MattBower Posted December 29, 2010 Share Posted December 29, 2010 My temptation is to do true reverbatory furnace, but we might just use your suggestion with a ribbon burner in the roof. Larry has a large ribbon burner and I have some large blowers. Funny, often these projects get more complicated is they reach reality, but this seems simpler now than it ever did. Might cast a basin using a castable refractory. Same with the roof. Kind of a turtle shell construction. Fifty pounds of scale, fifty-sixty pounds of cast iron and we'll be ready to go. If it's not a reverb, I guess it might not be a true "puddling" furnace anymore. But who cares, as long as it works? I think the reverb construction was driven by the need to keep the nasty stuff in coal (sulfur, mainly) away from the molten metal. If you're not using coal, reverb may be unnecessarily complicated. I guess my suggestion is closer to a propane powered finery forge, really. By the way, I did find a few reference in old books to natural gas powered puddling furnaces. Didn't find any construction details, but supposedly they worked really well. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted December 29, 2010 Share Posted December 29, 2010 It would still be a puddling furnace wouldn't it? I mean there will (hopefully) be a "puddle" of iron in it after all. What would you call it? A "piddling furnace"? Quote Link to comment Share on other sites More sharing options...
MattBower Posted December 29, 2010 Share Posted December 29, 2010 It would still be a puddling furnace wouldn't it? I mean there will (hopefully) be a "puddle" of iron in it after all. What would you call it? A "piddling furnace"? The thing is that there seem to have been a bunch of different setups for decarburizing pig iron, and they all had different names (sometimes more than one) in the old books. But it all boils down to taking pig, melting it, and oxidizing it with some slag until it starts to go solid. Quote Link to comment Share on other sites More sharing options...
fciron Posted December 29, 2010 Share Posted December 29, 2010 It would still be a puddling furnace wouldn't it? I mean there will (hopefully) be a "puddle" of iron in it after all. What would you call it? A "piddling furnace"? 99 % of the furnaces discussed here are piddling furnaces. First you piddle with the furnace, then you can piddle with some hot steel. :D Quote Link to comment Share on other sites More sharing options...
basher Posted January 1, 2011 Share Posted January 1, 2011 I think this is a very interesting proposition . my initial response was why take a good modern material like mild steel and turn it into crappy wrought iron ? but looking at it from the pig iron end I don't really think its all that hard an undertaking using modern gas burners . I shall have a little read through some books I have .and re post . some initial thoughts ... I wonder if smelting slag would be a good enough slag to oxidise cast iron. does the stirring process bring more molten steel into contact with oxidising air ? without it you would be looking at a slag covered cast iron mass . I seem to remember reading about granite hearths being used and these being a consumable ?(I'll check this) would adding processed ore (hematite or magnetite) to molten cast iron help with the oxidising process or does iron oxide need gaseous carbon monoxide to reduce ? (I am uncertain as to which has a greater afinity to carbon iron or iron oxide ?) my other main query about this process would be how much wrought you can remove from a puddle of cast iron before the process stops working ? I am imagining the process needs a large liquid metal content to provide an interactive surface for slag and air interaction as well as general mixing . so do you need a 100lb puddle to get 20lb wrought ? add another 20lb pull some more wrought etc . this is very interesting . Quote Link to comment Share on other sites More sharing options...
MattBower Posted January 1, 2011 Share Posted January 1, 2011 Hi Owen. Based on the reading I've done, I think I can answer a couple of your questions. does the stirring process bring more molten steel into contact with oxidising air ? Absolutely, yes. would adding processed ore (hematite or magnetite) to molten cast iron help with the oxidising process or does iron oxide need gaseous carbon monoxide to reduce ? Yes. (The fact that oxygen will leave iron in order to combine with available carbon is the reason bloomeries work. ) The old timers called this "wet puddling" or "pig boiling." Quote Link to comment Share on other sites More sharing options...
basher Posted January 1, 2011 Share Posted January 1, 2011 I can see why it would be called" pig boiling" as iron oxide and slag certainly spit and boil (in a direct reduction crucible setting any way) . I wonder what the economies of scale of this process are....... as in how small can you go and still get a result ? I have a forge in in april and think this would be a great project .... as far as available carbon is concerned......bloomeries have a large quantity of available carbon as Co and I wonder how available C in cast iron is ? Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted January 1, 2011 Share Posted January 1, 2011 I think most of the decarburizing is done by the slag made up of mostly iron oxide scale. The oxygen in the iron oxide combines with the carbon in the cast iron. This would free iron from both. Not sure why someone thought this fit better under "Casting". Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted January 1, 2011 Share Posted January 1, 2011 as far as available carbon is concerned......bloomeries have a large quantity of available carbon as Co and I wonder how available C in cast iron is ? Not sure what you're wondering here. The carbon in cast iron is available enough that the process results in very low carbon wrought iron. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted January 2, 2011 Share Posted January 2, 2011 The practice with white cast iron was "dry puddling", that is without the iron oxide slag. With gray cast iron it was necessary to use iron oxide to remove the carbon, hence "wet puddling" or "pig boiling". Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted January 2, 2011 Share Posted January 2, 2011 Not sure why someone thought this fit better under "Casting". If this thread does not belong under "Foundry and Casting" where do your feel it should go, back in general smithing where it was started? :D Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted January 2, 2011 Share Posted January 2, 2011 I wouldn't move it "TO" anywhere. Other than the fact that it is neither founding or casting. I can understand moving something when it obviously belongs somewhere else. "Founding and casting" just doesn't fit. "Everything else" fit as well as anything. Not a big deal at any rate, just musing. Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted January 6, 2011 Share Posted January 6, 2011 "Not sure why someone thought this fit better under "Casting"?".............I guess cause it involves molten metal and "are you on drugs?" They both seem to go together you know. All very interesting :D Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted January 6, 2011 Share Posted January 6, 2011 Well, then I suggest the forum be named "Melting & Smelting"! Quote Link to comment Share on other sites More sharing options...
MattBower Posted January 6, 2011 Share Posted January 6, 2011 Maybe we should have one of those. Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted January 6, 2011 Share Posted January 6, 2011 "Melting & Smelting"!..........OH! yeah that sounds much better, I like that! :P Quote Link to comment Share on other sites More sharing options...
Stefflus Posted March 6, 2013 Share Posted March 6, 2013 How did this turn out? I'm reading a book called "Classical Ironsmithing" (Klassiskt Järnsmide), a Swedish book by Karl-Gunnar Norèn and Lars Enander. And it describes -among other things- Fineries as done by the Puddle-, German- and Walloon method. This caught my interest, and I rumaged thru some other books and internet articles hoping to find better illustrations. But no such luck. The Walloon method (which I think is what produced "Swedish Iron") is described in the book as sticking a 1000-2000lb beam of stock into the hearth, heating the end, and going at it with spikes until a 40lb piece was worked enough to be sent to the trip hammer for consolidation. But there is no real helpful illustrations of this, or of the other methods, so I'm left guessing how this really happened and how the hearth looked as to position of stock and tuyeres. Do you have some? Quote Link to comment Share on other sites More sharing options...
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