Clutch basket

Hi.

The clutch baskets appear to have been dull copper plated much the same as the road bikes' clutch baskets- not for appearances- probably just to stop them rusting. The finish isn't very thick and may have been achieved by simply dipping them in an acidified solution of copper sulphate.

225 g/L Copper Sulphate - from chemist or garden centre.

50 g/L Sulphuric Acid - battery acid.

0.5g/L Hydrochloric Acid - chemist or builders merchants.

A few words of caution - Copper Sulphate (sometime used as moss killer) is poisonous and harmful to the environment, Sulphuric Acid is very corrosive, if concentrated, it reacts violently with water boiling instantaneously - best use already diluted battery acid (see below). Hydrochloric Acid, if concentrated, gives off corrosive fumes and is, of course, corrosive itself. ALWAYS ADD ACID TO WATER - not the other way around.

Apart from the above, it's quite easy to do, just make sure everything is scrupiously clean. The Sulphuric Acid concentration requiredis roughly the equivalent of a 1 in 100 dilution ofstandard battery acid (552g/l at 30% v/v)and you might be able to get away without the Hydrochloric Acid. I've nevertried it ona clutch basket but have done it successfully with mild steel components. Don't leave the object in too long or you'll end up with a flaky, powdery finish- a bit of trial and error is involved.

Regards,

Ian.

G'day Ian,

Any other details? "Too Long" is, ahem, a little ambiguous, maybe a time ( minutes / seconds) would be helpful"

If parts are blasted (30 micron glass beads) and then suitably cleaned & degreased and dipped in a weak solution of HCl (10:1) to make sure there is no rust, what sort of deposition rate are we dealing with?

I take it this could be termed as "Electroless Copper Plating?"

Thanks Steve

Yeah, sorry.

The copper 'flashes' over as soon as the item's dipped. I used this method to give a bit of extra corrosion resistance to medium sized cycle parts (it worked well). It only takes a few minutes but I'm afraid it's so long since I did it I can't remember exactly. I'm afraid anyone attempting this will have to experiment - like I had to. And, yes, this is a purely chemical reaction - no electrodes involved.

Regards,

Ian.