Technical report on the testing of I.C.I. 'Seekay' wax for filling ignition coils to improve reliability.
| Identifier | ExFiles\Box 164\5\ img241 | |
| Date | 23th September 1935 | |
| Hs {Lord Ernest Hives - Chair} /Wst.4/MA.23.9.35. FILLING OF IGNITION COILS WITH I.C.I. "SEEKAY" WAX. For some considerable time we have been on the look out for a suitable high melting point wax filling for our ignition coils which would be suitable for normal use on the chassis. The idea of this wax filling is to exclude all air from the windings of the coil, especially the secondary winding where the presence of any oxygen causes corrosion to occur and the subsequent break down of the winding. I.C.I. have now produced a wax named "Seekay" which has a high melting point of 123°C. A quantity of this wax was obtained and tested electrically and also tested for its effect on the performance of the coil. One coil was filled with this wax and tested for 500 hrs. on the bench and then cut open showing the wax to have made a very satisfactory job of the sealing of the coil. A slight decrease in the coil performance is noted due to the use of this wax filling which we attributed to the fact that this wax has a higher specific inductivity than paraffin wax but we consider the effect to be negligible in comparison to the advantages gained due to the sealing off. A record of the tests carried out with coils filled with this wax is as follows :- (a) 2 coils filled with "Seekay" wax were fitted to 3S1 SpectreCodename for Phantom III chassis and run 22, 391 miles without any failure, the coil performance being satisfactory. (b) 2 coils were filled with this wax and tested for 500 hr. endurance test on the bench in connection with a test recently completed for aero battery ignition. In all cases the coils did not fail and were in satisfactory condition at the conclusion of the runs. In comparison an ordinary standard coil run on a similar 500 hrs. endurance test failed regularly approximately every 150 hrs. due to the top layer of the secondary winding corroding and causing a short circuit of that layer. These tests show that this wax impregnation improves the reliability of the coil considerably and in view of the extra work these coils will have to do on the SpectreCodename for Phantom III chassis should improve the reliability when used on this chassis. Hs {Lord Ernest Hives - Chair} /Wst. | ||
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).