Did u know this process?

I would've thought iron and water in a stagnant environment could produce that sort of corrosion in aluminium...

I think you missed the point. These appear to be deliberate etchings to create a surface texture.

Photo-resist may be applied to create whatever pattern you like.

Etchants for aluminum can be: mild acids, strong bases, and ferric chloride, among others (yes, ferric chloride... I know it's "for copper", but it works nicely on aluminum).

The concentration of the etchant and agitation must be adjusted to minimize undercutting of the pattern.

LLoyd

Get some scrap and some chemistry and experiment.

A "Jackson Pollock" splatter painting with bitumen paint, then etched in warm caustic soda for a short time, will give a similar effect.

Much depends on the initial condition of the aluminium, alloy and surface finish (especially anodising). Don't expect repeatable results between different sheets.

hi,Lloyd, did u know how to clean the brownish after etched by ferric chloride. yup,if no other chemical can direct make this result, i also think probably is by photo-resist process! but it seem very naturally.

thanks

lee

Lloyd E. Sp> >I would've thought iron and water in a stagnant environment could

I learned that the hard way at 14, when I went to etchmy first PC board in an aluminum TV-Dinner tray. Mom was not pleased.. :)

Jon