Keith Rider Posted October 17, 2012 Share Posted October 17, 2012 I'm working on my second forge, but it will be my first good setup. I need some advise on how deep I should make it. I read one article that said 7" from the workpiece to the tuyere with 2" of coal on top of the workpiece. Others on this board have said 4" between the work and tuyere. My forge is from a 10" deep drum, so I mounted the tuyere 2 1/2" from the bottom and will cut a pair of notches in the top to bring the work down a bit. The area around the air pipe is covered over with some heavy sheet metal so that I can pack clay all around and make the bottom slope down to the tuyere. How deep should I cut the notches? I'm considering cutting them down about 3" and welding ears on them so that they can be slipped temporarily back into place. Details - the drum is ~80 lbs, supported on a three leg stand made of angle iron and pipe, air pipe is 3" stainless steel, air source is a shop vac with a router speed controller. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 17, 2012 Share Posted October 17, 2012 One of my students built a semi drum forge and ended up abandoning it as he had no way to notch it and couldn't get the work piece to the hot spot. I'd say notch down to 2-3 inches above the tuyere---depending on the fuel which you didn't mention. For charcoal you can notch higher off the grate. When I made a brake drum forge I went the other way. I used a light drum and built a "C" shaped sheet metal fence to extend the walls up with the gap taking place of the notch. I also cut a mousehole opposite the gap at the hot spot height so I could push long bars through. If I needed to get large forms hot I could pull the fence and lay the workpiece over the top of the shallow brake drum and pile coal/coke on top of the place I needed heated. I could also lift this forge with one hand... Quote Link to comment Share on other sites More sharing options...
Keith Rider Posted October 22, 2012 Author Share Posted October 22, 2012 I ended up doing the notch with a power hacksaw and a grinder with a cutoff wheel. You only need to cut part way through on the bottom of the notch so that the cast iron will break off in a straight line. No problem. I ended up notching down to 5 1/2" above the tuyere - when I post the pictures you'll see why. There is a thick ring on the outside of the brake drum that I wanted to leave intact. The tuyere is a 9"x3" piece of a cast iron fireplace andiron. Given the dimesions you can imagine the size of the fire - huge. The only problem I had during the test run yesterday (other than a too big fire) was the massive clinker that formed way down under all that fire. I had to break down the whole mess to get it out. If I use 1/16" steel sheet to block off the ends of the tuyere and make a smaller fire is the clinker going to stick to it and make it impossible to get out? I was heating up 10 to 12" of 3/4" round on each heat, which is more than I can draw out before it cools off, so I want to shrink the fire down to only heat 6" at a time. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted October 22, 2012 Share Posted October 22, 2012 If you clean clinker out hot it tends to not be very sticky. It gets quite sticky as it gets to dark/dull red colors. Make a steel cap for your tue with a 3/4 inch hole in it and try that, just use a large pipe cap or a piece of heavy sheet metal. Having a table of some type intigrated into the forge is helpful for fuel management. The table does not need to be heavyweight as it is only supporting fuel and not fire. What is the inside diameter of your forge, and can you post pictures? Phil Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 22, 2012 Share Posted October 22, 2012 Restrict the area of the tuyere---clay can work and lower the air flow, sounds like you were shoving way too much air in. What are you using as a blower? Quote Link to comment Share on other sites More sharing options...
Keith Rider Posted October 22, 2012 Author Share Posted October 22, 2012 The ID is about 16" - it holds about 40 lbs of coal. I also build a 20"x14" table on the side so I do have a place to put some hot coke if I need to. The table is angle iron with a sheet metal bottom. The angle on the sides of the table is pointing up so that it makes a lip on the edge of the table to contain the coal or coke. The pieces on the table are the leftover andiron bits after I cut out the middle section to make the tuyere. The air inlet and ash dump are made from 3" stainless steel DWV pipe from a chemistry lab. It was supposed to be acid resistant, but it only works if you install it right. The contractor installed it with some low spots that collected waste and allowed the acid to eat through. The holes were small pinholes, so I brazed them up. The box with the knob on it is a router speed controller connected to a shop vac. The medium to medium-low range is about right. On full blast the thing looks like a volcano on the Discovery Channel. Project number one is a set of tongs. Before spring I need to figure out a way to repoint a plow. In between who knows what I'll do. Right now I'm just enjoying the sight of man's strongest materials bending to my will. Quote Link to comment Share on other sites More sharing options...
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