Rusted, or tarnished? Do you know what the underlying metal is? Usually it's brass, and the gold plating is then applied over silver plating. At any rate, that's the way brass instrument mouthpieces are done; the gold is not applied directly over the brass. This doesn't answer your question, I know, but I'm leaving that to people who really know what they're talking about!
Post by wmbuchanan on Sept 14, 2008 22:00:46 GMT -5
John was asking for me.
The part is the hand crank which is steel that has been either painted or plated in gold.
I was thinking of removing the rust, painting this with a good primer and then with a very good gold paint. The paint of course does not look as bright as the gold on the handle. Does anybody have recommendations as to what I should do to make this look as close to new as possible?
If you're thinking about sanding the handle down & painting it, it might be worth trying Phosphoric acid first. I haven't tried this on gold plating, but have used it many time on nickel plating. I threw my empty bottle away a couple days ago, but it works by converting the oxides in the rust into something else(cant remember the correct word now). It can either be bushed on & left to dry, and the rust present is converted back to metal, or you can soak the metal, and it removes the rust completely. Like I said, I haven't used it on gold, but I honestly think it won't harm the plating due to no oxides being present. Below is a handle I did the other night. As you can see, it cleaned up well, though there really wasn't much plating left to be left behind. The other 2 px are of a speed control. It left plenty of plating because the acid won't touch it. It will however remove the plating where rust has formed underneath the plating, but any plating that is sound is left untouched. It is sold over here in hardware & auto shops as rust converter, and is just a liquid. Phosphoric acid is listed as the active ingredient, & is about 34% by volume. When it's applied & left to dry, you run over it with a damp cloth to remove any excess & needs to be sealed. If you soak it to completely remove the oxidisation, you then wash it under running water to remove the acid completely. It's still best to seal the metal with wax or clear lacquer to prevent future oxidisation.
Post by wmbuchanan on Sept 15, 2008 1:18:23 GMT -5
Thanks, and the photos really helps to show what is possible. I fear that the rust is under most of the gold plate so if I use this I will loose the gold that is currently still on the arm. But if I let it go I will loose the arm as a useful part of the player. I have a rust converter that I believe is acid based, it will turn the area black and it also seals the area, I'll check this out in the morning. The instructions tell you to remove all loose rust first because it will seal metal. It comes in a spray and is made for cars and such. Good stuff I've used it on my truck panel where I was not able to reach last year (this was before my injuries decided to put me to bed for the past year). Thanks again for the photos and for the information.