What sort of damage does aluminium do to sterling silver?
In case James doesn’t reply.
Because the aluminum has a much lower melting point than sterling it
melts early and starts forming alloys with the sterling in the local
area of the aluminum.
This effect causes deep pitting and gray areas (if I recall
correctly they are pretty hard) that are very difficult to remove,
and usually permanently damage the piece.
In my shop I use a great variety of metals including three types of
aluminum. I usually clean pieces ultrasonically before soldering and
haven’t had any problems. I never mix saw blades or files, but I do
I use my burs with bees wax and they are all carbide. The ultrasonic
will remove anything that isn’t mechanically bonded to the
substrate. I am drawing from personal experience and believe that the
differences in the cutting process between files and saws, and burs
is what makes the difference.
I believe that files and saws will embed minute pieces of Aluminum
into the substrate very slightly below the surface in-part because
they don’t cut so cleanly (even new, they roll the chips into the
cut); the burs cut more like milling cutters, pushing the chips
ahead and taking any aluminum with it.
Without the benefit of an ultrasonic I would be extra careful, but
still a good cleaning with a brush should do. I bow to James if he
As a side note steel will not damage sterling, but will stain it,
until it is sanded or polished out.
Also as a side note, non of my burs come from jewelry supply but
rather industrial; I use burs from a company called Metal Removal
purchased from Rutland (http://www.shoprutlandtool.com/).
All the best,