Marshall Machine

Hi, thanks for the invitation to join the forum.  I don't do much blacksmithing but I do have two forges and my old family anvil from England.  Mostly I cast bronze and gray iron, and also have a machine shop so that I can finish the castings.  I melt with cupola furnaces which are basically very small blast furnaces and use coal or coke.  Coke burns a bit cleaner when you first light off, but either one works OK.  And with the right blast pressure at the tuyere I get almost 3000 F.  My smallest furnace is only 7 inch bore, large enough to get my hand inside to chip it out after a pour.  I blow it with a shop vac and use fuel about the same size as blacksmith coke.  These furnaces are very fast since they are top loading and continuous melters.  In the 7 inch, I have hot metal at the tap hole in less than 8 minutes from putting on the blast, then another ladle full every 4 minutes.  So the furnace is many times faster than a normal modern gas or electric crucible kiln.  Also, crucibles are expensive!  So a cupola does not need one.  You simply tap the furnace into a steel ladle that is lined with the same refractory as the furnace, or else use some of the new ceramic fibre 'dipping' ladles that are sold as sampling ladles for bigger foundries.  Anyway, I wrote a book on building different sizes of these small cupolas and sell it along with a photo CD on my website.  Here is a link below if any of you are interested.  These furnaces are cheap to build, basically just the cost of the refractory lining.  They work great for most of the bronzes as well as iron.  I even melt steel scrap so that I get a stronger cast iron (can't pour a steel casting however - the steel turns into iron from picking up carbon from the fuel).

http://www.rockisland.com/~marshall

cheers, Stewart Marshall
Lopez Island, WA
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Hank Rearden
Hi Stewart,

First I want to say thank you for adding to the forum on the subject of foundry. I didn't think it was that feasible to do it at home. I live in Central PA. and we have a number of early American iron furnaces still standing. Most have been turn into parks. I also live near the old Bethlehem Steel Mill in Steelton PA.

We had a field trip to the mill for Cumberland Valley High School metal shop. It was during and actual operating shift at the mill. We watched rail road ribbon rail and rebar from melting scrap steel in the furnace to taking the samples for testing. What a day. We actually walked between the roller mills as they rolled hundreds of feet of red hot steel. It zipped by us at high rates of speed like it was giant untamed snakes. You defiantly paid attentions to what was going on around you for fear it would jump off the rollers and get you.

Anyway, I watched the PBS special "Forge" Crafts in America last week and the second artist featured made a bronze casting of a skull. What interested me was how they made the mold to cast the skull. I used a 2 piece sand mold in high school to pour aluminum castings. It was simple enough.

I was wondering what type of molds you use to cast bronze? Are there any resources you could share on mold making to pour castings?

I making a shop now. Foundry is something I would like to eventual incorporate into it as well.

Thanks,
Victor
 
code[Maglio.gif]  Keep the fires burning hot!
2020 ABANA Conference in Sarasota New York. June 3rd. through June 6th. Plan now!
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Metalmelt
I got a copy of Stewart's book "Building Small Cupola Furnaces" and the cd. It's a great book for the small iron caster. I'm still in process, gathering materials and making plans on paper. The build will have to wait until we figure out where we want to live.[confused]
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Anubhav Gupta
Hey!
Thank you for adding me to this forum. I have read a lot of posts on this threat and forum also and these are very useful. I have been studying forging since a very long time and I am able to gather a lot knowledge about forging, foundry melting with coal and coke and a lot more. There are various companies that are providing the forge and flange manufacturing. But there is a company that is doing this work in the top notch quality and delivering excellency in the product. I am using the services offered by CHWForge since a very long time. I would definitely recommend everyone to go for this company.  
Just follow the link: http://www.chwforge.com 
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Hank Rearden
CHWFORGE has a nice website. It's good to see the industrial side of this craft as well. Thanks
code[Maglio.gif]  Keep the fires burning hot!
2020 ABANA Conference in Sarasota New York. June 3rd. through June 6th. Plan now!
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