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Radio as it Used to Be by Walter H. Smartt, M.D.
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Few radio hobbyists will recall the American Lava Corporation, which was on the cutting edge of electronics development over most of the 2Oth century. Its first logo was "ALCO" (for American Lava Corp.) and later "AlSiMag" (for aluminum, silicon and magnesium; the principal elements of their products). The firm was the largest and finest producer of ceramic insulation worldwide. My family was deeply involved early on, and my dad was Secretary. I want to tell the AlSiMag story from a hobbyist's standpoint while I can still remember details. Unlike Isolantite, which was a French company, ALCO did not place its name or logo on any electronic product. There was no retail business; they made ceramic products for other corporations.
The most popular of the tips was the "Cabot," which was used in home lighting. With this tip, the flame burned red and in a fan shape. The auto headlights of the time also used a gas flame, but the fan shape was useless for this purpose. For headlight use, ALCO developed what was called the "Lava Tip." This burner was y-shaped with holes on the inside of each end of the tip so gas could exit. Additional holes were provided to admit and mix ambient air. The flames were bluish and, where they crossed, very intense and concentrated. This made it possible to collimate and magnify the beam as required in spotlights. The first manager hired by the Germans was P.J. Kreusi of Swiss descent, the son of Edison's assistant in the development of electric lighting, telegraphic equipment, the phonograph, and other inventions. Kreusi selected Chattanooga as a location because he wanted to marry Myra Smartt, a Chattanooga girl, and because soapstone could be obtained from nearby Hewitt, North Carolina. In 1902 operation began in Market Square near the original Coca-Cola bottling plant. During World War I the company, being German, was seized by the U.S. Government. However Kruesi allowed to stay on as operator. After the war he bought the plant, later selling 51% of the stock to his brother John and the rest to other employees. After John died intestate, P.J. had to return as president to look after his family's holdings.
Everything had to be made oversize because the sintering process, carried out in periodic kilns, made items shrink. The kilns were fired by kerosene that cost 8 cents per gallon. If something came out large, it was run back through the kiln at a higher temperature; smalls were discarded. What couldn't be shipped to customers was my treasure trove. The myriad of shapes were better than Lincoln Logs or Erector Sets as childhood playthings, and they were free. Sadly, I have saved fewer than a dozen pieces! As the business became more technical, the shrinkage in firing necessitated the use of oversized drills and taps which had to be made in-house. Firing was at around 1800 degrees Fahrenheit. The temperature was controlled by watching pyrometer cones through a peephole. These would sag and collapse at the proper temperature. The same method of temperature control was used in the firing of pottery and porcelain. The "Lava" in the company name referred to the extreme heat used in the manufacturing process--similar to that of the molten rock produced by volcanoes. This caused much confusion because many people thought the company made "Lava" soap. I remember conducting "industrial espionage" on Sunday afternoon rides with my father. A competitor, D. M. Steward (still in existence) was close by, and Dad would drive past to see how many lights were on in the building and to study their junk heap for a glimpse of what they were making. He was always trying to get a jump on the competition. The company's first pressed-talc (ground-up soapstone) product was a holder, about the size of a pack of cigarettes, for a glass-vial mercury switch. It was made on a hand-operated porcelain press looking much like Ben Franklin's printing press. Adding a pressing department required new methods, and machinery like grinders, sifters and a mixer called a "melanger." Borrowed from the chocolate industry, the mixer crushed and mixed dampened talc in a granite dish about eight feet in diameter rotating under two giant granite rollers.
Products so made were damp and had to be dried before firing. When finished, the piece was hard enough to cut glass. This process finally could produce a uniform product held to very close tolerances. Customers flocked in, knowing their orders could be filled with absolute uniformity. Old-fashioned ingenuity was supplied by a natural-born genius, one Blake Hullender. Blake was capable of de-bugging anything coming from the engineers and making it work clear through to the shipping department. Tube bases, tube sockets and condenser discs were made by the millions! The most ticklish product to be developed was a result of a need for radio-tube manufacturers to insulate filaments in the new AC-heated tubes from their surrounding cathodes. Early AC-heated tubes like the Sonora RA-l used 14-volt toy-train transformers to heat a filament wound around a threaded soapstone insulator about half the size of a pencil. This took forever to heat up, due to the mass of the insulator. What seemed to be needed was an insulator the size of a pencil lead, or smaller, which had one or more longitudinal holes through which the filament wire could be pulled. GE developed a way to do this and, through the Edison-Kruesi connection, rights to the process were given to ALCO to perfect and mass produce. The process involved making small batches of mostly magnesium oxide in ball mills, tumbling for a very long time to grind and mix the ingredients to a very small particle size. (This process was locally called "MGO" for its principal ingredient.) The prepared powder was moistened and loaded into an ordinary Alemite grease gun. A die at the outlet formed a spaghetti-like strand with a concentric hole. As the operator cranked the grease gun with one hand, he used the other to move a grooved wooden plate to accept the extruded product. Quite a feat of coordination! The completed strands were dried, cut to length, then fired in an electric muffle furnace the size of a carton of cigarettes. The furnace was kept supplied with 100% hydrogen to keep the heating elements, made of molybdenum wire, from burning up. This was a lucrative activity until manufacturers found that all they had to do was to dip or spray their filaments with an insulating coating and stuff them into a cathode. The ALCO insulator sped up the heating of the cathode, as in the 227 tube, but the sprayed filaments gave quicker heating and lower cost to the manufacturer. And so profitable enterprise went down the drain! About the same time, an extrusion process was developed for much larger insulators. It used the same powder as the presses, but dampened and placed in a large cylinder with a die on one end. The die was selected to produce whatever size tube was required. A hydraulic ram was brought down on the cylinder, all air evacuated, and the material shot out under pressure through the die. Tubes of material up to four inches in diameter and four feet long could be formed. After drying they could be cut, drilled and grooved to customers' specifications. Solid bars and many other shapes were made by extrusion. Very few insulators, unless of heroic size, were made by a potter's wheel or by filling a mold with slip. This was the common method used by companies making things like toilets and insulators for high-tension power lines, where tolerances did not have to be held to close limits. The soapstone originally obtained from North Carolina was not terribly pure, but sufficiently so for making gas burners. As electronic uses expanded, a need developed to find talc that did not contain iron. Italy supplied much purer talc, but it often blistered on firing. A similar raw material was found in South Africa. Consisting of almost pure aluminum silicate, it came over at irregular intervals as ships's ballast. During World War II, this source began to dry up. The English owner of the mine in South Africa would not help, but he did tell Dad he could come over and dig all the talc he wanted. The first plane flight of Dad's life, then, was to South Africa! He doubled his insurance and bid all of us goodbye forever. Natives were hired, the talc was cut out in blocks and floated down the river on logs for shipment to the U. S. Dad got back also!
I remember when Ford began to order products from ALCO. The first item was a grooved tube used to make a resistor for the primary of the spark coil. Next was a ceramic base for a rheostat to control the brightness of dash lights, then spark-plug cores, then something else until about a third of ALCO's business was with Ford. Then the axe fell! Ford made an offer to purchase the company much below its real worth. Kruesi wisely refused the deal. Ford threatened to withdraw all its orders unless he sold. He would not, so the orders vanished! ALCO sank into the doldrums; things got tight. ALCO sold its insulators to anybody it could, even at a loss. Cornell-Dubilier benefitted; they bought ceramic tubes to put their capacitors in at a rate lower than the paper tubes they had been using. A Thurnauer son, hired just prior to World War II, was a ceramic engineer who had been run out of Germany by Hitler. He was gifted at developing insulating materials of different properties. In a pilot plant, many sorts of raw products were tested and procedures perfected to produce insulation for various possible uses. Always "firstest with the mostest." His crowning achievement was developing insulators, thread guides and cutting tools from titanium dioxide. The process was perfected before it was needed. Titanium dioxide, at the time, was mined only for the making of white paint. Dad agreed to purchase all the raw material that was not used for paint. It was stockpiled until a gargantuan need developed in television for its special properties. Other companies soon became able to make the same product, but they could not buy the raw material. Later another bonanza developed. ALCO was in on the development of the secret proximity fuse in World War II. They outstripped almost all their competitors and were early into producing ceramic substrates for mounting electronic parts. The company was sold in the Fifties to 3M, and Dad retired after 45 years. He had been fired as a youngster by Brock Candy Company because he did not open the retail store one Christmas morning. He was lucky!
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Before World War I the company was called "Sunshine Lava," and was owned by the Thurnauer family of Germany. Sunshine originally made only tips for gas burners. These were machined from solid soapstone [steatite or talc, chemical formula: H2Mg3(SiO3)4].
The products were produced by machining raw soapstone on small turret lathes run by belts from a central power plant. Operators would clamp a small square piece of soapstone in a chuck and bring various steel tools to bear on it, eventually producing the gas-burner tip (or, later, the coil form, spark-plug core, or standoff insulator). Fair wage was 14 cents per hour and talcum powder was everywhere!
After that experience, he was determined to find suitable talc at home. On an expedition to Sedro-Woolley, Washington, he found the needed source and made a local farmer rich. Later, additional deposits were found in California and Montana.