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I Forge Iron

To have a Fire Pot or Not ?


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Hi All,

Like so many others I am building my own coal forge

Actually I will be using coke not coal (I'm in the UK)

Some of the designs I see on the net have fire pot, others just have a flat 'table'.

I know I've seen a discussion somewhere on the advantages and disadvantages of a fire pot compared to the flat table, but now I want it I cant find it.

Can anyone give me a link, or give me your own preferences (and why)

Many Thanks


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Seeing as how you are in the UK, I think you should look at a side blast forge. I think they work great! Mine has been working better for me then the other bottom blast forges I have used.

Of the ducks nest forges I have used, one didn't have a fire pot and was basically on a flat table. That one bugged the heck out of me. Often there were 2 or 3 other people trying to heat iron at the same time, so the space was crowded, and it was hard to get the fire to do what I wanted it to. It seemed like if I was working it alone (which I never was) then maybe it would be better, as I could shape a pile of coal/coke and not have other people disturb it. Often I would get frustrated though, since I could not push a piece down into the fire. The other ducks nest I use regularly has a deep fire pot. Which can also be a drag. It gets super hot and is easy to weld in, as long as you are only heating the ends of a bar. If you want to heat a section one or two foot past the end (xxxx 6 inches even) then you are out of luck. A lot of time the hot part of the fire is below the table surface.

I haven't had any of these problems with a side blast however. I highly recommend them.

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Lonepine, flat table forges are usually associated with the common rivet or as some call them farm forges that have no firepot, they were made that way as they are cheap to make. Flat bottom forges that work well are usually of the side blown or English style.

This picture shows a cross section of one in use. Take note of where the piece to be heated is positioned.

In a forge with a fire pot.

The Blue area is an Oxydizing fire and if the work piece is shoved down in this area it is subject to a lot of oxygen as the air is just entering the fire and the work piece is more suceptible to burning.

The Green area is more or less a Neutral fire as most of the oxygen has been burned off and only Very Hot Gases are producing the heat.

The Black area on top is more of a carbuerizing fire.

Hope this helps you.




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hi, I'm also in the UK and the use coke breeze. Both side blast and Bottom blast forges work well. A colleague of mine reckons that bottom blast is more economical of fuel and is easier to maintain a small fire. I have used more side blast forges than bottom blast, but I am just now to build another forge with bottom blast.have you got any plans sorted out? What are you going to use as a blower? what sort of facilities have you got for building one? if you need any help I can probably give you a few pointers. If you are just starting you will probably be working with fairly small material and probably won't need a huge forge, but there are several things which need careful attention to avoid a lot of frustration.

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Hi H&T

The blower is from Axminster. Have used it on other peoples forges & its good
Search Results

Plans ?
something like this one...
Student Forges in the Shop of Donald Stanley

But without the brick top and with low (circa 1") sides to the table.
Probably will have a fabricated fire pot, unless this thread leads me to abandon the fire pot.

Facilities ?
Reasonably equiped machine shop, just no forge yet!

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what's type of forges have you used so far? Axminster fans are fine producing the volume of air but have no facility for speed control. Though a good many people do operate units like this it is desirable to control the airflow not only with an air gate but also with motor speed control. The noise from a blower running at full speed all the time is significant and becomes very wearing. The alternative is to site the motor in a different room and pipe the air through the wall. Or you can build an insulated box to house the fan.

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In the past I have only used side blast forges, (which I like), hence my basic question about bottom blast ones.

I have a window of oppertunity to spend a couple of weeks smithing full time (normally its a spare time hobby on other peoples forges). A side blast will take a bit longer to make than a bottom blast & I'd rather be smithing!

Towards the end of the year I will make a side blast as well. Youngest son wants to learn the craft and it will be much less stressfull not to share a forge with him!!

I agree the blower will be a bit noisy. It will go in a box like we use for mobile generators, so wont be a long term problem.

Thanks for your interest.

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hi john i also live in the uk.
I have built a number of forges and have found that if you build a side blast forge you will need ideally a water cooled tueyer i would sugest building a bottom blown forge and making a steel grate out of 12 to 16mm rod . you will find it more economical to maintain in the future. also if you make the base out of fire brick it should hold up to most of the heat exposed to the table.

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A side blast forge is most likely the simplest and quickest forge to build.
Blueprint BP0238 Side Blast Forge
BP0232 Side Blown Demo Forge

A bottom blast forge can be built quickly also.
Blueprint BP0133 The 55 Forge

I have built and used both of these forges. They are not permanent forges, but are serviceable while you get the forge you want built. Do not try to over engineer simple as it is just a way to get started. Construction time is measured in minutes.

Be sure to cover the sharp edges of the metal. If nothing else, cut a 2" wide section (ring) of metal from the drum, fold it in half and place it over the sharp edge.

More forge information on forges can be found by clicking the link below
LB0003 Blacksmithing Forges

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Where I 'help out' we use coke and run bottom blast forges. Both work pretty well and we end up with the classic donut of clinker after the fires gone out. Chances are Mike the coke was a bit poor or the airblast hole was too small. We've run those forges all day without undue stress and have only had to clean out the fire once or twice during the day. Personally I'd go for bottom blast if you haven't got a water cooled tuyure to hand (or a nice Allday & Onions forge) as they're simple to make and they work. Go for a decent sized forge table with a raised lip to keep the coke from dropping off the edges as you rake stuff around and to help keep your stock from falling out. Say three feet by two feet, with a 1 inch lip. That way when you fill the table with coke your not having to poke the stock into the fire at an angle and the coke won't just roll off.

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  • 2 weeks later...

hi, I like many others it seems am also building my own forge. I also have a question about firepots. I like many others made my forge from scraps of plate i had lying around my delovnica. My problem is getting hold of a firepot. I am in Slovenia and getting anything here is a problem. I thought about using a brake drum like so may others but it is going into a company workshop and i need something solid and not 'its an old brake drum' comment from a work inspector. I ended up using 5/16 and 1/4 plate to make the fire box. There is also a 1" layer of fire bricks to cover the entire top making the firepot 3" deep. I know this is not good set up as the mild steel will rot but how long can i expect a firepot like this to last? What affect is there to the welds? Here are some pics its not totally welded up up yet but i'll finish it on monday.


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Nice work Freb. I have a coal forge made of 1/4" with no covering at all. There is some rust and scaling but it is still solid after several years. I don't believe you will have any worries for several years yourself. i have learned on a previous forge though that cooling off the forge with water and leaving it in the forge overnight speeds up the degradation.

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