Gluing stones and settings together can be either easy or very frustrating. No matter what glue you use, glue cannot successfully adhere to a smooth shiny surface as it needs something to grip onto. Over the years, we have narrowed our glues to two main types.
1) Epoxy Glue - This type has two tubes. To use this squeeze equal amounts onto a shiny cardboard, mix with a toothpick and then apply. Epoxy glues tend to operate on the basis that the faster it dries and the clearer it is, the more brittle it becomes which can cause failure. Epoxy 220 and 330 are the standard that has been used successfully over the last 20-30 years.
Epoxy 220 - is slightly amber in colour and is slow drying which makes it very strong and resistant to shock. It sets in a 1/2 hour and cures overnight. It is great to use where the glue does not show.
Epoxy 330 - is water clear, sets in 15 minutes and cures overnight. Its is the best epoxy for jewellery where the glue may show.
2) Cyanoacrylate Adhesive (like crazy glue) - These glues are water clear, tend not to yellow and set very quickly. From our experience we have found "Hot Stuff glues to be excellent. It comes in three different forms.
Hot Stuff Original - Instant Glue (Red Bottle) - This is a thicker glue (like Syrup) that fills the gaps between the pieces such as a setting and stone. This glue sets in about 30 seconds. It is the best for most jewellery applications.
Hot Stuff Special T (green bottle) - This is a much thicker glue (like honey) which works great when there is more gap between the 2 surfaces. It sets in approx. 60 seconds.
To guarantee the best results for gluing parts together, the two surfaces must be sanded or scratched to allow the glue to grip to the surface. For stones, we use the side of a worn out diamond drill bit to rough up the surface. Sand paper may also work. You can't over scratch the surfaces.