Non-Chemical Polishing gold using steel ?

[Noxx]

Hello guys.
I saw a video on youtube of a gold coin company polishing its gold with steel beads (balls). I was wondering if I could do the same. I already have a rotary tumbler made for polishing gems, stones, etc.
Any idea of the ball size I need ?
Do you think Chrome Steel balls would work ?

Thanks

 

[Harold_V]

Noxx,
I think you're looking at what is commonly called burnishing. Media is available for the purpose, and includes some really strange shapes, so even tight corners can be accessed.

I suggest you investigate media made of stainless to avoid any tendencies of rusting.

It takes quite a few hours of operation to improve surfaces. Burnishing is generally used for polishing a large number of pieces, not just one. One of my customers used the process routinely in polishing a particular sterling silver ring he manufactured.

Harold

 

[peter i]

I do it routinely on my silver jewellery.

Stainless steel shot, a few drops of dishwashing detergent, water and a “Lortone” rock tumbler. It puts a very nice final shine on the silver, and when making chains, it’s the only way to go.
And it will stand in the corner humming, while I do something much more entertaining than polishing.
http://www.ottofrei.com/store/product.php?productid=5769&cat=0&page=2
The pins are approx 10 mm long.

Jewellery supply houses sell the shot.
You can use normal steel shot, but they will rust and are generally discouraged.

 

[Bernie Foley]

Hi Peter i and friends,
I used it on my sterling braclets,they were 10 gauge with out stones.
I also used it to put spring into ear posts after welding them to the cup.
24 hrs using round ss shot and soap.I made the sterling pins just as stiff as ss pins. I only did 14k+ and sterling jewelry.
Have a great day!...Bernie

 

[goldsilverpro]

A friend made 24K jewelry, which was very soft. He work hardened the surface of the gold using very small SS beads in a vibratory bowl with soapy water as a lubricant. It also polished the gold.

 

[Bernie Foley]

Hi Gsp and friends,
yes tumbling or shot polishing,burnishing will workharden silver&gold. I used it in the jewelry trade on my stuff to stiffen the earpins and posts.
all of my products went through it. gives a somewhat satin finish and blends in any tiny scratches.It leaves a nice finish that lasts well.
I have a cnc mini-mill and am thinking of trying machining the fingers and boards of plated traces. Using a carbode mill and turning slow
with coolant and trapping the gold&copper chips in a filter......Sorry that should be a carbide mill ! Will let us all know how i do with it!..Bernie