I have a CIJ jag with some new Seymour Duncan antiquity pups with the same problem. The feedback is really harsh. Anyone here have any experience wax potting?

I had this same problem when I was installing my new Antiquity I's in my jag. The only way i could get the solder to stick to the claw was to take a blow torch to the claw and melt the solder to it.
The ground still doesn't sounds perfect (still a bit of hum), but that could just be my imagination.