History of Electric Induction Heating

Electric History

By James Farol Metcalf

James D. Nisbet, Allvac

James D. Nisbet graduated from Clemson College in 1937 and was employed at General Electric where he worked at Fort Wayne, Indiana as a metallurgist for gas turbine alloys until the end of WWII. After the war he was assigned as research engineer in Schenectady where he worked on alloys for jet engines.

The metal alloy used in jet engines during the early period was a modification of an alloy named vitallium. Austenal (later to join Howmet) developed this cobalt-based alloy for the dental industry because it was easy to cast and had very good resistance to saliva corrosion.

In 1953 he was assigned the task of building a pilot plant for melting superalloys in vacuum. (This was one year after Jack Huntington at Special Metals has shown the remarkable improvement in Waspaloy by remelting scrap in vacuum.)

Nisbet needed a control panel for his furnace and Ajax Electrothermic was no longer interested in this equipment. A new company, Inductotherm, had just been formed that would supply the equipment. From "The Fire Within" copyrighted in 1995: "It's always darkest before the dawn, and it was only a few days later that the darkness we were suffering was broken with a beam of light that would mark the turning point for our floundering company. Inductotherm received an order for a 100 kW vacuum-furnace control panel. It was a much smaller project than the Sorenson job would have been, but at $5,350, it was a substantial contract nonetheless, worth more than our total sales since we'd founded the company. No less significant than the size of the job was the stature of the customer--General Electric. It was for the GE Research Lab, to power a vacuum-melting project headed by a young research engineer, Jim Nisbet. Little did we guess then what role he would play in our future, or us in his."

In late 1954 Nisbet accepted the position as the Director of Research and Development for Cyclops in Pittsburgh. During his employment at this specialty steel company he oversaw the construction of a one-ton vacuum melting facility.

In January 1957 Nisbet decided to open a business to melt metal in vacuum that he planned to sell to the growing market for jet engines. He selected his hometown area in Monroe, North Carolina for a new company he would name Allvac. He convinced MIT Professor Nick Grant and Henry Rowan to serve on his board. Rowan invested $10,000 in this new company when he received an order for the induction power supply and a five hundred-pound furnace. Nisbet started off with $325,000 and in less than two years would be teetering on bankruptcy.

Rowan flew down for the first directors meeting in August 1957 to pick up his order and swap his Ercoupe for a Bellanca.

In late 1957 I heard about the new operation in North Carolina while working at Cannon Muskegon in Muskegon, Michigan. I had been working in the field of superalloys since early 1955 with my first job being a melter at General Motors Research. After GM my next job was at the Carballoy division operating a vacuum melting furnace. My next job was as metallurgist at Waimet Alloys. (Later to merge with Howmet.)

The paycheck at Allvac would be much less than I was receiving at Cannon Muskegon but Nisbet gave me a stock option and a chance to be Vice President. Allvac agreed to pay for the moving company and were pleased that it was not expensive. When the van arrived in Muskegon there was a heavy wet snow so the official weight of the van was much less when the snow melted during the trip to Monroe.

In January of 1958 the equipment was still being installed for the rolling operation. The rolling mill was made in 1890 and had been used for final rolling of sheet metal. It had no chance to work on superalloys. A single crane mounted on a monorail serviced the whole shop including tilting the furnace in the vacuum chamber and the charging device. The whole facility was built as cheap as it could be to accomplish Nisbet's dream.

My first task was to sinter the zircon oxide refractory in the 500-pound furnace using a graphite cylinder. I had done this many times before for previous employers but it was my first time to start up an Inductotherm induction system. The 175 kW horizontal Westinghouse motor generator looked a little more modern than the General Electric units I had started before. The TOCCO generator I had started before was vertical and was better looking.

The handle for the motor starter looked the same so I pulled her down to start up position to count off the twenty seconds required at low voltage to get the system up to speed. I did not need to count the seconds because the 1000 cycle hum told me she was ready for full voltage. The Inductotherm control panel was much easier than the panels of Ajax and TOCCO so it was easy to look through the sight glass to know when the correct temperature was achieved.

It was clear right away that Nisbet could not or would not be the engineer or the metallurgist for his new operation. He was a businessman pure and simple. For this moment in time I was just what he needed because the young farm boys, while eager, needed to be trained to melt alloys in a vacuum melting furnace. There were only a few orders to be filled and no money to use on building inventory so the opportunity to train was limited.

Allvac's chemical laboratory consisted of a device to measure carbon and sulfur levels. All other elements were measured with a mass spectrometer by a firm in Cleveland. Nisbet let me hire Gary Mills to be my assistant to run the lab and do the drawings. Gary was the only person from the startup group to retire in Monroe.

Nisbet's brother was in charge of sales and found some orders but these required a 2000-pound furnace. In the spring of 1958 Rowan attended a board meeting at Allvac. The year ending April 30,1958 had been very good for Inductotherm and Rowan with sales of $1,396,000. These sales included Allvac and Beryllium Corporation and a vacuum melting system to National Research Corporation. At his time Rowan's order book was empty due to the shift in military spending to counter the Soviet control of space with their "sputnik". It was also a time of economic recession. He offered to build us a 2000-pound furnace on a toll basis at two-cents a pound melted. During my time at Allvac he earned $4 on the lease.

Nick Grant's students at MIT completed a statistical analysis of several hundred lots of metal looking at tramp elements that might be causing the large difference of stress properties. It was clear that melts that contained a few parts per million of boron were the good ones. This finding was confirmed at Special Metals in a series of melts. Grant suggested that magnesium oxide linings were producing better product. He also noted that these hard to forge metals could be easily forged if cooled in a copper mold using a welding method to melt the metal as it cooled in the mold.

To sinter the new lining we used scrap steel from around the shop. The melt was in the fourth hour with no sign that it was melting. I called Rowan in Delanco to see if we could get a little more power from the system. He told me to bend the needles (in other words to operate above the red line). I was concerned that the equipment would be damaged. He told me, "A man who never breaks his shoestrings is spending too much money on shoestrings." This was a lesson never to be forgotten.

Soon the metal bridge above the molten metal broke and we were ready to pour. The mold was a piece of heavy wall steel pipe sitting on a graphite plate. Just as we were finishing pouring the graphite split and a ton of hot metal spilled to the bottom of the vacuum chamber. The liquid steel melted a hole in the bottom of the chamber and most of it escaped to the outside under the chamber. Someone found a homeless gentleman at a gasoline station nearby. He cut and welded for almost 30 hours to fix the hole. There was no damage to the melting furnace.

We proceeded to the production melt and things went fine until the metal was liquid. The chamber was not water cooled and the larger melt was burning the paint on the chamber. We used a garden hose to keep it cool until the melt was completed. To fix that problem we welded some angle iron along the side to catch water that was fed from a garden hose with holes in it. I returned to visit Allvac some years later and the larger chamber they had installed still used this type of water cooling.

Nisbet obtained the rights to make radio speaker magnets from General Electric. The blind led the blind as we attempted to become good magnet suppliers. Sugar was used to hold the sand together for casting the little magnet. We almost destroyed the plant when the furnace exploded as the result of the sugar vaporizing into a gas in the vacuum chamber. When the operator let in the air to release the vacuum, the ten-foot door was thrown about two hundred feet down the shop.

Mills introduced me to his high school friend, Bob Williams, who had decided not to return to college. His brother was working for Allvac also recommended him so I hired him on the spot to help with the magnet business. When Nisbet learned that I had overstepped my authority by hiring an employee he told me that it was a firm rule against family members working for the company he paid Bob for the day and let him go. I visited Allvac on April 14, 2004 to find Williams sitting in the chair of the president.

Nisbet fired me when my son, Kenneth, was only two months old after I failed in the mission impossible speaker magnet business. Rowan suggested a separate operation with me running it would be the only way to make this business succeed. He did not have the money to continue my relatively high salary. An exchange of letters between Rowan and Metcalf in 1988 adds information on this moment.

The year 1958 was the end of my direct training in superalloy technology. These work experiences taught me the nuts and bolts of that industry and a little metallurgy. The main contribution that I made to the future of vacuum melting furnaces was the use of aluminum screen band strapped across the bottom of an open pipe. The screen held raw materials or scrap. When this pipe was lowered into the heated furnace the aluminum became hot and weak and therefore was torn by the weight above it. This method was improved a little over time as metal producers found better ways.

James D. Nisbet went on to bigger and better things including Vasco and Teledyne before again setting out alone in 1976 as Capital Technologies Inc. managing assets for individuals and businesses. It was here he wrote and published his copyrighted book, "The Entrepreneur" in 1976.

His book has a few events of the early days out of sequence and he never mentioned my name. On page 64 he makes a very misleading statement: Firth Sterling finally copied our furnaces at their McKeesport plant. Joe Lona and I completed this furnace in late 1961 while working for Ajax in Trenton, New Jersey. The only thing I took away from Allvac was the idea to build cheap vacuum induction furnaces.

His book also noted that Carpenter Steel installed their facility. This was an improved version of the Firth Sterling at Joe Lona and I completed in 1963.

In a search for additional information in March 2004 I found that Allvac had become a part of the Allegheny group. I also found that Nisbet published another book in 1998 with the title "Wheels UP".