52420

How to brighten glass beaded stainless steel  

June 19, 2009

I have a bunch of stainless steel parts that have been heat treated and then glass beaded. My customer would like me to get the parts to look shiny again. I let him know that he would have to get them electopolished. I just wanted to make sure that this in fact is true. Someone told me soaking them in a 20% solution of nitric would do the trick.

Any help would be appreciated.

Jay Harms
Technical consultant - Hamilton, Ontario Canada

Hi, Jay. I think that either mechanical polishing or electropolishing can restore a full reflective surface. Glass beading dimples the surface to reduce specularity, so I think you need a process that smooths out the dimples, and I doubt that nitric acid will restore brightness (I haven't tried it though).

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Nitric will not restore the brightness.
I somewhat doubt if electropolish will restore full brightness over beaded SS. It might, but you will have to send out some test pieces to a job shop to find out. Mechanical polishing will work fairly well IF they are flat pieces. It may take a combination of mechanical and electro polish to fully restore the brightness.
None of this is going to be cheap. Is the customer willing to pay for it, or is that company looking for a better looking part at your cost?

James Watts
- FL

Electropolishing WILL brighten the finish of glass beaded parts. The degree of brightness depends on the length of time the part is electropolished. It will not however, produce a MIRROR finish.
If this is acceptable it will be cheaper to run a double or triple process time in the electropolishing tank rather than pay labour to mechanically finish the part.

Cliff Kusch
electropolishing shop - North Vancouver, BC, Canada