Craft · 6 pages · 12 min
How a patina is chemistry on the surface
A patina is a skin of corrosion compounds grown from the metal, air, and moisture.
When the purchase is complete, return to the original window. It will refresh.
From the opening
A patina is a layer of chemical compounds grown on a metal surface when that metal reacts with air, water, and whatever salts or gases are present. On copper and bronze the layer is made of oxides and other copper salts, not of paint brushed on from a can. The opening covers metal atoms become surface salts, air and moisture feed the film, and a tight film can slow attack.
The rest of the brief — the later sections and the reading notes — opens after Stripe confirms payment.
Inside
- Metal atoms become surface salts
- Air and moisture feed the film
- A tight film can slow attack
- Chloride pockets can still pit
- Where the idea stops applying
- A distinction worth keeping
Sources
- Copper corrosion films and patina
- Bronze surface mineral crusts