Making a new forge... options?

[A.McPherson]

Hi folks!

So I came across a chunk of 12 or maybe 14 inch(i didn't measure) pipe about 4 ft. long, and I'm thinking of making a forge out of it. I'm planning on making it a blown horizontal, mainly for heat treating and a bit of light forging. I do plan on making it electronically controlled some time in the future, but not right now.

Obviously the length is a bit of overkill, so I'll cut it down a bit...

So here's the question really. Should I go ahead with my plan, or should I do something different, like a vertical, since I've got this giant chunk of pipe? Oh, it's damn near a half inch thick...

 

[Stacy E. Apelt - Bladesmith]

The pipe is just a sleeve for the forge. It needs only to be strong enough for welding on a few things and supporting the refractory. A really heavy pipe is more problem than solution. At 1/2" thick, it sounds like cast iron ( another problem). Schedule 80 steel pipe is as thick as anyone would ever want. You can literally roll sheet metal into a tube and screw it together to make a shell.

Things to consider in planning a forge:
Mount it on a rolling cart - the welders carts at HF and similar places are perfect for mounting a forge. There is even a place on the back for the tank to store. Your HT tools and tongs can store on the shelves below the top.
Length of blades being HTed - the forge should accommodate the blades with several spare inches.
Diameter - all you really need is a few inches clearance to do HT. A 4" chamber is enough. Larger is OK, but it takes more fuel to heat. 6" is good for most HT tasks. If your pipe is too large, you can add more layers of insulating wool, or line it with firebricks to reduce the chamber size. The bricks can be held in place by metal bands, and then covered with a layer of satanite. Cover this with 1" wool, and the normal interior refractory coatings.
Type of burner - Blown is best for HT.
Thickness of insulation - 2" wool by all means if it fits.
Number of burner ports - you can have them every 6" if desired, but a well laid out forge of 12-16" can easily run on one burner. Two is all you would normally need for a larger HT forge.
PID control - you can add the PID later, but consider the controls needed for the gas when planning and building the basic forge. Putting the main parts in now makes for a simple conversion later. At a minimum, install a "tee" before and after the flame control needle valve. Plug the side holes for now, and you are all set to add the second stage later.