marcusb Posted May 23, 2012 Share Posted May 23, 2012 I am currently outfitting my shop and have decided to construct a permanent forge attached to my chimmney. The problem I have ran into is that there is tons of info on coal forges, both in construction and operation and almost nothing dealing with charcoal. Is there anyone on here that uses charcoal on a large scale in there forge? I am wondering if I should just scale up a coal design by the density factor to achieve similar results. Thru experimentation I have found my fire must be both larger and deeper. any info would be much appreciated to save me mistakes. Quote Link to comment Share on other sites More sharing options...
Ridgewayforge Posted May 23, 2012 Share Posted May 23, 2012 I think, IMHO, that you would do it pretty much the same as coal, though charcoal burns quicker. A deeper fire might be a little better for this reason. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 24, 2012 Share Posted May 24, 2012 NO! do not design a charcoal forge as a larger coal forge! Since all the charcoal contiguous with the forge fire will burn you want to keep the amount not actually in the using part of the fire down while increasing the depth of the fire as much as possible. When I use a coal forge for charcoal I build up side walls from firebrick to make more of a trough forge keeping the fire deeper and not having it spread to the sides where it's putting off heat and burning up fuel but not being useful. One of Alexander Weyger's books had a picture of a charcoal forge he had seen in his travels that had a large adobe V shape built into it to funnel charcoal down into the firepot but control it as well. Charcoal also does better with a hand crank blower or bellows than electric blowers. I started with home made charcoal back in 1981 and still use it for medieval LH forging. Quote Link to comment Share on other sites More sharing options...
marcusb Posted May 24, 2012 Author Share Posted May 24, 2012 Ok, thanks for the advice. I did happen on to a little info in a book I am reading today I will run by here hopefully it may help others with similar ambitions. It said for welding with charcoal, build the fire at least 12" deep and cover it with metal to trap the heat. SO it sounds like I need to design something with a deep trough like firepot at least 12". Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 24, 2012 Share Posted May 24, 2012 You might search for examples of lively forges as a starting idea but with the capacity to pile charcoal deeper on it. Is welding going to be a common goal for your forge? Getting a good reducing fire is partially a factor of fuel size as well as air input. Rehder in "Mastery and Uses of Fire in Antiquity" has a bunch of info on biomass fired furnaces and in his experiments the reducing zone in a bloomery was about 12-13 times the mean fuel diameter so there is a balance between charcoal so small that it burns up too fast and charcoal so large that you can't get a reduction zone. Note that the Japanese size all their charcoal to about 1" cubes for use in smelting and forging. Quote Link to comment Share on other sites More sharing options...
marcusb Posted May 24, 2012 Author Share Posted May 24, 2012 Thomas, I would like to have the capacity to weld large stock if needed. I already have rivit forge to frustrate me, I would like to build a forge that have the capability to handle all my shop needs as I grow it. Stock size will increase as I add a power hammer etc. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 24, 2012 Share Posted May 24, 2012 Then you probably don't want to do it with charcoal. Wanting one forge to do it all is like wanting a vehicle that will seat 16 people, haul 2 tons of coal, handle sportily and get great gas mileage! Quote Link to comment Share on other sites More sharing options...
marcusb Posted May 24, 2012 Author Share Posted May 24, 2012 How many forges should I plan for? I have a Champion 401 rivit forge currently, it seems to be a good match for small projects. If I build a large sationary forge with additional capacity, is there another type I am not aware of? Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 24, 2012 Share Posted May 24, 2012 What size and how many forges, anvils, etc. etc. is something we all deal with. Trying to decide in advance how large some tools need to be before developing a line of products can lead to costly mistakes. A solid fuel forge can be very simple and require no special materials to speak of so there's no reason to just make what you need when you need it and decide as you go. Seriously, how large a piece of iron are you going to be able to work at one time? For the most part not a lot more than 3-4 X will fit under your hammer except for bending. I've made the make it before I know what I need mistake many times in my life. At present I have three coal forges, one is a nice little 12v farriers forge I've never lit, one is a cast iron rivet forge I've used fairly often but seeing as it hadn't been clayed it's got a crack more than half across it. (that's how I got it) Then there's the beauty I built, it's 36" wide x 50" long with a hood that doesn't draw. I've used it quite a bit and it works well but it's really big. Then there's the forge I use almost exclusively the variable volume propane forge. I guess the gist of what I'm trying to say is don't lock yourself into equipment till you know what you'll actually use. You'll be a while learning the craft anyway. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
JamesG Posted May 29, 2012 Share Posted May 29, 2012 I would make a sideblase forge somthing like the japanes.Use firebrick and fire motor for your comple rows and on the back goes as high as you would think, the rest loose stake for you can move the bricks around to fit your work. I have a bottom blast forge and I burn charcoal, When I forge weld in it I can go about 2 hours before I need to clean the air grate out . I am useing a cast iron showe drain. Good luck on your forge. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 29, 2012 Share Posted May 29, 2012 optimize for what you'll be doing the most of and then make arrangements for outliers---I once needed to box fold 3/8" plate several feet long so I dug a trench forge in my back yard---in the city! and built a tuyere from a piece of blackpipe that would give me a 2'+ working fire. Had to clamp a piece of RR rail up on some 4x4 uprights as the "anvil" and got the folds done to make a firebox for a replica of the Santa Maria. Quote Link to comment Share on other sites More sharing options...
marcusb Posted June 13, 2012 Author Share Posted June 13, 2012 Update! Picked up nearly 40 Refractory brick from a memeber on here, trying to decide if I should build a steel or wood frame. Currently plan to lay up corners with cement block, but to span/contain the brick im not sure Quote Link to comment Share on other sites More sharing options...
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