I have a 40 year old shotcrete pool, about 20x40 in good condition. It has one coat minimum of rubber based paint and a coat of acrylic, put on 3-4 years ago. The acrylic is badly peeling off. I probably should sandblast but I want to avoid the expense. One paint manufacturer has suggested that if I power wash with at least 3500 PSI I can get the acrylic off and repaint with a synthetic rubber paint, I would need to get the acrylic off 100%. Any opinions on whether this will work? .