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I Forge Iron

Joe111

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  1. Been doing this since I was 15. Im 72 now. I own foundries and mills on 3 continents. But you are right. I know nothing. :D If you want certs, look them up yourself. Anyone with a simple knowledge of chemistry will realize that metal oxides in a reducing carbon laden atsmophere is a really bad idea. Look it up yourself in Ijera or jstor or springerlink . You will probably even find some of my work there. :D I see with 10,000+ posts, you have plenty of time for hands on work. Lots of experience. That's years on the internet by the way. I come here to give for free my experience and all I get is bs from people who are experts in their own dreams. Sad...Too bad.
  2. The point was long term expense. Hard refractory vs insulating refractory. Price was for castable refractories. He will have many heat cool cycles. That is the nature of founding. The hard refractory will last him a decade if he dosent break it. The insulating castable will last only a few cycles before it spalls and need to be repaired. Insulating refractories by their nature are porous. this allows gasses to enter and attack the oxides and reduce them to their base metals. A fuel fired furnace needs to be restrictive in gas flow. The heat needs residence time within the furnace for it to be efficient. Most crucible furnaces are designed with a exhaust port that will flow 50% of the required gasses at atsmopheric pressure. Some flow even less. That plus the permeable nature on the insulation leads to gas flow thru the insulation. This leads to deterioration of the lining and low insulatining efficiency. The ceramic fiber is a bad choice all around for this application. Don't get me wrong, I use it and like it a lot. But it has neither the required resistance to reduction nor the mechanical strength to survive in a fuel fired crucible furnace as a hot face refractory for much time. You can coat it all you like but you wont make it airtight. The surface wont decay but the interior will. Just ask yourself how many times you hit the lining with tongs? it will rip the fiber or crack the coating. Both will cost you money. Another aspect to the hard refractory is its nature to store heat and release it in the needed range. Instead of the heat going out the flue, it is radiated directly into the crucible. resulting in a large savings in energy.
  3. The kaowoll wont last long. Insulated refractories will be in the $500-600 range for that size furnace or more. Also furnace atsmophere is very important. Most lightweight refractories don't like reducing atsmopheres.
  4. I generally use silica sand (quartz) and Lincoln fire clay.Both can be found at most ceramic stores. The silica sand can be found at aquarium supply stores too.
  5. Pounding ore into steel is much different than melting it for casting. Don't confuse the two. About the only way you can do it on a small scale it melting it in a crucible (preferably zirconia) then refine it with an oxygen lance. You can melt steel scrap either with a induction furnace.(Which you probably don't have access to) or in a oil or gas furnace. You need a crucible with a cover. Wear lots of protective gear and pay your insurance before you start. Preheat the crucible Fill the bottom 1/4 of the crucible with charcoal then add the steel to it is 3/4 full. Then fill the rest with charcoal and put it in an already hot (yellow) furnace. You want as neutral of a flame as possible with the furnace so you can see the orange flame from the CO burning in the air as it excapes the furnace. When the orange flame stops the steel is melted or the furnace wasent hot enough. You need bright yellow or higher heat for this. Shut off the furnace and open the furnace and crucible. Stick the lance (carbon) into the crucible with the o2 flowing and the molten steel will start to boil. It may spray everywhere) until the boiling subsides. The more impure the steel the longer it will boil. Pull it out and pour your ingot. This will be a sort of mild steel. results will vary. Now, there are many types of steel. Most require additions of ferro inoculants which you probably cannot get. But you can make yourself with much more investment and time. You will also need a lab of some sort. Expences varies with education and experience. If you have iron ore, start with a cupola, pour it into a crucible and lance it. It will however boil much more rapidly. Ive done this many times. I don't recommend it to anyone who isn't a hardcore metal melter. It is dangerous, messy and very pyrotectnic. And did I say dangerous? However. not many people can say they can do this either. If you really are interested in this read everything you can about the subject before you start and have a partner to help. You need help.
  6. That is not a cupola. It is a bloomery. Just not your version of one. If you want to make a primitive one out of primitive materials, then you need time. lots of time. You will need to build a clay shell and fire it. Then take days to run your campaign. There is a reason it is called a campaign. It takes lots of time. If you are using clay as a liner, it will need to be thick 4-6 inches at least. and before you add your ore, you need to bring the entire thing up to temperature. A cupola burns fast and hot. A bloomery burns slow and hot. It is deficient in both air and fuel. This is the condition that produces the mallable iron that you want. Otherwise you will only get a lump of hard, high carbon white iron that is useless for anything. Melty, melty is just what you want. But you want the conditions right to reduce the liquid iron to a solid form in the furnace at the correct temperature.
  7. Ive made many hundreds of tons of malable iron and much, much more cast iron using simple furnaces such as this. The only real difference in the processes is the amount of o2 you add. Too much you get cast iron and just a little you get malable iron. Either way you still need the flux. This photo is of a malable iron heat. The iron drops out the trap door in the bottom after the heat has cooled. It is pretty much layered between solidified flux and iron. There is some pieces of slag and carbon in in but you are absolutly sure it is iron. No guess work there. It is a half to all day affair for one heat depending on the quality of the ore you use.
  8. Not all but pretty much most of it will melt at quite low temperatures. The red refractory clay isnt very easy to come by.
  9. Real wrought iron is not easy to find these days. About the melt. You will never get it hot enough to melt the iron in that pot. You need a yellow to white hot heat and where is your flux? Limestone works well. Red riverbank clay works well. You will never get wrought iron. Only a form of semi steel depending on carbon content. Wrought iron comes from all the impurities being removed from the pure iron then the melt will melt no more and become like dough and can be rolled up. If you are serious on melting it. Grind up your ore and add some red clay and powdered charcoal. Roll it into balls about 1/2" in diameter. Let it dry well. Put the balls into a crucible and put a lid on it. Fill up all the voids in the cruicible with powdered charcoal .Place it in a already hot furnace and heat it as fast as you can. Keep looking at the crucible and when you stop seeing gasses come out between the crucible and lid turn the fire off and let it cool. If you got it hot enough you will find all the iron at the bottom covered by a hard layer of hardened slag.
  10. You can melt pretty much any metal with wood.Used to melt a ton of cast iron ingots per 8 hour day in this wood fired curcible furnace. Every part of it was made by hand from materials dug from the ground such as china clay and silica sand. We obtained temperatures in excess of 2900F.
  11. I worked in a metal spinning shop for 10 years making blower parts, nose cones and even some millitary stuff. Its not hard at all.
  12. Magnesium is not for the beginner. You will more than likely burn down the building. Everything has to be different from closed crucibles in reducing atsmopheres to non silica based furnace linings. Generally it is cast in metal or olivine sand molds. No silica or plaster here. Then alloying it is expensive and hardeners are difficult to get also.
  13. Depends on how much material you want to melt. If you are just doing aluminum, Which is probably all you can do in a forge. Then weld a cap to a piece of pipe and some lifting lugs and you are ready to go. Im sure you arent making millspec items so the small amount of iron absorbtion wont be a problem. Or if you want to buy one there are many options such as here: http://backyardmetalcasting.com/. The problem is that no only do you need to buy the crucible but the lifting tongs and pouring shank also.
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