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).
Outlining comparative tests for soft deposit (Harcourts type) and bright chromium plating methods.
| Identifier | ExFiles\Box 154a\1\ scan0216 | |
| Date | 24th September 1930 | |
| RECEIVED SEP 24 1930 HS{Lord Ernest Hives - Chair} X4442. H1/Mr. Aspley. c. Wort c. Hs.{Lord Ernest Hives - Chair} CHROMIUM PLATING. After examining the number of pieces which have been treated by the bright plating method, I think we are sufficiently far advanced to make comparative tests of :- a/- Soft deposit (Harcourts type). b/- Bright plating. We must have good nickel base deposits which should be of a thickness suitable for both types, and in addition the chromium deposit must be the optimum for resistance in each case. I would suggest for bright deposit we should have after polishing at least .002 of nickel, and it must be produced with good adhesion. The chromium should be between .00003 and .00004 inches in thickness. I then want the pieces, which should be fairly intricate, say either hub caps or the bonnet catches, subjected together to the salt spray until one of them shews distinct signs of breakdown, at which stage I would like to examine them personally. The test should then be carried further until the second piece fails. This will give a direct comparison of the quality of the two deposits. It is urgent and important to get a decision from these tests to enable us to decide whether to continue the soft gray deposit or adopt the bright method of depositing. BY.{R.W. Bailey - Chief Engineer} | ||