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 detailing the analysis of severe corrosion found in a radiator after only four months of service.
| Identifier | ExFiles\Box 27a\3\ Scan024 | |
| Date | 6th May 1929 | |
| K4516. am/NRC.{N. R. Chandler} H15/EA6.5.29. Laboratory. c to Bv. Report No. L1501. Re Radiator Corrosion. We have analysed the sample of the corrosion products taken from the radiator which was badly corroded. The tubes of the radiator were in some cases so badly attacked that it was possible to push holes in them easily. The corrosion products collected in the top portion of the radiator and reduced the circulation of the water, which soon boiled. This corrosion is of a serious nature seeing that it has taken place after only four months service. The analysis is as follows :- Zinc ---------- 0.96 % Chlorine ------- Traces. Silica --------- 1.40 % Lime ----------- 9.12 % Magnesia ------- 1.24 % Iron Oxide ----- 11.68 % Alumina -------- 8.52 % Sulphates ------ Absent. Tin and lead in the metallic state from the solder, were also present. The unusual features of the analysis are the lime and alumina contents. The presence of the lime must be due to the addition at some time or other, of hard water, as neither soft water nor distilled water contains it in appreciable quantities. Incidentally the low chlorine content indicates that the water is free from contamination by sea water. We mention this because the car was used in and around Grimsby. With reference to the alumina content, this may be due to washing out with caustic soda which would act on the aluminium cylinder head. The only other possibility -(that it was introduced as clay) is obviated by the fact that the silica content is low. Another very unusual feature of the case is that in spite of the fact that the radiator was washed out with dilute caustic soda solution to clean it, a little of the corrosion product, when boiled with water gave a distinctly acid reaction. We cannot explain this except by saying that somehow an acidic substance has been introduced. We think it probable that the rather high acidity of the water is the cause of the trouble, as this would certainly tend to accelerate local dezincification of the radiator tubes. An analysis of the radiator tubes would be of doubtful value, owing to the local dezincification. We could attempt this, however, if desired. We would also mention that the absence of chlorides | ||