Hi Mike, I think Tony's idea of moulding the dial is a good one for DIY construction. As another alternative to cement, there are powders which make up to a stone substitute, like an outdoor plaster-of-paris. I have used it for small items and it is very good. Available from arts and crafts suppliers.
For commercial dials that will last several lifetimes, I have been investigating vitreous enamel on steel. This is the technique that was used on garage advertisements for petrol etc in the 1920's, as well as railway signs. Not something you can do at home, but I got a not unreasonable quote to make some 1.5metre diameter dials. Good luck with the dial - we will expect a report and picture in due course! Regards, John ----------------------------------- > Dear Friends, > I seem to have talked myself into making a dial in The Gambia, about 13° > north of the Equator. The design is fairly straight forward. In brief it is > to sit on the ground on the south side of the swimming pool at the hotel. It > will recline so as to be visible from the north from a lying position around > the pool. The dial has been calculated for 45°N therefore 45 - 13 means that > its plate will be sloping about 32° to the horizontal. The distance from the > pool is about 10m, therefore it needs to be of some size. I am planning on > making it about 2m across. > The main problem seems to be the choice of materials. I have ruled out > wood due to the termites in the area. I have also ruled out paint as the sun > is so very hot most days - except for the 3 months of rains. It has to be > constructed by local labour with minimal materials available. > I am planning to be there to set it up and work out the delineation but I > want to be sure that we have all the materials to hand to build it within a > few days. > At present my thoughts are to make it from concrete, preferably off site, > so that it can be laid in position, and dare I say it?, enable me to make > small adjustments later if necessary. This will probably mean that it will > have to be made in up to 4 parts plus the gnomon. The ground on site is > basically sand. I originally considered moulding in the hour lines, numerals > etc. but think that this would be too much for the personnel involved. My > latest thought is to make just a flat plate and apply the hour lines as > strips - of wood? and house door type numerals. At least, when the termites > eat these strips, they can easily be replaced! > Therefore I am asking for any other suggestions that may be more > appropriate. I am sure that several members of this list will have made > dials for the tropics and eagerly await their comments. > > Regards, > Mike Cowham. > Cambridge, UK.
