An interesting article, safety considerations aside.  I followed the link over to United Environment Architecture.  While they claim this is an open process, no plans are given for the blast furnace.  They do state, however, that it's a charcoal based fire, so I think we can assume that they use an electric blower to crank up heat from briquettes.  Throw an enclosure around it to contain the heat and focus it on a crucible and you got yourself a nice little blast furnace.  Something like this would be a nice pre-cursor to the GVCS Induction Furnace.

- Mark

Hi Matt & Mark,

Thank you for your interest in our work! Matt, you're absolutely right: Gingery provided an excellent starting point for our blast furnace work. We read "Charcoal Foundry (Build Your Own Metal Working Shop from Scrap Book 1)" http://www.amazon.com/Charcoal-Foundry-Build-Metal-Working/dp/1878087002, and looked at fair amount of youtube footage before coming up with a simple blast furnace design. Mark, I've been putting process photos and some how-to info (and a nod to Gingery) on our facebook page: http://www.facebook.com/uearch.

Some info on the blast furnace:
- the refractory material for insulating the furnace can be made from a mix of silica sand (2 parts) and fireclay (also called mortar clay at some building suppliers - 1 part by weight), with a minimum water added to hold the mixture together (about ~10% by weight). This is packed into a container (a steel garbage can in our case) against a removable  cardboard form, and then dried and vitrified by running a fire in the furnace.
- air flow was provided by running a hose from the outflow of a shopvac, with a homemade valve fitted in the line for flow control. An air-compressor also works but was less effective in tests. We are working out a homemade blower for more silent operation. Gingery advocates using a simple blow-drier.
- Crucible was home-made from a pressure tank that was ground and welded for the purpose
- We tried using hardwood charcoal, but found that barbecue briquets work much better and create far less sparks under high air-flow. The self-lighting variety are an efficient way of getting the furnace going.
- About safety: We've been criticized for our 'safety practices' and attire on occasion. Having a fair amount of personal experience with metal-work, I find this amusing and often misplaced. There are attendant risks with working with molten metal, but they are easily anticipated. Eye-protection when pulling the crucible or loading the furnace is a must. Ventilation is key for long-term safety. While heat and fire show up as dramatic on film (and provoke the most vocal reactions!), the greatest risk comes from lack of air circulation/exchange. Aluminum puts off toxic fumes when melting, and burning charcoal of course produces carbon monoxide. We do all of our work outdoors, and do not recommend a charcoal setup for indoor use. Vented gas-fired setups can be purchased for indoor work.
- Photos of all of the above can be found on the aforementioned facebook page.

We are far from experts on the subject, but we're always happy to share what we've learned and discovered. I'd be happy to answer any questions or provide more detailed information - please don't hesitate to ask. Good luck with your own furnace project!

Best,
Tada

Haha...I make it a personal policy to avoid doing things that could injure or kill me while simultaneously generating no sympathy. Cooking up a batch of molten metal without a shirt is one of those things. If someone got hurt, I'd probably chuckle a little, so I'd expect the same if I was doing it and got hurt :D

Hello Mark

mjn wrote

;)