ferromagnetic and would not provide much attractive force to a magnet; when they are cold-worked, as in rolled sheet, they are only slightly ferromagnetic but would still not provide sufficient magnetic attractive force for this approach to be successful.
Some 400-series stainless steels are ferromagnetic, but those that are also rust slightly and are not what you would call "stainless."
Another approach would be to place a painted steel plate on the inside of the glass. If you then use a coated (anti-corrosion) rare-earth magnet on the gnomon, there would still be significant attractive force through the glass. Neodymium-iron-boron magnets give you the best attractive force for the cost; samarium-colbalt magnets can be "stronger" but cost substantially more due to the limited availability of cobalt (not the samarium). Or, the magnet could be on the inside and the steel plate on the outside.
Larry McDavid John Carmichael wrote: snip
Anyway, I've been thinking that for some future project, that it would be possible to attach the gnomon to the SGS using a magnet. If a piece of stainless steel were in the stained glass design, and if the gnomon baseplate were a magnet (or vias versa), then you could secure the gnomon to the SGS without fear that it could crack the glass. If somebody bumped into the gnomon, it would simply fall off, avoiding any damage to the glass.
-- Best wishes, Larry McDavid W6FUB Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland) -
