50ml / 95g Pour a little Powertex out on your piece, mix in the Rust Powder with palette knife and spread.
Make a paste with Powertex as described above with 3D Sand, Rust Powder, a dash of vinegar and a dash of water and apply it with a palette knife.
Or use Powertex Easy Structure mixed with Powertex and some Rust Powder. Sprinkle some extra powder where a darker effect is desired and press in. Mix a little vinegar with water in a spray bottle (max. 50% vinegar).
Spray the peice a number of times, there should be a pool of water on it. Let it dry for at least 24 hours.
If you would like more rust effect spray again with more water and vinegar, leave to completely dry. If desired you can add more Powertex, pigments or acrylic paint.
Once oxidation is complete rusting will stop.

Quote product reference: P06179