IMPORTANT INFORMATION
Unlike sand or other media blasting that needs to be primed immediately post blast to stop rust forming, in most cases your sodablasted piece will be returned to you in the bare metal state. Any imperfections, metal creases or cracks hidden by top coats will be obvious and allows for remedial work to be done prior to painting.
NATURAL RUST INHIBITOR
As long as the baking soda residue is on a ferrous metal surface, rust will not form. For rust to form, free moisture and an acidic condition must exist. In most cases, free moisture combines with carbon dioxide in the atmosphere to form carbonic acid. This acid releases a free metal (ferrous) ion, which combines with oxygen (oxidizes) to form rust. Baking soda buffers the acids, prevents the release of free metal ions and prevents rust.
PRE-PAINT
While your sodablasted piece can be left unpainted for a number of weeks whilst stored inside, surface soda residue needs to be removed before applying any coatings. A thorough water blast should be sufficient to remove the protective soda. Paint or priming should be applied as soon as possible after washing, ensuring that you adhere to manufacturer's pre-paint instructions.