Hi Tony, Great, informative note. I always wondered how these coloured oxide films were created. Thanks, I will try your techniques.
Have you, or others on the list, had any experience using caustic to chemically etch aluminum? We used to make hydrogen to fill party ballons and make mini hydrogen bombs by reacting aluminum foil with a caustic solution (Draino or lye) in a pop bottle. I often thought that this process could be used to etch masked aluminum surfaces to produce the base plate for a horizontal dial. I never did reduce the idea to practice as the hydrogen ballons and bombs were more fun. Were you more successful? Roger Bailey N 51 W 115 )At 12:32 AM 11/11/99 +0000, Tony Moss wrote: >Fellow Shadow Watchers > >Continuing my occasional series of practical approaches for metal sundials here is a distillation of my personal notes on anodising aluminium prepared over many years of practical experience. Aluminium has a normally dull and soft surface but anodising can transform this into beautiful multi colours with a weatherproof surface hard enough to resist all but the sharpest instruments. > >Interested? Then read on! > >
