Everything Mac Posted May 9, 2013 Share Posted May 9, 2013 Hi guys, I'm building a bottom blast forge at the moment and I've been doing a lot of reading on the clinker breaker vs grate argument... The general consensus is that it doesn't matter, but I read one thread on here suggesting a shaped clinker breaker was a useful secondary control on the air flow which is rather interesting. So this begs the question is a moveable "clinker breaker" (either an uppy downy or roundy roundy) worth adding as an extra air control over a stationry grate with holes. If so would you suggest an up/down movement similar to the forge Daniel Lea shows in one of his videos, or a triangular shaped breaker that spins round and round? As it stands I'm at a point in my build where I can do either. I like 01tundra's design of the fixed hole which is slightly raised. If I went for a fixed version I'd be copying this design, but I'd make it removable so that it can be easily replaced with another drop in unit as and when it burns through. I'm probably just reading too deeply into it all, but I'm offshore and have a bit if time on my hands. Much appreciated Andy Quote Link to comment Share on other sites More sharing options...
Bob S Posted May 9, 2013 Share Posted May 9, 2013 Holes in the bottom (as most firepots have) will guarantee that as clinker is formed, it will flow down and block off your air supply, which will make necessary a clinker breaker. A better idea (IMO) would be if the bottom of your fire pot was raised so that there was room for the clinker to form without blocking the air. Imagine a ball cut in half with a hole thru the center for air. This could easily be forged and welded in place. Your fire will be able to breathe without continuously 'breaking' the clinker and losing fuel in the process. When the clinker gets so large that it blocks the hole it can be removed from the top using a hooked poker. Read Tom Allyns comments here..... http://www.iforgeiron.com/topic/23205-fire-pot/ Quote Link to comment Share on other sites More sharing options...
yesteryearforge Posted May 9, 2013 Share Posted May 9, 2013 I like the triangular slightly egg shaped clinker breaker that comes in the better commercial firepots. I think you can purchase them seperately from the guys that sell the firepots. I have a Buffalo Railroad firepot that has had nearly daily use for around 20 years and its still in good shape. Quote Link to comment Share on other sites More sharing options...
petere76 Posted May 9, 2013 Share Posted May 9, 2013 Gents, Is there a benefit to mounting the commercial clinker breaker with the flat side up or the edge side up? We have a forge with the flat side on the fire side and the edge side on the air side. No appreciable air loss and the forge works well enough, just wondering if there is a consensus for mounting in a particular direction. Peter Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 9, 2013 Author Share Posted May 9, 2013 My questions still stand gents. I'm leaning towards having the inlet raised rather than having a clinker breaker design. But the idea of an extra control over the air flow is appealing. Cheers Quote Link to comment Share on other sites More sharing options...
Bob S Posted May 9, 2013 Share Posted May 9, 2013 My questions still stand gents. I'm leaning towards having the inlet raised rather than having a clinker breaker design. But the idea of an extra control over the air flow is appealing. Cheers If you read #18 in the thread I linked to above you will see that Tom Allyn was experimenting with different hole arrangements/shapes to change the shape and size of his fire. Tom was using easily available pipe fittings. If you try it come back and let us know how it works. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 9, 2013 Author Share Posted May 9, 2013 If you read #18 in the thread I linked to above you will see that Tom Allyn was experimenting with different hole arrangements/shapes to change the shape and size of his fire. Tom was using easily available pipe fittings. If you try it come back and let us know how it works. Bob I don't think you get what I'm asking. It isn't practical to build one design and then completely rearrange it for the sake of experimentation. Especially as I have zero experience with a bottom blast in the first place. I have nothing to compare it to... My question is "is a movable clinker breaker worth using as an additional control over the air flow by using it in different positions, over a stationary air inlet?" By using pipe fittings in that thread you linked me to, one does not have immediate control over the fire. But what I'm reading on clinker breakers on here is that their relative position has an affect on the fire... We have established that a raised air inlet is superior to a simple hole in terms of the formation of clinker and its subsequent interaction with the fire... As said in my original post I would build something using this design. Andy Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 9, 2013 Author Share Posted May 9, 2013 This is what I mean by a rotating clinker breaker. Apologies for stealing the image from here. And here in Daniels video you can see the other style I was referring to, which uses an up/down motion. http://m.youtube.com/watch?v=mj7OO2UX7MU As you can see, Daniel says that the position of his clinker breaker also regulates the fire. Whereas with a stationary air inlet you don't get this extra control and somewhat immediate control. I'm just wondering if this control is favourable to having the clinker gather around your raised inlet... I'm over complicating things I'm sure... Edit: this is the thread that got me thinking http://www.iforgeiron.com/topic/13373-clinker-breaker/ Cheers Quote Link to comment Share on other sites More sharing options...
Bob S Posted May 10, 2013 Share Posted May 10, 2013 Bob I don't think you get what I'm asking. that happens a lot.... :unsure: Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted May 10, 2013 Share Posted May 10, 2013 I started with a Buffalo tuyere "valve." It is slightly elliptical in cross section and has the rectangular hole through the center. The 1/2" round actuating rod extends toward the operator and has a short right angle bend for the handle. When the handle points downward, the hole is vertical. With the handle pointing sideways, each side opening gives more air, but the central hole is blocked, because it's sideways. One can get a bigger fire with less blower effort in this side position, but its value is negligible. not all that effective. In fact, I still have one Buffalo in my shop, and I welded a scrap iron weight to the rod opposite the handle, so that the handle always points downward. This gives a compact intense heat about 4"-5" above the tuyere. This is good enough for me. By rotating the handle a little on occasion, it helps a to keep fly ash and a bit of clinker from the fire. However, one must need to fish clinker out from the top every now and again using a fire rake or clinker fork. I've made these rotating tuyeres out of 18 wheeler truck axles, each axle averaging 2" in diameter. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 10, 2013 Author Share Posted May 10, 2013 Cheers Frank, much appreciated. Quote Link to comment Share on other sites More sharing options...
01tundra Posted May 23, 2013 Share Posted May 23, 2013 Mine has been working great, no air flow problems even when forging for 12 hrs straight and doing several forge welds. And my fire is always easy to maintain. Mine is a Schedule 40 2-1/2" pipe cap with anti-seize on it, when I want to change it I simply unscrew it by hand. I originally made three caps, one I cut three slots in it with the plasma cutter and another that has a single 1" hole drilled in it, but the one with the 1/4" hole array has worked so good I've never had a reason to try the other two caps I made. Quote Link to comment Share on other sites More sharing options...
rockstar.esq Posted May 23, 2013 Share Posted May 23, 2013 My fire pot looks like a less attractive version of o1Tundras. I have a 7/8" hole drilled in the center. It makes donut shaped clinkers which are easy to pick out. Prior to that I had a trailer ball that I'd cut roughly triangular and mounted on a spindle. Whenever it wasn't stuck it was collecting fines and plugging up the works. I've heard that cast iron clinker breakers are better- I think the raised inlet solution is much better. Based on your question I'm guessing you're using some kind of powered blower. I found that restricting air flow is more of a problem than a solution for me. When I used an electric blower I found that motor speed control was much better than trying to choke the air flow. High-speed low-volume air flow combined to give me a very weak fire. A slower speed with moderate volume gave me a controlled and hot bed of coke. I may not be explaining this well but in the end I went to a box bellows so I could save coal, quiet my forge, and better control what was going on. Of all the things I've learned here, the raised inlet pipe was probably the coolest. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 24, 2013 Author Share Posted May 24, 2013 Cheers for the replies guys. I am once again offshore so the project is on a bit if a back burner for the next couple of weeks until I get back ashore and find time to get to the scrap yard. I'm still undecided on my design though the raised inlet does seem like significantly less work. Not to mention less complicated. Cheers Andy Quote Link to comment Share on other sites More sharing options...
EricS Posted May 24, 2013 Share Posted May 24, 2013 Emac, I built a clinkerbreaker for my pot and its triangular it can be seen here http://www.iforgeiron.com/topic/26575-first-day-on-new-forge-build/ I think i get different results from the different position, point up i think I get a smaller more concentrated fire ball versus the flat side up the fire ball is spread out more. Think of the way the air would flow around the shape. I hope this helps. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 25, 2013 Author Share Posted May 25, 2013 Cheers Eric. An excellent forge you have there. I'm no closer to making a decision on the final design so I think I will just play it by ear when I finally get a chance to work on it I. A few weeks. Cheers Andy Quote Link to comment Share on other sites More sharing options...
humphreymachine Posted May 25, 2013 Share Posted May 25, 2013 I have an older forge with the triangular clinker breaker but it had a steel ring around it which was convenient to rest a permanent grate upon. I do not use the clinker breaker to regulate air flow and try to leave it straight up so that the air flow is symmetrical. I use a hand crank blower even for heavy work so varying air flow is easy. With an electric blower I’d use a variable speed control switch and or a gate in the air duct. My first two grates were cast iron disks with clusters of air holes but they soon cracked from the heat. I then went to a circular piece of half inch thick steel plate with a central 3/8 hole and six to eight 3/8 holes clustered around it. It works very well although the fire cement which I sealed it with has cracked allowing air to escape under it which encourages the fire to spread horizontally. I really need to fill the entire void between the grate and firebox wall with refractory cement. Clinkers do form but are easily removed with an L shaped poker. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted May 26, 2013 Author Share Posted May 26, 2013 Thanks Humphrey, a very informative post. Quote Link to comment Share on other sites More sharing options...
Rhettbarnhart Posted May 27, 2013 Share Posted May 27, 2013 Mac,I just built a forge, so far i just have 3 pieces of 14in. Square bar welded over the air hole. So far this Has worked great and every hour or so I just scoop out the clinker so no problem there. As to air control I have a hand crank blower so I can control air volume there. I suppose a triangle clinker breaker would help u control the position and size of the fireball though.. Rhett Quote Link to comment Share on other sites More sharing options...
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