Category Archives: Uncategorized

Quality of Water for Protection of high-pressure pumps and Surface Preparation

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 question was “What should 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 2015-10-29

EVALUATION OF 20,000 PSI WATER JETTING FOR SURFACE PREPARATION OF STEEL PRIOR TO COATING OR RECOATING

EVALUATION OF 20,000 PSI WATER JETTING FOR SURFACE PREPARATION OF STEEL PRIOR TO COATING OR RECOATING

This is the original white paper monograph which is the basis for removal of paint and coating system by high pressure waterjet cleaning HP-WJ.  Prepared by Lydia M. Frenzel; Dr. Robert De Angelis, and Dr. John B. Bates, 1983

At the time, 20,000 psi (140 mPa) was the upper limit on the cleaning equipment.  Click on the link to download the pdf paper.

frenzel deangelis bates 1983 White Paper