Silver clay is easy to repair. The fresh low-shrinkage clay applied to fired silver seems to stick pretty well. This is not the case with bronze and copper clay. Fresh clay doesn’t stick, and if it does, once it’s dry it tends to separate and peel off. So here is what I’ve found:
Applying the Clay
Spit helps to adhere fresh clay to fired clay. Place some saliva on the spot to be repaired and the clay will stick and won’t peel off when it’s dry. You can smooth the repaired area with some saliva on you finger, but please, if there’s clay on your finger, don’t put it back in your mouth!
When you do a small repair, the first phase of firing can be replaced with torch firing. Fire the repaired area with a torch for about 30 seconds, then move on to the second phase. That saves a lot of time and energy. You can put aside a few pieces that need repair, torch fire them and then fire them together according to the directions for the second phase of the firing schedule.