Notes from Windward: #64

The Chair of Foundry Arts

      There is something fundamentally miraculous about molten steel. There are lots of tools which do lots of very useful things to steel and all the lesser metals such as brass and aluminum, but they all pale into insignificance when you take a crucible of molten steel, pour it into a mold and thereby create something new, something which can't be created any other way.

      Over the years I've been paid to do many different types of work; foundry work is the only work I've found that I'd pay to do.

      Before acquiring our land here in the mountains of southern Washington, we operated a trading company in the Nevada desert. We started out casting silver and pot metal for the tourist trade, and as we slowly gathered more pieces of equipment, we moved on to casting aluminum and brass, and eventually graduated to cast iron and steel.

      By the time we were ready to move north, we could cast up to two hundred pounds of steel at a time. Since then, our foundry equipment has been gathering dust, but we look to bringing it back on line in the near future. Only this time, we intend to use the power of the sun to fire our furnance.

      The heart of our foundry is a seventy kilowatt induction furnace which has the ability to heat thirty pounds of brass from cold ingot to pouring temperature in six minutes. To give you an idea of how fast that is, a propane furnace running full throtle needs at least fourty-five minutes to do the same thing.

      Induction melting is not just fast, it's very pure. Furnaces which operate by burning a fuel, and then directing the hot gas against the metal, change the nature of the metal they're melting. What you put in is not exactly what you get out, especially for a metal such as brass which is an alloy of copper and zinc. By the time the brass is heated to pouring temperature, a notable amount of zinc has already boiled off. If you're melting aluminum, the water content of the flame reacts with the molten metal, leaving a scum of aluminum oxide on the surface and substantial amounts of hydrogen gas dissolved in the molten metal.

      With induction, none of that happens. Brass melts so quickly that the zinc doesn't have time to evaporate. Aluminum melts without being exposed to the moisture that is produced by the combustion process. Alloys such as cast iron are melted without the introduction of elements such as sulfur which can affect the characteristics of the casting.

      No matter how many times I watch this proces work, it still seems miraculous to me. This particular miracle works by inducing an electrical field in the metal, and then letting it collapse. It's sort of like the way that the wire in a coat hanger gets hot as you bend it back and forth, only in this case the induction furnace flexes the molecules in the metal some two thousand times a second.

      Back in Nevada, we used a one hundred kilowatt diesel generator to power the furnance. The generator cranked out three phase electricity at four hundred and fourty volts. The furnance used water-cooled rectifers the size of hockey pucks to convert the incoming alternating current to direct current, and then used a series of massive capacitors to switch the power on and off two thousand times a second.

      This time we intend to use solar power to charge a bank of deep-cycle batteries which will function as a solid-state power supply for the furnace. With a solid-state power supply, we'll be able to cast any metal from aluminum to stainless steel, from brass to cast iron, without having to burn fossil fuels, without having to warm up and maintain a massive generator, and without having to pay a high surcharge to the power company.

      Right now, the furnance and most of the critical components are stored away awaiting the construction of a suitable building to house the furnace, the battery and the solar panels needed to charge the system. It's also waiting for someone to come along who shares a passion for molten metal and the wonderful things you can do with it. That person would become the Chair of Foundry Arts.

      What would the Chair do with this resource? The primary use would be to support our research and development work. There are many things that need specialty castings in order to produce useful equipment; there's only so much you can do with a welder.

      As for examples of products that the Chair could produce using this equipment, I'll offer two: anvils and statues.

      The countryside is littered with dead cars primarily because their scrap value is so low that it hardly pays to haul them a hundred miles to the scrap yard in Portland. In the eyes of a foundryman, a dead car is just begging to be melted down and reborn as a host of new products. The different parts of a car can be used to make all sorts of tools, and one of the tools most difficult to come by today is a heavy anvil. If you have any doubt about the demand for heavy anvils, just attend an auction where a two hundred pound anvil comes up for bid. You'll be impressed.

      Another option is the casting of brass statuary. Commercial foundries deal in production quantities of castings all of which are exactly alike. They melt vast quantities of metal to feed an endless line of moulds and there's just no time to focus on the detail needed in order to turn out artwork. In our case, the furnance doesn't need to stay hot; it can heat up in minutes. It doesn't need to melt large quantities of metal; just enough to do the job at hand.


For an example of another potential Chair, Click Here

Notes From Windward - Index - Vol. 64