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  • #16
    Steve: ifthe furnace you speak of is a ceramics Kiln it is useful. the cones are temp calibrated in small increments and (memory again) go to around 2300 F. I sneak some stuff into wifes- she says i will ruin it with oil- I claim high temps burn oil off. So far she still thinks I put only clean stuff in. The cones even in another furnace are a pretty good indicator of true temp (all ovens have SOME mis-distribution ofheat.


    • #17
      How did we get off onto this furnace subject? I thought we were talking about Chinese plants and bees or something. I got lost in the translation of melting glass with iron scraps. Will it make transparent steel?


      • #18

        If you do put it into production I would like to see it in picture.

        Size of coke, and busted up metal has to be a proper size to still allow airflow through the furnace.
        I bought a book by Chastain "iron melting cupola furnaces" look up
        It has plans and math for calculating furnace size and blowers.
        Jim Clary is the proprietor and also a machinist with a garage full of equipment. He is a damn nice guy. I have bought about 30 books from him now.

        Lots of luck friend, make full coverage apron, Welding gloves, arm covers, have a face shield, have shoe covers, work only on dry ground, watch out for fire, (you can't operate in a building) AND SEND ME PICTURES PLEASE.


        • #19
          You could phone your local Dental supply company and ask them about investment material etc or their advice with regard a suitable material which will not crack under high temeratures.I am not sure if you will get one hard enough for constant use but why not ask they might be helpful although this route could be expensive.They do supply many materials such as this for dental castings so it would not hurt to ask or alternatively ask at a company who manufacture furnaces if they would reccomend or sell you some of thir lining material.Alistair
          Please excuse my typing as I have a form of parkinsons disease


          • #20

            I bought a copy of Stewart Marshall's book on cupola furnaces. It's a pretty good all around book on furnace construction and operation. Though Wisconsin used to be a great foundry state, supplies aren't very easy to come by. I've found a local pottery supplier for clays, brick, etc. The closest place to buy coal is about three hours away. I don't know where to get coke in the midwest. Maybe Chicago? How is the situation in Mississippi?

            [This message has been edited by Dusty (edited 03-14-2003).]


            • #21
              Coke situation is okay we are about four hours from Birmingham,Al still lots of foundrys there coke goes for about.10cents a pound which works out to $10.00 a charge the single biggest obstacle we have had is locating the fireclay like looking for hens teeth.We finally found and old timer around here who told us that we were sitting right on top of some in our back yards told us to dig down about six feet and we would find a white/red clay with lots of feldspar in it he even told us how to mix and ram it in the furnace.
              I just need one more tool,just one!


              • #22
                My friend and I built a cupula years ago .
                I am not familiar with Chastains book, so don't know how much he says, but we had a heck ov a time getting started, UNTIL a real metalergist who worked for a Iron Foundry came to help..

                Here are some comments.
                You must preheat the air blast .our early cupula didn't use a wrap around air preheater, and we were "cooling" the melt.
                Our unit was 10 inches by 20 high.
                remember ..Preheat, Preheat, preheat, the air
                He said the air needs to be at 2700 +deg for proper reduction when it enters the cupula!

                We used "silver coke"...great stuff

                Do not use lime stone, or if you must, only a little. We charged with fist size chunks of broken flywheels from a local farm repair shop. great metal to use as it is clean!
                do not use radiators or window weights.
                limestone is for pig iron and plugs up the cupula .

                Keep several spare "Plugs' for closing up after a tap.

                Get some "Hot Shot".This is some metal pieces like pills and you put a couple in the crucible before a tap. When the hot iron hits the pills, an "exothermic" reaction takes place and the melt INCREASES in temp so you have more pour time.

                Vanadium additive helps machining a great deal..get some and add to the cruciable

                Safety is LAW
                When you see a fist size chunk of iron melt like butter in under 5 know you have heat! and Danger.

                Do not allow your feet to be anywhere spilled iron can each.
                We used a Kids sand box (but we had no kids )next to thee cupula and all pours were over the contained area.

                For you guys that have not been near a ciupla under blast, the heat burned off my hair when I was 5 feet away, so you must lower the blast when checking the Twiers

                Good Luck

                do they tell you about wedges ? to see how hard (chilled) the iron is ???
                Green Bay, WI


                • #23
                  Steve's design uses a wind ring around the waist of the furnace with one blower inlet feeding all four tuyeres,He also has a chapter on using down commers to boost air inlet temps and a chapter on oxygen inrichment to make cast steel(should be interesting). As for puoring we intend to run our moulds under the tap hole (after the first tap has been pulled off and dicarded) on a set of long roller tables,to keep crucible time to a minimum,I guess you could call it a pseudo production method.As for flux the most common method around here is to use ground clam shells as you can grind them up real fine and they are a lot softer than limestone.

                  [This message has been edited by wierdscience (edited 03-15-2003).]
                  I just need one more tool,just one!


                  • #24
                    Sounds like you got it, but make sure your molds are big enough. When that iron comes out, it isn't so easy to stop. thats why I said to have extra clay plugs.

                    Have Fun , and the 10 X 20 size was inside dims!
                    Green Bay, WI


                    • #25
                      How about a tilting cupola, I saw one once in a website that tilted. Would cutting off the blow and tilting it up cut the flow? or would it freeze? would you tilt it and leave the blow on? that would burn out any objects in the spout? cause it would have the least resistance :ie no coke several feet on it?
                      I want to build one here, I have a aluminum furnace waiting on more time to complete. I am using a 1/4 din temp controller with thermocouple and blower control. I hope to make adequate dies here for casting motorcycle parts. I am torn between charcoal and propane as a heat source.
                      ALL the books say to start with aluminum to learn all the saftey tips. It melts out about 1200 if I remember correctly, as opposed to the 3800 I kinda remember on steel-iron.


                      • #26
                        Little hick school i went to had a couse in foundry where we melted cast, rammed molds etc. I THINK they advised having a place to pour any excess. I say it would be good advice for a beginner- I had trouble even as a young man getting my plug in a hot hole.