Finishing metals with vibratory tumbler

[rx7carl]

Hi all. I'm really needing some advice here. First the background info. I rebuild and modify carbs as a sideline. The linkages are cad plated steel and after 20 years need refinishing as many of the ones I get are rusted. I have the caswell zinc plating kit which does a great job of plating the linkages. Heres my dilemas. I have tried both alum oxide, and glass bead blasting before plating. The satin finish ends up a very dull gray after plating (surface too coarse). I have a vibratory tumbler, in which I tried alum oxide with the same results. I cant be spending the time to hand finish each piece of linkage before and/or after plating. I'm shooting for a nice silvery zinc finish, doesnt have to be chrome looking. My hope is to media blast the linkages en masse, then drop them into the tumbler, then plate and be done. Or tumble them after plating, doesnt matter. I really need to achieve this finish in a single automated step. Can someone reccomend a media to use in the tumbler that will work well for this application?

you can give walnut shell a try ...

[rx7carl]

How long will that take in the tumbler? Im assuming this would be an after plating operation?

i am not sure about that one ... i use it in my blasting cab.. this is the one that stumped me ... sorry ...

[rx7carl]

No problem, thanks for the reply.

[Itu]

I do not know much about the diferent types of finishes, but if it is a soft metal, corn cobs will work well in a tumbler to produce a nice smooth finish.

[red911]

I have two tumblers. The first is filled with green plastic prymids and a little water. Then when I want a polished finish (not for the carb bodies, but for the rods) I use the walnut agitation.