It is surprising how few articles come up with epoxy that actually state what to use… So on my own I have been experimenting with CA and several other epoxies. While CA is intently strong and fast i have popped off stones that were just too close to the edges to let them go. JB weld products have been a failure and I am working with them to find a product that actually works for faceting purposes. Dev-Con on the other hand is at the moment the single best product that I have worked with. So much so that instead of the 24 hours wait and see I have now been able to dop 7 stones with what I believe to be reasonable certainty of successful cut and transfer. I will attempt to update further but at the moment if you are struggling with epoxy dev-con has been the most successful for me.
Have you tried EPOXY 330?
not yet but the dev con is working well.
Dopping methods are a contentious issue with faceters. The main reasons for failure with dopping waxes is that the wax and stone do not get hot enough to bond or the wax gets too hot and burns. I don’t find the epoxies a good substitute myself because they take a while to set and they are not really rigid, either. These problems are avoided with a hybrid dopping method. One gets wax on the dop soft enough to take an impression and pushes the stone into the wax. If the wax is warm, but not hot enough to bond with the stone, it will separate from it, but the stone leaves an impression. One can then apply a CA glue (superglue) to the stone and bond it to the waxed dop. A little nail polish is used to coat the bond to be sure that water does not degrade the wax to superglue bond. This produces a sturdy bond without having to heat the stone very much or worry about an insufficiently hot wax which can result in a weak bond. If the stone should come off the dop, the wax will break away in a unique manner and it is easy to reattach the stone exactly in position by using superglue again to bond the two parts of the broken wax.
Perhaps not the information you were seeking, but I have found this the best dopping method and my late mentor, Will Smith, taught this to all his students in the Middle Tennessee Gem and Mineral Society faceting classes for many years. -royjohn
It’s already been suggested here but I’ll add to that. Not sure it would help with dopping. I just use green dop for my limited requirements in polishing This may hinder not help but here’s my take on 330.
I’ve used EPOXY 330 for over 3 decades and it never failed in anyway. I even have some items I used it on made back then. Can be polished too under low speed.
Does not weaken, fade, yellow from clear, or change color in photo work I’ve sealed. Seals I made tested to 500 feet below sea level while out tuna fishing. Used it to set cabs without failure. Used it to stop accents from falling out in pesky settings. Set’s fast but I use common heat lamp to speed that up. Light bulb works too. Only draw back I have is you can’t resize rings unless you get the cab out. Hard to do. Must soak in acetone long.
Tried a thousand other types and brands that failed every time in one way or another. My bench is never without EPOXY 330. GROBET USA makes it but you have to go to a distributor to get it.
HOPE THAT HELPS. GOOD LUCK
update, while dev con does seem to give a strong bond its horizontal strength seems to be quite low, after losing adhesion on the girdle cut twice I checked all the others and each failed horizontally with only reasonable pressure. I am currently looking into 330 but for the moment relying on CA for the direct bond and strengthened with the dev con. To those that use wax I understand and have plenty of it but am attempting to find a fully reliable dop solution that requires NO heat at all to use or to remove.
I use Devcon 5 minute epoxy almost exclusively. For a faster cure, I put the dopped stone in my transfer jig and put in the oven. Turn on oven, heat to 130-140 degrees F, then turn off. Residual heat ramps up to about 200F. Take out in one hour and get to work as epoxy is fully hardened. I’ve never lost a stone due to heat as I think the surface gets an even, slow heat and equal cool down.