LETTERS TO OMNIBUS
Bundy Tube
Your article on the Bundy clocks in Birmingham (Omnibus 139 - January 2001) was most interesting. However I want to draw your attention to a slight mistake.
In response to a letter by Bernard Minton, Willenhall, the editor states: "The Bundy tradename appears on an entirely different product, a type of reinforced (double walled) copper tubing produced originally by the Yorkshire Copper Works." This statement is quite misleading because Bundy tubing is a type of steel tubing not copper. The mistake might not matter except that in the automotive sector there is a type of copper tubing used to replace steel Bundy tubing that is known as Kunifer. The mistake is likely to cause or perpetuate confusion about these quite different types of tube.
The following description of Bundy tubing is from the Copper Development Association web site, under 'Types of Tubing':- "It is produced from continuous copper-coated steel strip in the cold rolled, soft annealed condition formed into a fully overlapped, resistance brazed, tube. The final tube will have a copper coating on its internal and external surface to a depth of 5 - 50µm. To give some extra protection the finished tube may be coated externally with zinc or terne (a lead/tin alloy with 5 - 25% tin)." Thus Bundy tubing may be described as a thin-walled steel tubing.
In the automotive sector, corrosion problems with steel tubing led to the development of a cupro-nickel alloy tubing with superior corrosion resistance. This is marketed under the trade name 'Kunifer'. Kunifer tubing is formed from a 90% copper 10% nickel alloy (known as 90/10) and now widely used for automotive brake pipe applications.
Hope this helps.
Roger Higgins (by e-mail)
We stand corrected on the definition of Bundy tube, but does anyone know if there is a connection between the origin of this product and Willard Bundy? Editor
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