Sorry for the delay in response Trullock. Sealing the pearls was the biggest challenge for me with the project. I tired a number of methods - everything including hot glue, silicone sealant, 5-minute epoxy, silicone stoppers, CA glue, a few other adhesives, and even trying to flame seal the small hole. The best solution I found was UV-curing resin. I used the Bondic brand, but I know there are quite a few others. It worked well because it cures almost instantly and forms a pretty tight seal around the monofiliment passing through the pearls. That said, it isn’t perfect and there is always the risk of the resin detaching from the glass and breaking the seal (which has happened on a few of the pearls over the last year). I still believe there is a better solution out there, so please share if you find one!