Stainless steel surfaces sometimes have quite a bit of black material lodged in their tiny crevices. I don't know what it is - maybe residue of the binder used in the first printing stage? I'm pretty sure it is neither steel nor bronze. The amount of offending material varies from print to print. It is especially annoying on flat surfaces. Buffing, wire brushing and steel wool brushing do not seem to have much effect. I had some success scrubbing and washing it away with Boraxo. That was only partially effective. Does anybody know what this material is? Is there a solvent for it, or any reliable method of removing it?
The material you are referring to is the residue of abrasive media used during the polishing procedure. About the only way to remove it is to pick it out with a sharp pointed tool. A common sewing needle, held in a pin vice or embedded in a short length of wooden dowel makes a great removal tool. Really anything with a hard sharp point will work. -G
If you can get your hands on some jewelers ultrasonic solution, that should work well to get the black off, Or making your own works too... Bowl of warm water, splash of Ammonia, and a dab of liquid dish soap like Ajax or Dawn. Then just use a soft or medium tooth brush (one that you dont plan on using on your teeth) I've had a lot of success with this, @GlenG: Love that trick, i also use it when i'm not worried about putting a scratch on the item i'm working on Also, GlenG, are you on Ganoksin's Orchid mailing list? LOTS of great tips from there Ray
There are several abrasive medias employed in the shop for tumble finishing SW parts. A ceramic media (grey in color) a plastic media (red color) and a final tumble in corn cob (white/brown). Any of these can get caught in tight crevices. Mostly it is the corn cob, small particles might appear as black, grey white or brown. Soaking or ultrasonic tends to make this stuff expand and lodge even tighter in crevices. I know it's a pain, but really the most effective way we have found to remove it is by picking it out. -G PS The Ganoskin website is a great metalworking resource!