gold plating on brass

[jomida]

I'm new to this stuff, and I have a bit of a dilema. I am working on a piece that was originally gold plated. When I started, it was heavily tarnished. Starting with black, I used various compounds and wheels to clean it up. At this point, I had a pretty nice looking piece of brass. To restore the original finish, it must now be gold plated. I am using Fastgold.

I plated the piece with the Fastgold. This was surprisingly simple. I then polished with blue compound on cotton flannel wheel. Excellent finish. However, my untrained eye cannot distinguish whether I am looking at a gold plate finish, or the same nice brass finish I had before I started plating. It is possible that my plating process was flawed, or that I took the new gold off when polishing. How would I know?

For this piece to be 'as original', it must be gold plated, even though the brass finish is rather nice. Is there some kind of simple test I can do to determine the finish is in fact gold?

[mcaswell]

Gold plating should really be done over a nickel plate on brass. Otherwise the brass will tarnish and turn green through the gold.
So you'll easily be able to see where you put the gold when going over nickel. A fairly thin layer of nickel is sufficient.

[jomida]

The plating manual states that Fastgold "will plate over nickel, sterling gold, gold, rhodium, copper, brass, and bronze". Is this not correct? I understand distinguishing the color is a bit of an issue, but tarnishing and turning green was not part of the deal.

[mcaswell]

It depends on the application. Fastgold will plate onto brass, and in many situations it will be fine. In more aggresive environments, it may tarnish. Remember gold goes on at 1-2 millionths of an inch thick. Thats fairly easy to rub off, especially on jewelry which is continually being rubbed.

[jomida]

Got it, thanks.

OK. If I start with good brass, I would want to brush plate with nickel (nickel wand), then brush with Fastgold (SS wand).

I know that the key to a good finish with gold plate is good surface preparation (polishing, mostly). If I am going to plate the brass with nickel before I plate with gold, is the surface preparation equally important with both layers?

Assuming the brass is good to begin (no pitting, etc), I would finish up the brass with white compound on a loose wheel, finish up the nickel with red on cotton, and finish up the gold with red on cotton. Is that right?

[mcaswell]

Sounds like you're on the right track.