Tumble polishing cast iron

Hi Folks, Although this isn’t a jewelry question it does fall into an
Orchid area of expertise, namely. polishing metal. Any help will be

In brief, I have a friend who runs a foundry. They produce cast iron
things. Small ornamental items, say in the size range from a large
button to about the size of a cigarette pack, have hitherto been taken
through four stages of grinding to prepare the surfaces to be chrome
or nickel plated.

My friend is wondering whether it might be possible to tumble polish
(or smooth, at least) these small cast iron parts and so dispense with
the labour intensive and costly manual grinding process. He’s asked me
to run some experiments.

Rather than re-invent the wheel in experimenting from ground zero I
wonder whether any Orchideans might be aware of a good book on
industrial tumbling for metal preparation.

Any other advice? Can components the size of a cigarette pack be
successfully tumbled at all? Should he use a rotary or a vibratory
tumbler? The aim is to smooth and clean the surfaces prior to plating.
So I don’t suppose grit would be appropriate, as it would likely erase
surface detail. What medium should he use?

Any and all advice is welcome, welcome, welcome!

Cheers & thanks
Hans Duirstling
Moncton, Canada

The best source of tumbeling is from Rio Grande. It
makes a difference in the tumbeling equipment you use and the amount
of metal that you need removed from the piece as to what products you
use at each ofbthe stages .