Vertical Forge

I often get questions concerning how to make a forge. Here's a new one I'm doing. This will be my main workhorse for forge welding. The fist one I built works, but I've learned a few things since then. the first thing you'll notice is that this is a vertical forge as opposed to the tube style of the other one. There are good and bad points for this. Bad is that heat treating long blades will be a pain. Good are that I can get a piece heated on all surfaces at the same time. This will be a smaller inside volume and only a single burner forge. I can run 10 psi out of a single burner and get the same heat as the larger tube forge, but use a lot less propane! Another comment I see alot is "I can't make a forge because I don't have a welder." Well, this one is being put together out of scrap metal with no welding. Enough rambling...onto the forge construction: The first two pics show the tube section I'm using. This is 14 ga stainless steel duct found at a scrapyard. It's about 14" diameter. I originally was going to make my first forge out of this, so it already has two burner holes cut in it. I want an over all height of about 18" for this forge, so I'll have to piece it together from this tube section. You can see the lines I drew on the tube for where I want to cut. I'm using a cheapo central forge angle grinder with some cut-off discs to cut the steel. The 3rd pic shows the sections cut apart. I still need to cut the top section so it's an even, flush cut and not the rough torch cut that was on the original duct work. the fourth shows everything evened up. You can see I have about 18" of height. When I laid it out, I marked it so my single burner hole was about 1/4 up from the base. Next, I cut out a section for where the front door will be for the forge. Having the forge in two sections actually made this part much easier. Then, I did the rear opening on the opposite face. I used a cross style so I could put wide flat pieces in in different orientations without having to have a giant opening to lose heat through.

Now, I joind the two sections. I used a 2" wide strip of scrap stainless and riveted it to each of the sections. I used solid rivets, but you could use small screws. I then took the tube, set on some flat sheet steel and traced around the inside. Here, I'm using a beverly shear to cut out the circle. You can use a jigsaw, or any other means to cut the circle out. be sure to put a mark so you know how to orient it on the tube. They are never a perfect circle! Now, fit it to the tube and see if you need to grind or cut any metal off to make it fit. When you get it to fit, attach it. I'm using tabs and rivets. You need at least five of these. I probably should have used about seven for this diameter tube. If sheet metal heats up too much it will warp and you could get gaps along the seam. Minor gaps will be filled by refractory. In the last pic, I've poured a 1" base of refractory cement. Well, it's almost done now. You can see the progression in the pics. About all I need now is to attach the lid. You don't want to make the shell permanently fixed, or you'll have a bear of a time when the lining eventually needs to be replaced. By hinging the top or bottom you can easily access the entire interior. You can see here the forge with the interior coated and cured with Satanite. It's been fired after drying using a large propane torch assembly and is ready for spraying with ITC-100. To do this, I'll mist it to dampen it the use a compressor and a modified sand blaster to spray on the ITC-100. I'll fit the lid and add bells and whistles such as handles, a rest shelf and base legs after this. Then it will be time to insert the burner and fire it up! Oh yeah...I'll be going back over a few key points wth a welding machine. I built it with the use of one and it could be used as finished. BUT, it would be pretty dumb not to go over it since I di have one. Besides, a metal shop without a welder is blasphemy! For heat, I will use a 3/4" venturi burner (Ron Reil's burner site) and a 0.032 jet (MIG welding tip). Refractory lining is 2" of Kaowool with ITC-100 coated on thick. The floor has a mix of castable refractory and satanite. I will also have some pearlite/cement/clay mix put on to help slow any flux from dissolving the base. The Kaowool, ITC and gas valve are the most expensive items. Since I have many forges/furnaces, I buy these in large amounts and usually have them on hand for projects. Well, it's done now...kind of. Here's the pics of it now. I'm adding in a shelf in front to hold the workpiece and one in back where I can mount a small vise for doing twist projects while still in the forge. The top is held on with screws so I can clean it out or replace refractory periodically. I can also use it as a small crucible furnace for melting bronze and even cast iron. The first pic shows the ITC-100 going on over the satanite and cerwool. Note the high technical application process! The next pic is "trimming" the burner port tube. I had already gone back and welded it up before checking the fit of the burner. No problem...that' what a bandsaw is for! Just be sure you catch the forge when the cut is made! Next, is the forge up and running. The lid hasn't been screwed down yet in this pic so I used a firebrick to hold it down. The last pic shows the interior after about 5 minutes at 8 psi. I had to go back and coat the burner flare with some satanite and ITC-100 since it was about to hit "dripping" temperatures!