Bob

Re: Polishing finishes

Hi everyone,

I'm interested in expanding my knowledge and seeing what other industries are doing and how they are doing it.

My company manufactures gold jewelry.  We use the conventional polishing compound and rouges with felt wheels and cloth buffs to obtain our high gloss finishes all done by hand.  I feel it can be better, whether mechanical or hand done and I'm looking for suggestions to try and test.  I'm looking for several things; 1. a really high reflective finish more so than the mirror lap I am now acheiving, 2. other finishes, for example I currently use satin, stone, and glass bead matting finishes.  My production is mostly a hand processing operation but I would be interested in both hand and mechanical methods.  3. what type of media and material is best to use in a barrel or disc finishing machine?  4. Can applying a plating, (I would need to use gold plating materials) make an item look even more reflective?  5. I have heard about ELECTROPOLISHING, what is this and is it something I should try? 

Any and all suggestion will be test and greatly appreciated.

Thanks, Bob

Labrat

Re: Polishing finishes

Electropolishing involves a reverse current applied to stainless steel parts in a mixed acidic solution, which dissolves the "peaks" to match the "valleys" on the surface to obtain a smooth bright surface. This application is much to aggressive for gold and would severly etch and dissolve the part.
There are both liquid and powder commercial burnishing compounds that could be used in an oblique type rolling barrel, in which the parts burnish each other as they roll and slide in the barrel. Media of varying materials can also be introduced for different effects. For quicker results, you could investigate using a small vibratory bowl for burnishing.

Bob

Re: Polishing finishes

Labrat,

Thanks so much for responding. 

I was planning on testing some barrel tumbling processes.  Do you have any recommendations on materials that would provide the best result?

As far as the acidic solution used for electropolishing, would it possible to dilute the solution to an aceptible level?  or use other acids to acheive the same results for gold?  I beleive it is the peaks and valleys as you say that if equalized will provide a higher reflective surface.  I would like to pursue this option further.