Does anybody know of a chemical (or chemical process) that is able to etch away a tin/lead alloy (or a tin silver alloy) from copper without damaging the copper? I want to make a design on a copper sheet and was hoping to be able to cover the copper in tin and then etch the design back to the copper layer. The alternative process is cutting into the copper, filling with tin and then sanding everything flat again.
Well since tin is a lot softer than copper I would think you could etch it away with acid and when you can see the copper where the acid is, you simply pour on water to neutralize the acid.
you'll want to pour on an alkali solution not just water to neutralise it. The water will simply dilute it and you'll still have an acidic sol. Something like Sodium Bicarb (Baking Soda) will be ideal and it's readily available.
If I've understood it correctly... he wants to tin-plate some copper and etch a design into the tin, leaving the copper underneath untouched [or as untouched as possible]
In that case: do the tin plating, coat the whole thing in wax, draw the design in the wax, clean the bare areas with acetone, and immerse the whole thing in an acid. Neutralise the acid, and remove the remaining wax.
I just realized that the etching plan won't work after all. I just can't get the tin plating even enough for the entire thing to polish out properly afterwards. If I were to do thing I think electroplating would be my best bet, but that's a bit too complicated for a weekend project. Time to whip out my Dremel, then. Oh, and for those still wondering: I'm just making a new pick guard for my guitar. It's going to be polished copper with "chrome" edges and maybe a logo. Tin seems to polish well enough to look chrome in small quantities. (Actually it's closer to nickel in color, but the hardware on my guitar seems to be a light nickel color so I think it will work well enough.)
