Are you by any chance tumbling earrings with posts? That can leave
small spiral marks on things. Also, if these are cast pieces, perhaps
the problem is in the casting.
Marilyn Smith
Hi. Pits can be the result of a porous casting, or from overheating
solder. If the problem is not too severe in the casting, you can use
a “bent nail” to repair the problem. You mount a steel nail in the
flex shaft, and give it a slight bend. Make sure you grind and
polish out the end of the nail so you have a very smooth surface and
no edges to dig into the metal. You then fire up the flex shaft with
the bent nail, running it very fast, and give the porous part of
your casting a gentile work over. This burnishes down the surface of
the casting and can sometimes salvage the piece. A light sanding and
polish will tell the results. If this fails, it’s back to the scrap
heap for your piece.
On the overheated solder, there is little that I know of to fix this
problem once it shows up. This is a problem that you can prevent,
not cure.
Don