For 30 years, I have received questions about the quality of water that should be used for removal of coatings. How much dissolved material or minerals gets left on the surface? Just recently after an hour long webinar to 200 people, the questions was “What shoul the quality of the water be?”
Among the first comments which I received on the WJ standards documents came from Singapore: The complaint was that we didn’t advocate cleaning with brackish or filtered seawater.” Just recently in 2015, a Sherwin Williams representative talked about the methodology in Brazil where WJ was being used for primary surface preparation, and not just potable water. However, I also received call in the mid 190’s where contractors said that they could tell the difference of quality of water between municipality sources. The better the quality of water, the better the removal, and the less flash rust.
As a task group leader for NACE and SSPC, the task groups finally defined surface preparation water. Surface Preparation water is water of sufficient purity and quality that it does not prevent the surface being cleaned from achieving the WJ-1 degree of surface cleanliness or nonvisible contaminant criteria when contained in the procurement documents. SP water should not contain sediments or other impurities that are destructive to the proper functioning of the cleaning equipment.
The following is a monograph on
The Quality of Water to be used in Surface Preparation and to Protect the Pumps.
Quality of Water 2015-12-14