Washing with Holdtight 102 after abrasive blasting dilutes and carries soluble salts, like chlorides, sulfates, and nitrates, away from the surface. When left on the surface these soluble salts act like little sponges, and they pull moisture from the air onto the steel surface.
Prior to coating, this results in early flash rusting, which will require the surface to be re-blasted. When moisture is in contact with contaminated steel, the moisture mixes with the contaminants to form a solution which is a very good conductor of electricity. Corrosion is an electro-chemical process, which means that a chemical change is taking place and rust is formed through an electrical process. Without an electrical process, the corrosion will not occur. The contamination provides an excellent conduit for the corrosion cell to complete its circuit on the steel, resulting in corrosion.
Now, did you know that distilled water will not conduct electricity? That’s because it does not contain contaminants to provide an electrical conduit for the transfer of electrons. For this reason, a completely clean steel surface will not provide an efficient transfer of electrons through an electrolyte and corrosion will be prevented or delayed.
After contaminated steel is coated, early coatings failure by corrosion can still occur because the salts (chlorides, sulfates, and nitrates) can pull moisture right through the coating. This can result in a corrosion cell being formed on the steel surface and out of sight at first. For this reason, the industrial coatings industry is extremely focused on surface cleanliness and salts removal prior to application of coatings. This is especially true for tank linings, which are in constant contact with liquids in corrosive environments. However, all coatings will experience longer life when applied to a clean surface.
At Strand’s Industrial Coatings, we can help you find the right salts remover and equipment to get the job done right the first time. Contact our team of experts to learn more about using Holdtight 102 for your application.