From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Methods of protection for the exhaust system against corrosion and scaling.
| Identifier | ExFiles\Box 93\1\ scan0056 | |
| Date | 16th November 1936 | |
| E.{Mr Elliott - Chief Engineer} Dept. Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} Hl/Aspley. BY/EM. 8223 BY.6/G.16.11.36. EXHAUST SYSTEM. ----------------- I wish to make quite clear that there are two methods of protection put forward on the chassis with the object of :- (a) Eliminating the use of Staybrite. Under this heading aluminising by the Schoop process is resorted to in order to reduce the cost at present incurred by the use of Staybrite pipes, and at the same time avoid the pipes scaling away where they are lagged if mild steel only is used. The scheme under this heading is therefore ordinary mild steel piping, protected on the outside by aluminium deposit by the Schoop process. (b). Water corrosion in the rear silencer. Under certain conditions of service viz. when the car is run by a Doctor, the rear silencer acts as a condenser and the temperature is never high enough to ensure the condensate being re-evaporated and cleared away. To overcome this definitely we are at present trying out the Web system at Mr. Wymann's suggestion. In order to make certain of the position, we are not only running rear silencers treated inside and outside by the Web deposition process, which is a system of plating, but we have arranged for the Laboratory to carry out salt spray tests on parts treated by the Web process and to compare these with :- (a). Mild steel protected by cadmium. (b). Mild steel protected by zinc. The Web process, according to its inventors, consists of depositing electrically a mixture of certain metals, amongst which we ascertained were aluminium and cadmium. We are not at all convinced until we have carried out a complete set of tests whether their claims are in any sense justified, and testing such a system is of necessity a long drawn out process. It means, therefore, that we will have to depend upon the salt spray tests. BM BY.{R.W. Bailey - Chief Engineer} | ||