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Some components are too fragile, too awkwardly shaped or too highly finished for workholding by conventional clamping. One alternative to the specially made fixture – always slow and expensive to produce – is to use a bismuth‐based low‐melting‐point alloy as the work‐holding medium. Alloys specialist Mining and Chemical Products says that with melting points as low as 47°C and the unique property of expanding on solidification, fusible alloys can often provide a quick and cost‐efficient means of turning difficult work‐pieces into something much easier to hold for machining and handling. The low melting temperatures eliminate risks of heat damage to work‐pieces, while the non‐shrinking characteristic ensures extremely solid support even during the most arduous machining operations. According to MCP, bismuth alloys are also highly economic to use. They can be melted down and used again repeatedly. This is not true of other work‐holding media. Moreover, since many of them contract on solidification they cannot provide the firm and all‐embracing support that is almost always needed.

Reviews the state of fusible‐core technology and describes various techniques: core casting, overmoulding and melt‐out. Suggests that fusible coring for small runs can make a product financially viable.

“Concentrated” assault on corrosion. A production new to the U.K. anti‐corrosion market but well known in mainland Europe is “Multi‐Function”, an all purpose chemical with water dispelling, lubrication and anti‐corrosion properties developed by the West German Trost organisation.

A researcher at Northwestern University's McCormick School of Engineering and Applied Science (Evanston, Illinois) has developed an X‐ray device that is believed to be the first practical means of detecting corrosion hidden beneath the surface of an aircraft's body. When the “virtual core drill” is positioned against the side of an aircraft, a computer screen shows an image of the layers of metal under the surface of the skin. If one or more of those layers are corroded, the amount of corrosion will be recorded on the screen, to an accuracy of 1/1.000 of an inch. The virtual core drill or, more technically, a Compton backscatter depth profilometer, was invented by Larry Lawson, research scientist at the McCormick School's Centre for Quality Engineering and Failure Prevention. The device sends con‐trolled X‐ray beams through the plane's body and detects those X‐rays that are deflected back at an angle near 90° from each layer. Today, whenever corrosion is detected on aircraft, the section must be dismantled, the layers pulled apart, and a micrometer used to measure the thickness. If the corrosion represents more than 10 per cent. the part must be replaced. The virtual core drill can eliminate the downtime and the damage that occurs when aircraft have to be torn apart for inspection. The new device includes a 200lb scan head, which is attached to the plane using feet shaped like suction cups while supported by a flexible boom mounted on a vehicle resembling a fork‐lift truck. The vehicle moves the scan head up and down the aircraft. The drill is equipped with the most sensitive detector known, the sodium iodide scintillator. The drill provides the same kind of information, layer by layer, as would be provided by cutting a plug out of the aircraft with a core drill, except that the aircraft is undamaged. Radiation exposure also is minimal.

“Epimastic” chosen by the Central Electricity Generating Board. Wailes Dove Bitumatic plc recently supplied the second half of a large order for Epimastic L1078 Coal Tar Pitch/Epoxy coating for the C.E.G.B. power station at Kingsnorth, Kent.