Removing zinc plating / passivation

[Error404]

Is there a way to chemically remove zinc passivation or plating? I have some delicate parts i wanted to strip the coating off to weld them, but i didn't want to damage them with abrasvies or blasting. Any pointers?

Cheers
Alex

[AndyP]

Soak them in vinegar

[Error404]

Thanks mate. Will ordinary household stuff do it?

[AndyP]

Yes, I bought 20ltrs from a cash and carry and had it in a bit tub in the garage, strips rust off a treat. This is how I discovered it strips zinc off, leave it overnight and give it a rub with a scotch pad.

I think the electrolysys / battery charger method will strip it too.

[Error404]

cool, I'll head out tomorrow and get some vinegar. Thanks Andy

[4WheelDrifter]

Or brown sauce, if you need the removal substance to be more clingy or localised.

[AndyP]

Or brown sauce, if you need the removal substance to be more clingy or localised.

Really??!!

[Error404]

good tip
I know you could use HP sauce to polish metal

[AndyP]

Just re-read your original post and as the parts are delicate I'd probably not leave them overnight, vinegar is suprisingly potent stuff! Do it during the day when you can check them every few hours.

[4WheelDrifter]

It's an old plumbers trick. Coat an old copper/brass fitting in brown sauce, then wipe off later for that 'new part' look.

Brown sauce is mostly water and vinegar.

[Error404]

cool - it's not heavily plated so i'll check it every hour or so

[4WheelDrifter]

I must apologise. When I said plumber, I meant heating engineer.
I don't want to upset them, and imply they have lead working skills that they don't.

[Error404]

[benntenn67]

Phosphoric acid - As used in Coke & Pepsi cola