Abstract: An aqueous composition for the treatment of surfaces such as metals particularly aluminum, comprises a tetraalkyl silicate or a monomeric or oligomeric hydrolysis product thereof, and an inorganic passenger powder below 100 nm diameter such as fumed silica, both in dispersion in a fluid aqueous medium. The composition can be applied as a conversion coating to improve the adhesion of subsequently applied paint, lacquer or adhesive. Non-aqueous intermediate products comprising the silicate component and passenger powder can be diluted with water to make the coating composition.

Abstract: An adhesive composition constituted of a mixture of a one-part heat-curable adhesive and a substantially water-insoluble indicator material which is substantially unreactive with the components of the one-part heat-curable adhesive (i.e. curable resin, heat-activatable curing agent for the resin and accelerator) but which has the ability to produce a color change in the composition on curing of the adhesive. Preferably, the adhesive is a one-part heat-curable epoxy adhesive system. The use of the adhesive composition enables a visible detemination of the point of cure of the adhesive.

Abstract: The invention concerns a method of forming a joint between aluminium workpieces. These carry an artifically applied e.g. chromate or anodic oxide coating on their surface. A curable adhesive containing up to 40% by weight of particulate filler having a maximum particle size of 300 microns is provided between the workpieces to be joined. Resistance welding is performed using a welding electrode whose tip has a surface with an average roughness depth of at least 10 microns. This increases electrode life and makes it possible to use lower welding currents than previously recommended.

Abstract: A method for the repair of an aluminium metal structure that has been damaged involves applying a heat-curable adhesive between faying surfaces of components and curing the adhesive by means of infra-red radiation. An infra-red absorbing coating, such as a black lacquer, is applied to an exterior surface of the structure to be heated, and is effective to confine heat supplied to the desired region and to avoid overheating, both of the infra red lamps and the remainder of the structure.

Abstract: A metal-working lubricant comprises an aqueous emulsion of (a) a long-chain aliphatic ester, amide, alcohol or acid, and (b) as a fugitive emulsifier an ammonium or volatile amine salt of a long-chain aliphatic acid. On application to sheet, e.g. of aluminum metal with a chromate or anodic oxide protective surface layer, the water and ammonia or volatile amine evaporate to leave a storage-stable hydrophobic lubricant. The sheet can be formed or made into adhesively bonded structures of shaped components.

Abstract: A lubricating composition for press forming consists of a lubricant dissolved or dispersed in a volatile liquid medium, wherein the lubricant comprises at least one ester of a polyhydric alcohol having two or three hydroxyl groups of which one or two are esterified with a long chain carboxylic acid and has a melting point above ambient temperature but low enough to permit removal from a metal surface by an aqueous alkaline cleaner.The composition is useful for forming structures of shaped aluminium components on a production line.

Abstract: A lubricant for metal forming comprises a dispersion of particles of a waxy material in a solution or dispersion in a volatile liquid medium of a monomeric organic carrier which is a solid or a viscous liquid at ambient temperature. The particles may be 5-25 microns, the volatile liquid may be xylene, the carrier may be an ester with a MW below 320 and the weight ratio of particles to carrier may be 1:1 to 6:1. The waxy particles provide good lubricating performance without coalescing under load. The lubricant is compatible with adhesive and is easily removed from a workpiece.