GB572010A - Improvements relating to the tinning and soldering of sheets or articles of aluminium or aluminium alloy - Google Patents

Abstract

572,010. Soldering. LOUIS, L. Aug. 17, 1943, No. 13357. [Class 83 (iv)] A tinning or soldering composition for use in soldering sheets or other articles of aluminium or alloy thereof comprises from 31 to 42 per cent or thereabouts of tin, 5 to 9 per cent of zinc oxide, 20-27 per cent of zinc chloride and 24 to 32 per cent of ammonium chloride, all in powder form with water of crystallization up to 15 per cent of the mixture. One composition may be made by melting tin powder and stirring therein three parts of zinc oxide to 15 parts of tin and after cooling, powdering the mixture and adding to two parts thereof 10 parts of zinc chloride powder. 12 parts of ammonium chloride powder and 16 parts of the aforesaid tin and zinc oxide mixture. In another composition, 50 parts of tin powder and 37.5 parts of ammonium chloride powder are mixed with 108.8 parts of a powder formed from the residue after the manufacture of zinc chloride from scrap or other zinc digested with hydrochloric acid and containing 32.3 parts of zinc powder, 8.8 parts of zinc oxide powder, 29.9 parts of zinc chloride powder, 13.3 parts of lead powder, 9.15 parts of lead chloride powder and 15.35 parts of water of crystallization. The powder is applied to the surface of the work which is then heated by a blowlamp &c. until a dross appears and then a dense smoke with the formation of a dull white deposit, i.e. to a temperature of' about 230‹ C., whereupon the surface is rubbed with an iron or steel tool and the tinned surface then cleaned. The tinned article may then be soldered with ordinary solder by an iron to a similarly tinned aluminium &c. article or to an article of another metal suitably tinned.