Black Chromate Solved. Come in for wear solution.

[jpelosi2002]

I'm restoring an old Lionel locomotive with alot of zinc castings that have been blackened. I was having the same problems with the easy wearing off of the black finish. I spent ALL day looking for a olution and I beleive I have it licked. I was getting the parts to come out nice and satiny looking, but I was able to scrape the oxide off with my finger nail. After much trial and error I have found a proccess that works.

The blackener pickle was mixed using one part blackening solution, nine parts distilled water. As a side note; with all the testing and experimenting I did today, I've found that agitation of the pickle sloution using large bubbles really lights a fire under this stuffs' butt.

I used a wire wheel with my dremel to remove the old blackened finish.

I degreased with carburator cleaner in an aresol can

I etched the part for 1min. 30 seconds in a pickle of 5% battery acid, 95% distilled water.

I rinsed the part very well in cold tap water, making sure not to touch with my bare hands.

I heated the casted part till it was very hot (don't know the temp, sorry) with my heat gun. (it was steaming all the rinse water out)

I immersed the part in the blackening pickle for 4 hours. Yes, 4 hours. I also removed the part from its steel hanger while it was soaking for fear that the hanger would spoil the pickel over time.

After the 4 hours i removed the part from the pickle with the hanger. I rinsed in cold tap water very thoroughly.

At this point I'm touching the part with my bare hands.
You'll notice the part looks very lumpy from built up oxide on the part, and probably looks blue and purple in spots around internal corners and recesses. I used a soft nail brush to "polish" the part under running water. This evened out the finish and got rid of the purple/blue stains.

After i blew the part off with some compressed air, I gave it a nice coat of 3in1 oil applied directly on the part and using a paper towel, gave it a little buffing action as I went along.

The result is a nice smooth, charcoal color (as blackened zinc is supposed to be) that I had to use a carpentry nail to scratch through (on my test peice).

I hope this works out for anybody who's been having trouble with this kit.
Jim