Abrasives used for surface cleaning by blasting can be contaminated with soluble salts due to the origin or reuse of the blasting medium.
This contamination can be transferred to the blast cleaned surface and result in accelerated corrosion conditions and can also cause premature coating problems if this contamination is not removed before the coating is applied.
Testing the Elcometer 138 for corrosive soluble salt contamination according to ASTM D4940 method can be done quickly and easily.
A measured volume of abrasive is mixed with the same volume of water and agitated to allow the water-soluble salts to dissolve. The resulting slurry is allowed to settle and the filtered water can then be tested using a conductivity meter.