The intention of this field trial was to reduce residual dust contamination and improve surface cleanliness after blasting with copper slag.
Using ‘copper slag’ to blast clean a test panel the blaster intentionally adopted a technique which would maximise both blast media particle embedment and residual dust contamination.
Using the method ‘Elcometer 142 Dust Assessment in Accordance with ISO 8502-3’ we tested for residual dust contamination.
As expected, the results were terrible:
The blasted surface was visually assessed as achieving Commercial Blast (SA 2, NACE 3/ SSPC-SP 6), as there was a great deal of staining evident. This is likely because the Copper Slag was very coarse and the particles were unable to clean out the crevices, leaving a high level of staining.
The test panel was then high pressure washed at 3000psi with 1% Corr-Ze™100 additive.
The surface cleanliness standard improved, and was visually assessed as achieving Near White Metal (SA 2-1/2, NACE 2/ SSPC-SP 10), as there was still staining evident, but better than before.
The big difference was that the water blasting almost completely eliminated all residual dust contamination:
As a final test, Corr-Ze™200 was applied to a small zone at the bottom left of the test panel to see if the staining could be removed.
Corr-Ze™200 did in fact remove all the residual staining, and was visually assessed as achieving White Metal Blast (SA 3, NACE 1/ SSPC-SP 5).