I recently acquired a number of Central Valley T-39 streamliner trucks (HO), which are constructed of zinc alloy (Zamac) die castings, and are unpainted. Since most of these will need to be black in color, I was thinking of chemically blackening the castings. This seemed like a good idea since I would not have to disassemble the trucks, or mask the wheels, before spray painting, and it wouldn’t obscure the fine detail. I’ve read about Blacken-It on another forum. That product requires dipping the items- which wouldn’t work well for the trucks. Blacken-It is also reported to produce more of a brown color on castings. Can anyone suggest a better product, or procedure? Thanks- Richard
The only other product that blackens I know of is Neolube, which is only graphite supended in alcohol, I think. It tends to rub off, and doesn’t blacken as thoroughly as factory blackening does, since it’s more of a graphite gray. I’ve tried Blacken-It as well, and it also doesn’t blacken thoroughly. The coverage can be spotty, and it’s also slightly corrosive, so it’s not a good idea to leave white metal parts in too long.
I’d like to know what process manufacturers use to blacken metal in production.
Black Oxide is the industrial process and it ain’t cheap. Blacken It works, but IS a bit spotty.
A couple alternatives.
http://www.victornet.com/productpages/toolblack1.html
http://www.precisionbrand.com/ProductsCatalog/PBPCategoryDetails.aspx?Catid=485
I used the first one YEARS ago on steel and it worked very well. Very black. The key is using the whole 3 step chemical process. degreaser/blacken chem/sealer.
That stuff looks interesting, but it says it works for ferrous metals, which would rule out Zamac. Did you use it on something other than steel?