Not motoring but.oh well.

attitudedesignz, Sep 24, 11:25pm
I know some here will be into metalworking and such so thought i'd ask here first.

How do i go about getting copper to look like this?

Not the "patina" (I hate that word, so overused) but the "eaten" away edges.
I'm assuming it'd be done with an acid of some sort but no amount of 'googling' helps.

https://trademe.tmcdn.co.nz/photoserver/full/414398792.jpg

mrfxit, Sep 24, 11:28pm
I would suspect an acid spray on & wash off when the desired effect is just about done.

attitudedesignz, Sep 24, 11:29pm
Yep, but what acid is the thing i'm chasing.

brapbrap8, Sep 24, 11:34pm
Google reckons that Nitric acid is the only thing to dissolve copper.

skin1235, Sep 24, 11:35pm
sulphuric?, could try a strip and see what the time frame is
doing it with electrolisis via copper-sulphate, reverse the polarity and send the copper to say a steel bolt? may need say a wax splatter to achieve the holes though

mrfxit, Sep 24, 11:36pm
D'OH yea sorry, speed reading again
Nitric acid apparently
or if you are really brave
aqua regia

skin1235, Sep 24, 11:36pm
wondered about that as I typed in the above - although sulphuric and copper should create copper sulphate, hmmmm

mrfxit, Sep 24, 11:39pm

mm12345, Sep 24, 11:53pm
Nitric acid can be nasty stuff to deal with.
An electronic store like Jaycar probably sells "etchant" for people making home-made "printed" circuit boards. Ammonium Persulphate or Ferric Chloride are possibilities. Here you go:
http://www.jaycar.co.nz/Service-Aids/PCB-Accessories/Solvents-%26-Other-Aids/Ammonium-Persulphate---400gm/p/NC4254

stevo2, May 9, 12:35pm
I cant help you with that look, but I had to age some old copper quickly on a job for a client and they happened to live next to the sea.
I dipped the nice shiny copper in the tide for a minute or two and within a few hours the colour changed to a deep red.
Not the look I was after so I had to clean it up with steel wool and leave it outside for a couple of days to get the weathered look.