Water and/or Oil Spots on glass bead and anodize 6061

[gking86]

We are running a large batch of repeat parts that get a flat black anodize on them. The parts end up in a bucket of soapy water when they come out of the machine, get tumbled in soapy water with ceramic media, dried with compressed air and then a fine glass bead. For some reason, we are now getting water or oil spots on the parts that we have not in the past. I'm thinking that we should switch to one of the tumbling fluids out there since dawn or palmolive don't seem to be cutting it.

Could be a water hardness thing too, checking to see how deionized water from the EDM does with preventing the spots now.

 

[kustomizer]

We use a tablespoon of liquid tide in the ceramic media, though we have seen things like you describe from material that was not made correctly and ended up with oxidation in the metal and the oxidation won't anodize

We always use hot, hot water in the tumblers and rinse water

 

[greif1]

How clean is the compressed air? A little oil in the air shows up a lot!