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).
Letter to Muirhead & Co. Ltd. requesting assistance in finding a suitable compound for filling and sealing ignition coils.
| Identifier | ExFiles\Box 167\3\ img143 | |
| Date | 26th January 1939 | |
| Insulation 6110 EXPERIMENTAL DEPARTMENT. Rm{William Robotham - Chief Engineer}/RC.{R. Childs}10/JH. 26th. January, 1939. Muirhead & Co.Ltd., Elmers End, Beckenham, Kent. For the attention of Mr. J.V.Fole. Dear Sirs, With reference to your letter of the 21st. Jan. We thank you for your kindness in offering to help us in our search for a suitable compound for filling and sealing off our ignition coils. The coils have a bakelite case and are subject to temperatures of 80° - 90°C. We are at the moment using paraffin wax, the only disadvantage is its low melting point. We have in the past, tried both 'Halowax' and 'Seekay' wax, which are both good. Unfortunately they are both a chlorinated wax, the fumes of which are liable to set up dermetic effects on the operators, also the M.P. is not so low as that of paraffin wax. We have tried some bitumastic compounds, but these are not easy to handle, as their melting point appears to rise appreciably after once being heated, and temperatures much above boiling point blister the bakelite. We shall much appreciate any help you can give us in this matter. Thanking you in anticipation. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||