I want to do some gold plating, specifically on aluminium; iPhone 5 case is made of this. But, I have read that gold plating aluminium isn't simple as cleaning it and going straight into gold plating.
I think I read somewhere that process is something like: Clean it; put it in some chemical called "Zincate", or something along those lines; then a nickel coating; next copper; and then the final gold plating. Is this correct?
Also, what methods would be best for a cosmetic alteration like this: Brush and/or Tank?
I was thinking definitely tank for the final gold layer, and most probably for everything else. But, I don't know enough about to the processes to know if brush plating it would suit any of it better.
Finally, I assume the more times you use the metal solution the weaker it gets as it has less gold in it.So, what do I do about this? Do I just buy more metal solution or is there a way to replenish the metal solution to make it more concentrated, maybe from a sort of solution or with scrap metal itself (if that's how it works).
Any help on this subject will be much appreciated, and any additional info would be great.