steponmebbbboom Posted September 24, 2007 Share Posted September 24, 2007 hello everyone. i have a champion 400 forge with a new aftermarket firebox. this firebox is made of cast iron and is bolted to the bottom of the original flange on the forge body. in the hours i have been working with this forge i have found the fire never seems to come high enough and i am wondering if it is because the flange on the body sets the top of the new firebox a good inch and a half down, and its flange is over an inch thick itself. so the clinker breaker is a good eight inches down? i think. perhaps more. well how deep should my firebox be? i can mill either the firebox or the flange to bring it up higher, but i cant bolt the firebox in from above as the opening is too small. thanks for any input. Quote Link to comment Share on other sites More sharing options...
Ian Posted September 24, 2007 Share Posted September 24, 2007 I'm sure others will step in with their own 2 cents but I think you might try building a bigger fire first before you start chopping things around. I've personaly worked in a bottom blown fire that was at least that deep if not deeper and all I has to do was make a bigger fire. More coke/charcoal/coal burned up of course but then feul consumption wasn't that much of an issue for me at the time. There was about 30 tonnes of coke outside to play with You might try filling in the firepot a little with firebrick to bring the 'bottom' of the pot higher up, or maybe try clay for the same effect. Make sure your clinker breaker still turns freely afterwards of course. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 24, 2007 Share Posted September 24, 2007 My big "RR" forge was designed to have the firepot dropped in from the top and the firepot sat on a layer of firebricks that both protected the forge bottom and brought the firepot more in line with the cutouts on the side. You can have a firepot that is too deep; a friend of mine once used a Semi brake drum to build a forge and with the tuyere at the bottom he had to bend stock into a hairpin shape to get it down to the hot spot. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted September 24, 2007 Author Share Posted September 24, 2007 thats what im finding Tom, i can hump on that blower all day and never get beyond dull cherry until i dip the iron about an inch down. im using bituminous coal, piled about two inches over the opening, cant get the fire up less than an inch and a half below the opening. to respond to your comment Ian i have considered using refractory mortar to bring the bottom end up but i cant see it staying in place long without cracking or lifting, and of course the clinker breaker is now that much further down and the shape of the firebox is now different, and refractory mortar is not that cheap. of course milling the firebox and flange isnt cheap either. in any case i have to do something as i am wasting a lot of fuel trying to get my iron hot. thanks for the advice. Quote Link to comment Share on other sites More sharing options...
mike-hr Posted September 24, 2007 Share Posted September 24, 2007 You may just have a choked fire. As you spin the blower, take a small diameter (3/8") piece of steel and gently lift the fire down by the bottom of the firebox. Does the sound change from not much, to a roar? You may have to give the fire a bit of a lift each heat until you figure out the personality of the forge. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted September 25, 2007 Author Share Posted September 25, 2007 Mike, i lift the fire by rotating the clinker breaker. generally it helps quite a bit with airflow but does not bring the fire high enough. i also dig clinker out of the fire periodically and feed coke from the outside in as the green coal is burned down. thanks for the response. Quote Link to comment Share on other sites More sharing options...
Glenn Posted September 25, 2007 Share Posted September 25, 2007 Photos would go a long way in letting us help solve this problem. If the fire pot flange is designed to sit on top of the table, and you have bolted it below the table, the sweet spot of the fire should be in the same relative depth in relation to the fire pot. You would now have to angle the metal DOWN to get to the sweet spot in the fire pot. Clinker depends on the impurities in the fuel and the heat of the fire. If you want clinker, get a good fire up to welding heat and throw in a double hand full of dirt and sand. It WILL produce clinker and will most likely block the incoming air. When hot clinker has the appearance (in my forge) of a plastic goo, that retains heat when you pull it out of the fire. Cold it looks like ash and some melted glass mixed together and has a noticeable weight to it. Depending on the amount of fuel you burn and the heat of the forge, you may have to clean the forge often (every 30 minutes or so). Or you may only have to clean the forge every 3-4 hours. When the air way is clear and free of obstruction (rocks, slag, clinker etc) the fire should be able to roar when excess air is blown in to the fire pot. Each forge fire has it's own personality. My forge starts to get fussy when the air holes fill with clinker. Just let the forge cool a bit, and the clinker solidifies and you can hook it out with a poker. You don't have to tear the fire apart, just reach to the bottom and hook it out. Then add more coke and a little air and your back to forging. The fire gets fussy when the volume of ash covers the air inlet in the twyere. The ash just needs dumped if that is the problem. If excessive clinker seems to be a problem try BP0138 Bullet Grate or a side blown forge. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 25, 2007 Share Posted September 25, 2007 When starting a new fire---no coke from an old one. I can get a layer of gooey fused coal that forms over the coke and strangles the fire. I have to take the poker and lift it up to provide air paths that will bring the fire up as the chunks totally coke up. With my new coal that it very finly crushed all the fines will choke the air paths until they coke together and I can lift them up. Every forge, every fuel has it's own particularities. Before making any major changes get a smith in to look at what's happening and your methods of work. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted September 25, 2007 Author Share Posted September 25, 2007 thanks glenn and tom. unfortunately my camera was stolen shortly after the firebox was mounted so they will have to wait. the original firebox was clearly designed to mount to the forge body in a specific way. the opening in the forge body is smaller than the flange boss under the opening. so it appears the original firebox was inserted into this recess. my replacement firebox can only sit on the bottom of the flange boss, so when assembled, looking into the opening, you can see a channel shaped hollow running around the interior perimeter. this is why i think the firebox is too low. unfortunately the upper flange of the new firebox just does not have enough meat on it to have a notch cut around the perimeter to bring it far enough upward. i think going this route, some of the forge body flange will have to be milled, and a smaller notch routed around the firebox to bring it up. regarding clinker, after a couple hours of forging i typically only get a handful of clinker all told. most of the time the biggest clinker i find when the coke cools is no bigger than a macaroon and only once when i forged all day long i pulled a clinker the size of a calzone from the firebox. the quality of coal i am getting is quite good. and i always jiggle the breaker until the fire roars. i have never accumulated enough ash to block up the tuyere. it would be nice if i could find a quicker way to separate ash and clinker from coke before firing up---i hand separate at the moment but i digress. i really need that fire to come up. thanks again. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted October 6, 2007 Author Share Posted October 6, 2007 hey all, was curious if any of you have a champion 400 forge with original firebox that could weigh-in or perhaps point me to some pictures? i didnt see any in the gallery... thanks. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted January 12, 2008 Author Share Posted January 12, 2008 glenn, tom; i finally have some pictures of the firebox and tuyere as mounted to the champion 400 forge body. the firebox and tuyere are made by newton forge & foundry right here in hamilton, ontario. Quote Link to comment Share on other sites More sharing options...
blksmth Posted May 21, 2008 Share Posted May 21, 2008 The fire pot looks normal to me. I do not know what kind of a fan you are using, but the fan could be the problem. Is it the blower that came with the forge? What ever kind it is, it might not be able to develop enough pressure to blow through the coke etc. Radial fans like in the larger old hand crank blowers should work fine unless there is a problem with the fan such as loose blade, missing blades, etc. If you fill the fire pot with coke (no fire) and crank up the blower, you should be able to blow the coke right out of the fire pot. It shouldn't be much different when you have a fire going. With a good fan/blower, you should be able to generate a forge fire that extends several inches above the fire pot. I don't think the fire pot is the problem. It looks like as good of a fire pot as can be bought. Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted May 21, 2008 Share Posted May 21, 2008 1. the supposed clinker breaker is not a clinker breaker, but an ash gate, blast director, most of them have the ability to alter the air flow from small to large or even to one side. 2. the way the fans are made on hand cranked blowers they will generally put out more air one direction than the other, try cranking the blower the other direction. 3. is there a lot of crud built up inside the blower fan housing, lots of crud creates friction loss, so the blast is diminished. 4. it looks like with some grinding on the bottom edge of the forge bottom it might slip into the hole. it looks to me like the strengthening flange is back aways from the actual bottom of the forge on the underside. my 4 cents worth. Quote Link to comment Share on other sites More sharing options...
Daryl Posted May 23, 2008 Share Posted May 23, 2008 It appears the firepot is bolted to the hearth from below. This would make the overall depth of the firepot about six to eight inches - putting the 'ball' of the fire below the level of the hearth (explaining why you need to poke the iron downward into the fire to gain any heat). If possible, try to lay the firepot into the hearth from above. This would make a small three-quarter to one inch high lip on the sides to deal with; though the fire would gain about two inches in height. Assuming your air supply has no restricitons along the pipe to the grate, the Champion 400 Series should easily provide an adequate blast. Now when making your fire, the ball will now be noticeably higher and fuller. If afterward, you require a deeper fire for a specific project, try banking in the sides with four by four inch angle iron layed with the bent edge up (this will save having a wide pile of coal to deal with). Quote Link to comment Share on other sites More sharing options...
civilwarblacksmith Posted June 5, 2008 Share Posted June 5, 2008 In my smithy at the Union Mills Homestead, the forge itself was built 25 yrs ago. It is a colonial style forge and had a brick fire pot that was the length of a brick deep (7"-8"). Under that it had a duck nest tyuere with clinker breaker. I tried using it that way but when I put air to the firepot, the fire seemed to drop deeper into the the bottom of the fire pot. We had to use a piece of clay pipe over the air blast and then surround the pipe with clay until it was at least 4" from the top of the fire pot to be able to heat the metal. The depth had alot to do with the problem. RebThe Civil War Blacksmith Quote Link to comment Share on other sites More sharing options...
matt87 Posted June 5, 2008 Share Posted June 5, 2008 What fuel were you using, Reb? Quote Link to comment Share on other sites More sharing options...
Ian Posted July 18, 2008 Share Posted July 18, 2008 Deepest forge fire I've worked was with Moony in Oz, that was an old truck rim with refractory to angle the sides. Must've been nearly a foot deep from the hearth table to the air grate. We filled it woth coke and it would happily burn with the sweet spot above the hearth table, mind you the blower was a big old thing that could float a tennis ball and we were working big stock. 30 tonnes of coke to keep the fire going was only a short wheelbarrow and shovel ride away Quote Link to comment Share on other sites More sharing options...
civilwarblacksmith Posted July 18, 2008 Share Posted July 18, 2008 Sorry Matt, Must have missed the e-mail on this. I was using soft bituminus coal out of southwestern West Virginia. Quote Link to comment Share on other sites More sharing options...
mustang 12 Posted August 9, 2008 Share Posted August 9, 2008 hi steponmebbboom,i built a firebox awhile ago from i/2 inch plate and i found it was slightly to deep the heart of the fire was to far down the pot it was costing a fortune in coke ,have made this insert that sits in the bottom it brings the bottom so the pot is only 3 1/2 inches deep .doesnt seem ta be any air leaks down the sides ,getin a real good usefull fire,well i dont know if* its any help only thing i found withit the other day was i might have drilled a few to many holes for the air ,well idont know if its any help Quote Link to comment Share on other sites More sharing options...
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