Hillbillysmith Posted January 10, 2008 Share Posted January 10, 2008 Check out what I just found on YouTube: :cool: [url= - Vogler-DVD: Rennfeuer auf der Dom Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 10, 2008 Share Posted January 10, 2008 Yes those are short shaft northern europe bloomeries and they are smeting iron from ore. I've been on a smelting team that built/used similar ones made from cob---no bricks. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 10, 2008 Share Posted January 10, 2008 Cob? A few of the guys in our group have been talking about trying to make a bloomery. Any tips? Frosty Quote Link to comment Share on other sites More sharing options...
matt87 Posted January 10, 2008 Share Posted January 10, 2008 Looks to me like a demonstration of various historic methods for reducing wrought iron from the ore. Notice the differences in sizes of the furnaces and the methods for providing a blast, as well as the size of the blooms they produce. All are basically the same design though: a vertical hollow shape where charges of charcoal, ore and flux are added periodically. Air blast is provided at the bottom. The liquid stuff is slag (like clinker in a coal/coke forge), not iron. At no point in this process does the iron become liquid (that's why the process is a reduction rather than a smelt). At the end of each reduction, the slag is tapped and the bottom of the forge broken open to remove the bloom. It is them consolidated by repeated heating to welding heat and hammering. This serves to make the iron one solid piece rather than the spongey object it came out of the furnace as, as well as driving out impurities. Quote Link to comment Share on other sites More sharing options...
Valentin Posted January 10, 2008 Share Posted January 10, 2008 Nice video !have not seen it yet thaks Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 10, 2008 Share Posted January 10, 2008 I have posted on this a number of times. I was a member of a team doing experimental archeology on Northern European Short Stack Bloomeries---the principals presented a paper at the IronMasters conference that was held in Athens, OH on the 10 years of experiments they had done, and that was about 10 years ago now IIRC! Our bloomeries ended up being cob after trying a number of methods, clay, clay and wattle, etc. The receipe we use is: 3 shovelfulls of silty dirt, 2 head sized bundles of chopped straw and 1 shovelfull of dry powdered clay, (bentonite from a feed store will work---we used to dig our clay out of a creekbed in the early days). Mix throughly with the absolure minimum ammount of water necessary to make what looks like dirty straw. We mixed by hand, ugh! To start dig an 8" or so deep round bottomed hole the dia of a 5 gal plastic paint bucket. Seat said bucket in the hole and start building a thick wall around it---note that keying it into the ground surface will help prevent a "leak" along the bottom edge. When you get up near the raised section of the bucket remove it and smooth down the interior---you don't want the charge hanging up during smelting. then replace the bucket near the top and continue up tapering the wall thickness slightly as you go up. repeat until you are about 4-5' high. We would leave an opening for the tuyere by taking 2 tin cans and removing both ends and building them into the wall slightly above ground level (end to end to get the length needed). We would also make a firebrick "door" into the bottom side to allow retreiving the bloom without knocking over the furnace. When done let dry overnight and then next morning, with the door open, start a wood fire in the furnace to help dry it out. Continue feeding it all day. As evening approaches build up the fire to preheat the furnace and start a charcoal heap in the bottom. When you are ready to run, close and cob in the door, put the tuyere into the hole left for it and cob any holes around it. Fill the furnace with charcoal and start blowing. When the fire reaches the top and the exhaust gases catch with a whoosh, start adding the ore and more charcoal alternating. Note a better furnace will have the interior taper opposite the height so that the charge is less likely to hang up while it is working it's way down---we would finesses this some while smoothing the interior. "The Mastery and Uses of Fire in Antiquity", Rehder, has a "foolproof" bloomery plans in an appendix using modern refractories. How do you plan to get your ore? In our early "clay" trials we would reserve about 1/3 of the clay for fixing cracks during the run. Using cob we now reservere about two handfulls of mix to cover "smokers", pieces of straw that go from the outside to the inside and so "smoke" when it's in use. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 10, 2008 Share Posted January 10, 2008 I'm not sure what the final plan will be but for now we'll probably mine the creeks for black sand using magnets. There are a few within reasonable distance cutting through heavily mineralized hills. There is also bog iron around though I don't know anyone who's collected any as such. One friend of mine, long since moved out of state, had a large lump he collected as a curiosity though he doesn't recall from which bog now, nearly 20 years after the fact. I'm not sure what construction tech we'll use, possibly fire brick possibly fire clay cob. Might as well use fire clay, it's reasonably cheap. We could dig our own clay at the coal mines but it's so full of coal flecks it's pretty unpredictable when fired. If you consider how much time and effort's involved in cleaning the clay it makes buying fire clay cheap. What I'm mainly interested in is the general nuts and bolts of it. I understand the specifics change with all the variables of different locations, materials, etc. etc. We also have an accomplished caster in the group who has experience with cupolas. In fact he and a local artist group will be hosting an iron pour just down the road from me next june. They're going to do three pours, one above the arctic circle, one in Fairbanks and one here in Wasilla. At least those are the plans, some locations may change as it develops but Wasilla is pretty well locked in. The point of that little digression is I'm leaving the refractory mix to Pat as he has the experience. He can also fine tune the cupola and fuel, ore, flux mix. Still, he hasn't done this himself so I'm sponging all the info available. Frosty Quote Link to comment Share on other sites More sharing options...
whitebear Posted January 10, 2008 Share Posted January 10, 2008 it seems to me that you could make one of those bloomeries and use it as a forge. it would get hott enough. like a adobe chiminia. Son Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 10, 2008 Share Posted January 10, 2008 The bloomery is sealed and the open end may be several feet away from the hot zone vertically. When you pull out the bloom it usually comes out from below the tuyere area and so not so good for a forge except for the residual heat when you first open it up! Dig a hole in the ground and stick the tyuere down in it and you would have a *better* forge than a bloomery would be. We have used ironsand "mined" that way to good effect; just be sure you don't get any from gold panners that have used Hg to extract gold from it! Bloomeries and cupolas are not that similiar in their running and heat balance---if you get cast iron you're doing it wrong in a bloomery! Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 10, 2008 Share Posted January 10, 2008 Sure though it wouldn't be the most efficient design. Some 15-18 years ago I made a forge on a similar pattern on a sand bar on the banks of the Resurrection River outside of Seward AK. The base of the forge was rocks and sand reinforced with salvaged rebar driven into the ground in a circle. The air blast was a damaged section of drill casing facing into the prevailing wind with sheet metal as a funnel. I started out with rebar sticking out of the top in a circle to hold the wood as it burned into charcoal but the heat was unendurable. I found a 15gl. grease barrel, cut the ends out of it and made openings on opposite sides at one end. I stood the grease barrel over the air grate with the doors at the bottom and filled it with wood. The barrel kept enough of the heat off me I was able to work the forge. I adjusted the air blast by opening or closing the sheet metal funnel. My anvil was an axel I fished out of the Resurrection River and buried flange up near the forge. The axel shaft was close to 3" dia. x around 3' long, the flange was about 12" in dia X 1 1/4" thick with 7/8" holes around it. The center of the flange was pretty flat. It made a really sweet anvil and I wish I'd packed it home with me. Why I didn't is another story though. So, anyway, a bloom furnace certainly could be used as a forge, just as a forge could be used as a bloom furnace. It's just that neither is intended for such. Frosty Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 10, 2008 Share Posted January 10, 2008 We have used ironsand "mined" that way to good effect; just be sure you don't get any from gold panners that have used Hg to extract gold from it! Bloomeries and cupolas are not that similiar in their running and heat balance---if you get cast iron you're doing it wrong in a bloomery! We'll avoid the gold mines or maybe I'll just test it and see what I find. If I were to start finding a decent amount of HG I'd have to consider mining and selling it. Heck the greenies would probably finance me even if it were a natural deposite. Yes, a bloomery and a cupola (per se) operate differently but structurally they're very similar. If we manage to get liquid iron I'm not going to complain! Maybe rethink the set up a little but no complaints. :cool: Frosty Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 10, 2008 Author Share Posted January 10, 2008 If one does this, where can I get the ore from?? Would black sand work as the ore? And is the bloomery only good for one firing?? I would LOVE to try this. Quote Link to comment Share on other sites More sharing options...
KevinD Posted January 10, 2008 Share Posted January 10, 2008 I copied the text from the "about this video" area and pasted it into Google language tools and came up with this.Added: October 07, 2007 The race is the oldest fire procedures for iron production. On the international symposia on the domain Heidbrink at Polle furnaces were rebuilt in a different design, and tested in practical operation. Quote Link to comment Share on other sites More sharing options...
Blacksmith Jim Posted January 10, 2008 Share Posted January 10, 2008 You could sift black sand with a magnet. It would give you iron filings. It just might take a while! Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 10, 2008 Author Share Posted January 10, 2008 What about the iron pellets that the RR drops onto the track from the rail cars? Is that ore?? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 11, 2008 Share Posted January 11, 2008 The taconite pellets are the worst ore we have ever used. You have to crush them as they are sized and cooked up for a full scale blast furnace. They also contain flux for the blast furnace so the runs we tried them on we ended up with "iron soup" and had to consolidate the bloom using tongs as a hammer would just splash! Note that the scale that comes off your iron work should be smeltable as it's essentially black sand + some alloys from the steel you are using---I'm slowly collecting some to try. Dragging a magnet along a streambed anywhere there is igneous or rocks can usually find blacksand to smelt---including places where it is only glacier moved igneous rocks. It is what the japanese traditionally used for making swords from after smelting in a tatara furnace. You can also buy magnetite as a polution control material---we did that once and the shipping cost more than the 400 pounds of "ore". There are other ores: hematite, goethite, bog iron, etc. Make sure you know what you are dealing with as it only takes a couple of percent to dye stuff rust red and if your ore is not richer in iron than your slag will be you won't get any iron to play with! Consolidating the bloom is a real workout and you have to start tapping lightly to avoid blowing the bloom apart---remember all the slag running out of that one in the video? It also should be done at a welding heat. gotta go Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 11, 2008 Author Share Posted January 11, 2008 Thanks Thomas. But will black sand work? I can get 100lb bags of true black sand for $10 a bag. The place is right around the corner from my dad's work. If it'll work, then I'll have my dad pick me up a couple of bags. Oh! if it does work, how much do you need and how far will it smelt down? Or will it stay roughly the same weight? And If I do this, is the "furnace" only good for one time? Or can I use the same "furnace" over and over?? thanks for the insight. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 11, 2008 Share Posted January 11, 2008 Take a magnet to it. If it sticks it'll work, if not it's probably something other than iron. If the black sand is blasting media it's probably slag or something similar. Not all black sand is iron and not all iron ore is a high enough concentration to work. Frosty Quote Link to comment Share on other sites More sharing options...
Vernon Posted January 11, 2008 Share Posted January 11, 2008 The stuff in our blast cabinet at work isn't true black sand, it's coal tar. After panning occasionally for years I never thought I'd find a USE for black sand! :D Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 11, 2008 Share Posted January 11, 2008 The black sand you get from gold panning or dragging a magnet through the creek or along a beach---in certain places, is magnetite one of the two oxides of iron and makes a great ore for smelting. The black sand you get in Hawii is mainly basalt and olivene and not good for smelting. The black "sand" (media) used for sandblasting is not good for smelting So as Frosty says use a magnet and test it *all* of it should be attracted by a magnet if it's magnetite! Quote Link to comment Share on other sites More sharing options...
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