths to make it so you can adjust the depth.

I usually use a bottom blast "duck's nest" forge rather than a fire pot. The duck's nest just a shallow less than 50mm. depression in the rammed soil bed in my rivet forge. The larger one I no longer use was more elaborate but didn't work better.

A side blast works really well across a shallow trench. Guys  keep making them deeper and deeper and having ever more trouble getting them to work. 

If you use a shallow depression or trench and need a deeper fire put a fire brick on each side and it's 50-60 mm deeper, stand the bricks on edge and it's 100-160mm deeper. Long stock passes through the trench between the firebricks. If it's too low in the fire put something under the stock and raise it up. You can make any shape, size or depth fire "pot" you need with firebricks around the duck's nest. 

I've been burning coal and occasionally charcoal, even wood this way for I don't know how long. 

I usually burn propane but there are things you just can't do in a propane forge, say make a tea cup size fire for delicate work.

Frosty The Lucky.

[Arthur210]

I use bricks on two sides of my firepot to contain my charcoal when I need to pile more on, as you can see on the following picture. For longer stock that I need to heat in the middle, I make a crack between firebricks on the far side so that the stock can pass through. When it is narrow enough, the coal doesn't spill anywhere. (I can take another picture later today showing the fire bricks on the far side if you want.)

If I had to do this often or with much longer stock, I would probably use a larger forge table, with more surface area. This would prevent coals from spilling too far and I could then rake them right back into the fire. Essentially it would be a trench between added fire bricks, with the fire in the middle.

But essentially yes, I am only heating up about 6-8 inches of steel at a time with my current setup. I could probably manage at least twice that long with a slightly modified configuraiton. For longer, I would need a different forge and tuyere.

[natkova]

On 3/22/2022 at 11:42 PM, Frosty said:

If you use a bottom blast fire pot you're stuck with what you have unless you go to lengths to make it so you can adjust the depth.

I done it like that today I bend my rim wheel so it make 2 inches shorter firepot I think it will be like trenches, trouble with having flst fireplace and bricks on sides is you blow fuel awwz its not contained aroun tuyere where it should be.

I didnt tested it yet but I cansay its realy shallow now , you can fit two pipes of 2 inches in it thats depth around 50 cm if I need higher I will cut wheel up more and I can alleays insert weld some metal plate or cut.it if.needed.

 

I didnt took photo today but I think i will.

On 3/23/2022 at 5:55 AM, Arthur210 said:

I use bricks on two sides of my firepot to contain my charcoal when I need to pile more on, 

You dont have issue eith furl being blown awaz from tuyere I used stove plate and it was realy "slippery" for furl and it got blown away easy.

And its frustration when you eant small forge but have to chase charcoal to get it near tuyere

Edited March 24, 2022 by Mod30
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[Frosty]

If you're blowing charcoal out of the forge turn the blower down. Charcoal burns best with a soft blast. Coal likes a stronger blast but you shouldn't be blowing either out of the fire. 

Maybe aim the blower away from the tuyere pipe going into the forge so the fire only gets a fraction of it's output.

Frosty The Lucky.

[natkova]

On 3/23/2022 at 5:55 AM, Arthur210 said:

I use bricks on two sides of my firepot to contain my charcoal when I need to pile more on,

You dont have issue eith furl being blown awaz from tuyere I used stove plate and it was realy "slippery" for furl and it got blown away easy.

And its frustration when you eant small forge but have to chase charcoal to get it near tuyere.

 

Before (one with clay) and after resize.

I made it shalower now.

46 minutes ago, Frosty said:

If you're blowing charcoal out of the forge turn the blower down. Charcoal burns best with a soft blast. Coal likes a stronger blast but you shouldn't be blowing either out of the fire. 

Maybe aim the blower away from the tuyere pipe going into the forge so the fire only gets a fraction of it's output.

Frosty The Lucky.

I noticed bellows or airmatress blower dont do it when there is slight depression in firpot, you can clearly se how it got contained in one place.

Edited March 24, 2022 by Mod30
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[Arthur210]

I don't have trouble with fuel blowing away, unless I am running low on fuel in the forge. When it happens, I just add a bit more charcoal (or a small piece of scrap wood) on top of the stock.

Note that I have angled the tuyere down a little bit (about 5 degrees). That may be helping. So is the fact that I am using box bellows. Charcoal likes a gentle breeze.

[natkova]

Well I dont want to be cheap guy around here but sometimes iam heating stock smaller than 1/2 " .