Help with forge pot

[scottyp74]

Hey all, I wanting to build a forge pot. I dont seem to work anything bigger than 1 1/2 square or round stock. I am thinking of making the pot 8x10 and 3 1/2 inches deep. Would this be a good size fire pot to start with. The fire I have now is 6 inches deep and is 12 by 15. It eats coal like crazy. It is just way to big. What do you guys think????

[ThomasPowers]

Fuel usage is more often based on the blower you are using than the fire pot; but you can try it out by claying your big firepot to a smaller size and see how that works for you.

[Everything Mac]

As TP says, claying your current pot might be an option. Though 6" deep does seem excessive. I reckon you'd probably find the smaller design better for your day to day needs. 

All the best 

Andy

[SReynolds]

Go big or go home. I hear plenty a tale focussed about " my pieces burn up and the fire goes out quickly. 

Problem develop with a shallow fire. You don't need a fire pot at all but you need some depth to it so's your work isn't at the bottom and it goes out when you stop to take a (non alcoholic) beverage. 

 

[jlpservicesinc]

Coal or coke is a consumable fuel..  While yes a larger fire will consume more fuel a small fire or shallow fire while it can heat pieces of steel you never will get to achieve a fire  that uses all facets of the heat/ fire zones..  

The argument is raised now that a smaller, shallow fire can do the work of a larger fire.. I don't agree..  For most hobby smiths this might be the case as they don't mind hanging around waiting for a piece to reheat.

I want as fast a reheat time as I can get as long as it's a fully heated piece and not just on the outside..  A shallow fire on anything over 1/2" the heat cycles become to long for my liking.. Ideally even up to about 2" I like about a 2minute reheat time..  I use a shallow fire only for tempering.. 

If you lower your air input the fuel won't get used up as fast as will proper fire management.. 

anyhow, If you really want to get the best of both worlds make an adjustable firepot.. make it out of thick plate with a telescoping side.. It can be messy to change all the time but can achieve what you are talking about..   

 

If you really want to experiment.. You can make a coal ash and cinder lined pipe tuyere forge.   The pipe has several hole on top of the pipe.. the clinker and ash is packed in around and above the pipe in the shape of the desired firepot..  Add salt to the cinder/ash mix as a binder helper.. 

You simply put the blower on one side and a plug on the other.. No reason to fill the holes on top as the only ones exposed at the ones not covered by the ash/clinker/salt mix though if you run a strong blast you will want to plug them.. .  3" pipe, space the 3/4" holes about every 2" IIRC.. up to the size of the firepot you think you would want.. 

FYI..  a firepots depth should put the Neutral atmosphere at or about the top edge of the firepot itself burning the air enough to make a stoichiometric fire zone at that height.. 

so, to much air will make it an oxidizing fire, not enough and it becomes a carbonizing fire zone.  A shallow fire will mainly have an oxidizing fire as the fire has excessive 02 and the air above it adds to the effect.. 

 

One other thing..  Coke pieces inside the fire also dictate what kind of fire you are creating..  Soft coal fired forges are a skill set in their own right.. Fire management has a lot to do with the results achieved.. 

 

[Charles R. Stevens]

Drop a 3" pipe cap with a 3/4" hole drilled in the center in your fire pot, this will ineffect make your fire smaller and shallower. It will also make the "dragon poop" easer to remove. It's called a bullet grate. If you need deap and wide again pull it out.