irnsrgn Posted September 14, 2009 Share Posted September 14, 2009 (edited) I know I am going to get some flak from this post, but here goes anyway. So called Clinker Breaker at the bottom of firepots. Is it really a clinker breaker? Just look at the one in your own forge, does it stick up into the firepot far enough to actually break up a clinker? Probably not. If you stop and think about it and look at some of the information from old publicatios, you will find it referred to as a tuyere, blast gate or ash gate. Due to the shape of their construction they were made to be used to control the amount of air entering the bottom of the fire, and could be manipulated to have a small center fire, a large fire with more air, or a fire off to one side. The Trinagular ones, with one of the V's corners is pointing down will give you a nice small even fire in the pot. If you rotate it to so that one of the V's is pointing to one side, you will get a little larger fire. If you rotate it so one of the V's is pointing up, you will get a really hot fire. The round ones with a slot in the center have the pivot rod offcenter. With the slot pointing up and the highest side up, you will get a nice small condensed firel. Rotate the slot to the side and you get a little larger fire, Rotate it so the highest side is down and you get lots more air around the sides and also up thru the slot for a large fire. When you rotate this so called Clinker Breaker during a heat, what are you actually doing? You are getting rid of the fine ash and small clinkers at the bottom of the firepot. You more than likely have at some time removed a Doughnut Clinker from your firepot, did you happen to notice that the center of the doughnut is open from the air blast shooting up thru it. The clinker material (impurities and residue from burnt iron) forms around the air inlet automatically being pushed to the side by the force of the air. Occassionaly if you are using exceptionally dirty coal when and the clinker has built up sufficient to overpower the air blast (2 to 5 Oz of pressure) the fire wil more or less quit and/or you idle the fire for a bit and the clinker molten ooze flows over the air hole , and upon restarting, you get no air. if you stick a straight poker down into the center and lift you get a good fire for a little bit. No matter how much or vigorously you rotate the air gate, so Called clinker breaker it doesn't do any good. forges with a plate with slots and no air gate/so called clinker breaker are high suseptible to clinker choke is what I call it when the clinker restricts the air to your fire. Side Blown or Back Blown forges do not suffer this problem as the clinker just pools or congregates at the bottom of the fire in front of the tue or Tuyere iron. I have been wanting to post this for some time now, finally got it off my chest so to speak. Now let the ranting and raving and name calling begin, but before you do just stop and reread this post and think about your own forge and forging experience. Respectfully, irnsrgn Edited September 14, 2009 by irnsrgn Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted September 14, 2009 Author Share Posted September 14, 2009 (edited) The below pictures are from a 1942 military technical manual I used for an article I wrote for our Prairie Blacksmith Newsletter many years ago. and this is a quick drawing I did to explain a Coal fire. The best tool to remove a clinker shortly after the air has been stopped is a clinker fork. Just slide it down the front side of the firepot and then slowly push it to the air gate and slowly lift and you may be able to bring the whole clinker up and out of the fire in one piece with disturbing your fire that much. Edited September 14, 2009 by irnsrgn Quote Link to comment Share on other sites More sharing options...
keykeeper Posted September 14, 2009 Share Posted September 14, 2009 Thank you Jr. I agree. I use an old Champion Whirlwind with the three slot arrangement, the only thing the "clinker breaker" reaches is inside each slot, but doesn't reach out enough to affect anything lying inside the air grate slots. The middle is not affected by any movement of the device. There is no way the clinker is touched by it. Most of the time, what clinker I get fall through the slots anyway with a little coaxing from the poker when I lift the fire after burning for a while. I have yet to find a sizable clinker in my pot. Luckily, I have a supply of good coal that doesn't form much clinker. Quote Link to comment Share on other sites More sharing options...
jeremy k Posted September 14, 2009 Share Posted September 14, 2009 Jr - I'll add what was told to me, and if that is true, then it may be of interest. Now this is not gospel. - I was told that as you tend your fire - you keep working green coal down from the sides of the firepot - so as to keep the coke moving towards the center and up to where the main part of the fire is burning. As the green coal gets closer to the main fire area it starts to coke and is the "fuel" that supplies the heat of your fire. If this is done - any "clinker" mat'l will be forced to the center, and - yes if the "clinker breaker" is rotated it will make that and the ash drop from fire pot area. This does make sence?, is it gospel???. I have seen many clinkers in the shape of doughnuts - yes - is that the result of the correct way of managing a fire???? I try to do this(force green coal from the sides "down" and still have a build up of some clinker in my firepot when done, although not as the "doughnut". If I just keep adding coal to the top of the fire - I get the donut shaped clinker. This I believe has to do with fire control and others that have been forging alot longer than I have will I hope include their input. What is that "correct proceedure??? - In my case I use a bottom blast brick forge. - I believe this will be a great thread for beginner smiths that use coal. - JK Quote Link to comment Share on other sites More sharing options...
double_edge2 Posted September 14, 2009 Share Posted September 14, 2009 only used coal for a couple of years, and did get the big doughnut clinkers, till the old bloke from over the back came over and had a play. his periodic playing/feeding, left no large clinkers, and i learnt fire control, and what the stupid key/handle, spinning thingy was. he said, ant lion nest, keep the cone clean and the lion fed. no more lge clinkers when i got used to it. Quote Link to comment Share on other sites More sharing options...
Francis Trez Cole Posted September 14, 2009 Share Posted September 14, 2009 I use a grate in the bottom of my forges found I did not need it either the rivit forge that a lot of smiths use dont have clinter breaters. Quote Link to comment Share on other sites More sharing options...
thecelticforge Posted September 14, 2009 Share Posted September 14, 2009 I strive for the nice round clinkers. A little polyureathane and you have a dragon poop paperweight to sell. Quote Link to comment Share on other sites More sharing options...
Oak Hill Forge Posted September 14, 2009 Share Posted September 14, 2009 I agree that you rarely get clinker deep enough in the tuyere to "break" them up, but what I have experienced is that ash / fines sometimes obstruct the air flow causing a high velocity situation that will burn up your project like right now. Rotating the clinker breaker and opening the ash dump resolve this situation quickly. There seem to be lots of different designs for clinker breakers and I'm sure they alter air flow, and bust up ash differently. I'll try to get some pictures of the one I just built for my new forge as it's different than most. Quote Link to comment Share on other sites More sharing options...
Early Cuyler Posted September 14, 2009 Share Posted September 14, 2009 Dragon poop?...lol I save all mine as pets. Got bored with the rocks and I think the pet clinkers are much nicer to look at :-) Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted September 14, 2009 Author Share Posted September 14, 2009 Mounted on some kind of base, they make good Hard Luck trophies for people who have nasty problems getting to a meeting or missing one because of problems. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted September 14, 2009 Share Posted September 14, 2009 I use some really filthy coal so am something of an expert on clinkers (although that's probably not worth braggin' about...eh? ). The clinker formed in my factory Buffalo pot will completely shut off the air flow in less than an hour of continuous work so periodic half turns of the handle are necessary to drop a few cinders into the ash dump and let some air pass - but I have to stop and fish out the clinker anyway so I think a more appropriate term for the device is "clinker lifter" as the triangle or oval ball does have a tendency to raise it enough to be fished out with the poker...and BTW, my poker is 1/4" round rod with the tip flattened and curled slightly into a hook - very similar to your clinker fork but only one tip. Quote Link to comment Share on other sites More sharing options...
David Einhorn Posted September 14, 2009 Share Posted September 14, 2009 Apparently the firepots with clinker breakers seem to fall into two rough categories, those like the Champion firepots that have a grate between the coal and the clinker breaker and the pots like the Buffalo Forge pots where, at least with my pot, the coal sits directly on top of the clinker breaker because there are no bars between the coal and the clinker breaker. Interesting. :D Quote Link to comment Share on other sites More sharing options...
keykeeper Posted September 15, 2009 Share Posted September 15, 2009 Unicorn: The one I was speaking of has a half round depression in the bottom of the firepot, with the three slots. That part actually sits down into the top of the tuyere. The so called "clinker breaker" in it swings into the side slots, in a pendulum like action. To be honest, I like the ones like the Buffalo, where the fire is sitting directly on it. I think it allows better control of the blast, which allows you to have a fire either real hot in the middle, or spread over a wider area. Seems like that type makes a better "donut" clinker, at least the one at our assoc. shop does. I like pulling apart the fire, and fishing them out after we shut it down. Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted September 19, 2009 Share Posted September 19, 2009 If you're worried about semantics, just call it a tuyere valve. Quote Link to comment Share on other sites More sharing options...
gadetoz Posted September 19, 2009 Share Posted September 19, 2009 A great thread - thank you Irnsrgn Explains a lot of what I have observed over the past 6 months exploring the wonders of working with hot iron and fire management. In my case I do not have a "clinker breaker" but control the air in the tuyere air path with a slide gate valve before the air is delivered from the bottom of the fire pot (which is cast iron and about 5 inches deep). Based on my observations, coupled with this excellent thread I draw the following conclusions, regarding where I have gone wrong: 1. Too much air over the past 6 months (wrongly thinking hotter is better) - leading to sparklers or burn off at a critical moment and way to much clinker - based on the fact that I only burn coke 2. Make the fire much deeper and slow the air down - That is - take more time and slow down Once again - many thanks Trevor P.S. - I also keep clinkers as pets Quote Link to comment Share on other sites More sharing options...
keykeeper Posted September 21, 2009 Share Posted September 21, 2009 (edited) Since we've been discussing clinker breakers and such, I thought I would share this. Biggest clinker to date I've pulled from a fire, this one was created with one of the "rotating disc/triangular shaped" type clinker breakers in one of our associations shop forges. This took about 3 hours of forging to make, note the hole in the middle, this was all one piece but broke when I pulled it and cooled it off. Approximately 5 inches across, never slowed the fire down one bit, just kept rolling away from the blast into this nice donut. I worked the "Clinker breaker" several times while managing the fire. Never saw any clinker in the ash bucket. Enjoy. I'm kinda proud of this one....LOL. Edited September 21, 2009 by keykeeper Quote Link to comment Share on other sites More sharing options...
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