juicaj1 Posted July 10, 2011 Share Posted July 10, 2011 So I had built a converted bbq grill into a forge and tried it out for the first time today burning some charcoal and I got it going and turned the leaf blower on and it started getting nice and hot. After a little while though I looked on the ground under it and their was splattered melted steel. It turns out the bottom of the grill was melting away. Can anyone tell me what was wrong with my setup that made this happen? The first picture is of where the grill began melting. The second is my air intake/ ash disposal that ended up falling off because of the metal melting. Quote Link to comment Share on other sites More sharing options...
southernforge Posted July 10, 2011 Share Posted July 10, 2011 Too much heat (plus) no insulation (equals) burned out bottom. Try a layer of concrete. this tends to explode when used in forge setting, use a refractory like Fire clay instead. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted July 10, 2011 Share Posted July 10, 2011 "Claying" may be the answer. 3 parts sand 1 part portland and optional 1/2 part clay (kaolin) add just enough water to bind, it should break instead of smushing. Pack this in to protect the metal and form a good shape to work with. Let dry overnight and fire it up. I suspect the BBQ is aluminum and not steel. The liquid metal would be rather bright white/yellow if it was steel. It would probably have sparkles coming off too Phil Quote Link to comment Share on other sites More sharing options...
juicaj1 Posted July 10, 2011 Author Share Posted July 10, 2011 Yeah I'm pretty certain that it's aluminum. The fire couldn't have been hot enough to melt steel for as long as I had it going. (which wasn't even long enough to get 1 decent heat)I thought about the clay idea and I really like it next one I'll probably try and use some. What is portland? Quote Link to comment Share on other sites More sharing options...
pkrankow Posted July 10, 2011 Share Posted July 10, 2011 . What is portland? The active ingredient in concrete. It comes in a bag at your home improvement store, and you look/ask for a broken bag so you get a severe discount since you only need a few cupfuls and it comes in a 80# bag. Phil Quote Link to comment Share on other sites More sharing options...
Old N Rusty Posted July 10, 2011 Share Posted July 10, 2011 Just looking at the pics I am sure its AL. try a magnet. do you like, and want to keep this forge? find a steel plate to put in it under the cement liner Dont use CONCRETE it will explode use the sand/ cement mix. Good luck! Quote Link to comment Share on other sites More sharing options...
juicaj1 Posted July 10, 2011 Author Share Posted July 10, 2011 I'll look for that portland stuff. I'm going to scrap the grill part I'll keep the other parts like the stand it was on but I'm just going to look for a new thing to use. Quote Link to comment Share on other sites More sharing options...
MattBower Posted July 11, 2011 Share Posted July 11, 2011 Regular concrete does not stand up to forge temperatures, and as ONR said it can spall dangerously at high heat. (The chemically bound water gets liberated and turns to steam inside the concrete.) Bad idea. If Phil says the claying recipe works, I believe him. But don't use regular concrete. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted July 11, 2011 Share Posted July 11, 2011 Regular concrete does not stand up to forge temperatures, and as ONR said it can spall dangerously at high heat. (The chemically bound water gets liberated and turns to steam inside the concrete.) Bad idea. If Phil says the claying recipe works, I believe him. But don't use regular concrete. I got it from OnR a few weeks ago. I am using it on my brake drum forge to make it a better shape inside. One fire and it still looks new. You can also dig under the topsoil and use the clay from your yard, but it will shrink and crack. Phil Quote Link to comment Share on other sites More sharing options...
Robakyo Posted July 11, 2011 Share Posted July 11, 2011 The first picture is of where the grill began melting. The second is my air intake/ ash disposal that ended up falling off because of the metal melting. Greetings Juicaj1. I am most concerned about the second picture you posted. It seems that all of the pipe parts that you are using appear to be galvanized. Even the pipe flange! Also, in light of my recent readings, bottom blast is less efficient than side blast for charcoal. And welcome to IFI. Robert Quote Link to comment Share on other sites More sharing options...
MattBower Posted July 11, 2011 Share Posted July 11, 2011 I got it from OnR a few weeks ago. I am using it on my brake drum forge to make it a better shape inside. One fire and it still looks new. You can also dig under the topsoil and use the clay from your yard, but it will shrink and crack. Phil Bentonite kitty litter is a good, cheap source of clay -- and you don't have to worry about screening out the rocks and so on. It also will crack, although using a bare minimum of water and lots of inert filler (clean sand) helps a great deal. Quote Link to comment Share on other sites More sharing options...
MattBower Posted July 11, 2011 Share Posted July 11, 2011 Greetings Juicaj1. I am most concerned about the second picture you posted. It seems that all of the pipe parts that you are using appear to be galvanized. Even the pipe flange! Also, in light of my recent readings, bottom blast is less efficient than side blast for charcoal. And welcome to IFI. Robert Tuyeres are forced-air-cooled, and most of this one is far from being in contact with the fire. Formation of zinc oxide smoke (the stuff that causes metal fume fever) requires heating zinc to near or above its boiling point, which is around 1650 F. I have trouble imagining the tuyere getting that hot. Even the flange is exposed to open air and benefits some from forced air cooling. If one were really worried about it (I wouldn't be), an overnight soak in vinegar would strip the zinc from the flange. I have inadvertently burned zinc. It's quite obvious when it happens -- bright bluish flame, thick white smoke. If it somehow happens, don't stand there and breathe the smoke. Shut off the heat and move upwind. It's that simple. We're not working in brass foundries, or welding galvy all day. (Well, perhaps some of us are. In that case, wear a respirator and/or take other appropriate precautions.) Quote Link to comment Share on other sites More sharing options...
pkrankow Posted July 11, 2011 Share Posted July 11, 2011 Just pickle the parts that are getting close to the heat, overnight in vinegar or a few minutes in muriatic acid. Zinc is besset not messed with, but the pipe a few inches out of the fire pot will be unaffected because it is cooled by the air blast. Phil Quote Link to comment Share on other sites More sharing options...
Robakyo Posted July 13, 2011 Share Posted July 13, 2011 Tuyeres are forced-air-cooled, and most of this one is far from being in contact with the fire. Formation of zinc oxide smoke (the stuff that causes metal fume fever) requires heating zinc to near or above its boiling point, which is around 1650 F. I have trouble imagining the tuyere getting that hot. Even the flange is exposed to open air and benefits some from forced air cooling. If one were really worried about it (I wouldn't be), an overnight soak in vinegar would strip the zinc from the flange. I have inadvertently burned zinc. It's quite obvious when it happens -- bright bluish flame, thick white smoke. If it somehow happens, don't stand there and breathe the smoke. Shut off the heat and move upwind. It's that simple. We're not working in brass foundries, or welding galvy all day. (Well, perhaps some of us are. In that case, wear a respirator and/or take other appropriate precautions.) I guess that as a newbie, I am a bit paranoid where zinc is concerned. After reading various accounts about Paw Paw Wilson, a Smith of vast knowledge, I take heed. Also, even though his forge melted, it was determined to be aluminum. And certainly his next forge will have an insulating layer of dirt, clay, or other substance to increase efficiency as well as protect the forge body. I intended to mention the use of vinegar to strip the zinc, but alas, I found myself distracted as I am again at this moment. Well Juicaj1, best of luck with your next build.-Robert Quote Link to comment Share on other sites More sharing options...
juicaj1 Posted July 18, 2011 Author Share Posted July 18, 2011 Oh yeah I knew all about how it's not good to burn galvanized pipes and all that so I made sure I bolted the flange part on the underside of the grill so it never got any direct fire on it. I figured that and the constant cool air blowing through it and that the heat from the fire was going up would make it pretty safe. Quote Link to comment Share on other sites More sharing options...
nhblacksmith Posted July 18, 2011 Share Posted July 18, 2011 So I had built a converted bbq grill into a forge and tried it out for the first time today burning some charcoal and I got it going and turned the leaf blower on and it started getting nice and hot. After a little while though I looked on the ground under it and their was splattered melted steel. It turns out the bottom of the grill was melting away. Can anyone tell me what was wrong with my setup that made this happen? The first picture is of where the grill began melting. The second is my air intake/ ash disposal that ended up falling off because of the metal melting. The best material for lining the bottom of a forge to prevent burnout is fire clay, usually available at a masonry supply dealer. Portland and other cements are apt to absorb water and can explode when the water is converted to steam. Fire clay is one of the base materials for manufacturing high temperature fire brick, crucibles, and refractory. It is obtained in a powdered form like regular cement and will last for years in a forge. As a safety note about concrete, never drop hot iron on a cement floor, especially if it is damp. Instead, keep a piece of steel off to the side to lay pieces on to cool. If you have ever seen concrete shrapnel from hot iron (I have), you won't soon forget it! Quote Link to comment Share on other sites More sharing options...
Humphry Posted July 25, 2011 Share Posted July 25, 2011 Welcome NHblacksmith, I've had good luck using refractory cement. If you're ever in the Lewiston/Auburn area the people at INFAB have all kinds of it. Various bricks of different strenghts too. I use the cement for furnace castings as well as lining the old Buffalo forge firepot. You might consider a big truck rim for your base, give you a good excuse to visit your local scrap metal man too. Allways a good day for me. Remember, life is like a box of chocolates. Let the world take another turn and try again. Quote Link to comment Share on other sites More sharing options...
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