copper plating mystery

Flyingwing12

I had a solution of copper sulfate in (vinegar) and noticed that when I wire brushed certain metals, the copper made a beautiful arrangement on the work piece, often a perfect semi-gloss. The copper is also seemingly bonded to the metal ( can't wipe it off).

However, when I use conventional electroplating with the solution, the copper just barely hangs on the surface of the work. And with " dirty " copper as the anode, the result is very poor.

So why does this happen? I thought it was the wire wheel depositing a huge positive charge on the work ( which is a pair of pliers with insulated handles. ;) ).

Very interesting indeed.

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Simon Bridge

Wire brushing also dramatically changes the surface characteristics doesn't it?
Though, to me, your photo just looks rusty.

NascentOxygen

Interesting. This might be better placed in the Chemistry subforum, being quite appropriate for industrial chemists.

MATLABdude

I don't have a whole lot of experience with electroplating, but as Simon alludes to, electroplating is highly sensitive to surface preparation. When you wire brush, you're probably removing surface oxide along with any protective coating. Applying a degreaser (and scrubbing) also goes a long way towards removing oils, grease, and grime (which also 'mask' the surface, preventing deposition).

Still, if you hit the "Report" button, you can summon a moderator and get them to move your post over to Chemistry.