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).
Laboratory report on achieving a matte finish protective coating for brass switches.
Identifier | ExFiles\Box 38\6\ Scan167 | |
Date | 11th February 1919 | |
R.R. 235a (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. X. 3424. EFC. February 11th, 1919. H13/EB11219. Laboratory. Re Protective Coating for Brass work, with special reference to three miniture switches sent in yesterday. In order to get a matte finish it would be best to have a matte surface on the brass before treating chemically, as this gives a more permanent coat. I send herewith the three switches. It will be noted that two of them are slightly darker in colour than the other; this is due to the fact that they have had a longer time in the Sulphide bath. The small strips show that the polish is due to the original surface since they started on a rough surface, and therefore have a semi-matte surface on finishing. The methods from the Autocar of your note EFC1/AT31119 were tried, but did not give good results. We found that the surfaces as received were coated with Lacca, and this had to be removed before treatment; it would also be better if the switch knobs were threaded before fitting into the switch. HCD | ||