Bill: I think silicone is better than epoxy since it has a little give to it. Because it is flexible when dry, it will maintain adhesion when the both surfaces expand and contract by different amounts either from temperature and/or water adsorption.
Epoxy, on the other hand, drys rock hard. Once dry, it is very rigid and its adhesive bond is liable to break apart if the surfaces expand and contract. Besides being much less expensive by volume, silicone acts like a rubber cushion. It's great for semipermanently attaching the bottom side of a sundial to its pedestal. The sundial can then be removed from the pedestal only with a great deal of effort. Its slow drying time gives you time to adjust the level and direction of the sundial before the silicon sets (Unlike epoxy which dries very fast). First I apply silcone about 1/8 inch thick to the top of the pedestal, then I posistion the sundial on top of the pedestal in its correct final position. I use wooden shims to get the level correct. Then I use a gluegun and squeeze the silicone into the gap on the high side of the sundial. Once it dries, the sundial is "glued" in the correct position. Use mineral spirits to remove excess silicone. Best John >John, I tried out the polyurethane glue (Titebond) on stone, bronze and >glass. I was very unimpressed, and will not use it on my dials. Silicon >glue works much better, as does epoxy. There is a 2 part urethane (not >polyurethane) in the McMaster Carr catalogue, but I'll pass on tying it for >now. > >Bill G. > >
