Advice on what to order in new forge sought

[Momatt]

Hello, I’ve decided to add a coal forge to my kit after using exclusively gas for a decade.  I will be burning blacksmith or bituminous coal and will have a manual crank blower. I’m about to order from centaur forge and have four  questions that I would really appreciate your input on.  Now is my chance to get it just right and I’ll be living with it from then on.
 

1.) Fire pits are listed as coke or coal. If it’s a shape or volume optimized to burn one or the other I’d rather have coal.  If one is just heavier than the other I’ll order the heavier one.

2.)do you prefer a round fire pot or a rectangle and why?

3.) Do you prefer a sliding gate vs a ash dump and why?

4.) The hearth or platform are 24 by 30 inches and can be had with the pot oriented in either dimension. Is there a type of work that favors one over the other, maybe it’s just which fits your space in the shop best and doesn’t matter. 

thank you!

[George N. M.]

I have always used older coal forges and do not have any experience with the newer ones but I think they will be pretty similar.  With that caveat I will try to respond to your queries.

1)  IMO, coal and coke work about the same except that you need more constant air to the fire with coke.  In fact, if you are doing proper fire management you are burning coke in both cases because the coal cokes around the perimeter of the fire before being raked into the center.  So, IMO, go with the heavier one.

2)  I have never used a rectangular firepot but I think thefirewould tend to assume a round or circular shape with nothing much going on in the corners.  I think the shape of the tuyre would have more effect on the shape of the fire than the shape of the firebox.  I think that probably easier to manufacture a square or rectangular firebox than a round one.  Just weld 4 trapazoids together and there you are.

3)  I have always used a hinged ash dump and have had no problems.  I would think that a sliding one would have more of a tendency to bind up because it has a greater frictional surface.

4)  If you have a rectangular hearth and a rectangular fire box I would have the long dimension of the fire box oriented 90 degrees to the long dimension of the hearth.  That is because you are usually standing on the long side of the forge for easier access to the fire and if you ar putting long work in the fire it is usually oriented across the short dimension of the forge.  Some forges have cutouts on the long sides lined up with the fire box to allow long pieces to sit lower into the fire than the lips of the sides.

I hope this helps you in your decision.

You are not that far from Twisted Willow's location in Eastern OK.  You might think about contacting him to see if he might be able to sell you an older coal forge and blower for a lot less than a new one would run you.  I know he has a large stable of bloowers.  I am less sure about forges. I worked for years with just a small (about 26" diameter IIRC) rivet/farm forge and it worked very well and still does.  Just like anvils and hammers, don't buy more tool than you will realistically need.

"By hammer and hand all arts do stand."

[Momatt]

Thanks George much appreciated!

[Irondragon Forge ClayWorks]

I would call Centuar Forge with the same questions. I have done business with them in the past and they have always been very helpful when I had questions.

George covered them well. As far as a dump or sliding ash dump, I have used both and right now both of our coal forges have sliding (rotating) ash dumps. The only difference I have found is the sliding/rotating you swing it open then swing it closed after dumping the ashes. with the hinged ash dump you bump the counter weight up and after the ashes are dumped it will close on it's own.. The other advantage is if you have a build up of coal gas in the tuyer and it ignites the weighted ash dump will automatically open to vent the gas explosion. I'll send you a PM...

 

Edited January 29, 2023 by Irondragon ForgeClay Works
add PM

[Momatt]

Thanks !

[swedefiddle]

Good Morning Matt,

We put in 4 new Firepots, in Vancouver Island Blacksmith Shop, almost twenty years ago. We bought them from John in Hamilton Ontario. He makes them there, the firepots are about 1 1/4" thick. Yes, they are a little more expensive, but well worth every penny.

I would recommend working with someone else's Coal Forge before making such a commitment. There are so many variables and configurations.

When I put together our Portable Blacksmith Trailer "the Flyin' Forge", I took an idea from John Little in Nova Scotia. The burner is a piece of 3" black pipe, laying on it's side, with 5 pieces of - 3/4" black pipe, 3/4" tall, 3/4" between them, welded in a line. A threaded cap is on the outside end for clean out and the Hand Blower is connected with a piece of Dryer flex-pipe on the inside end. This is laying front to back in, like a wide V-shaped bottom (I made it from an old Oil Tank). Clinker, Ash and clay is laying around the outside of the pipe to make the center bed slightly lower just above the nipples. We use a large bolt(s) to restrict the air nipple(s) if you just want a short fire. The Clinker will build-up around the outside of the air nipples and will sometimes restrict your air flow, otherwise you pick the Clinker out at the end of the day. I made the collector of smoke, using the top of a large Hot water tank. Sometimes there is some side wind where we set up. We lay split bricks on their side edge to block the wind. It took a bit for our members to figure out how to use it. That was over twenty years ago, we still use them.

Neil

 

[anvil]

On coke, They work about the same so firepot makes no difference. The difference is how you manage your fire size, meaning a narrow trench or a full sized fire. With coal its managed with water and the "green" coal on the table. With coke, you need a couple of fireclay bricks that you would make from castable refractory. They are longer than your firepot and the combined width of both are wider than your firepot. These two bricks are then moved in and out to determine the size of your fire.

Round vs square. My firepot is rectangular and this is far better for general forging. Simply said, A rectangular pot means the fire is the same temp the whole length and width. This works great for bar stock, which is long. You can still put in "bent" iron on the diagonal and get a longer heat. 

A round firepot is far better for a farrier or horse shoe'r. Most horses have 4 feet   and you can put 4 shoes in the fire and get an even constant heat on all 4. A rounf firepot is smaller and lighter so, better for the portable farrier rig. 

For an ash dump, both work and are no problem. Design a handle to open and close the sliding dump so that it is convenient and in easy reach of your hand. It is a pain in the Ash  to have to reach under the forge to dump the ash.  I use a vertical dump, not a sliding type. 

Orient your rectangular firepot lengthwise and centered width wise in the center of your table, meaning you face the narrow side. The reason is you can better use your table sideways width on both sides to maximize the amount of coal on your forge. This is a real plus. So this means you face the long axis of your firepot, and the firepot lives along the short axis of your table. 

A couple stands are needed, but put them on your "when I need Them sometime in the future" list.

Depending on your forge, there is commonly found on the old cast forges a couple of eyes, one on each side of the opening to the firepot. These are for a much needed steel rest. This is like 3/8" round bar that is forged to fit the eyes and rotate up and down to be able to support longer steel when you are heating up an end, not the middle. It should have a leg that swivels that is long enough to reach the ground and support your work. When not in use, it hangs down and the swivel leg lives under your forge by the ash dump lever or handle.