This is probably a dumb question, but will CLR work to clean the calcification(sp?) off the bottom of the boat? Is CLR going to damage the paint or fiberglass? Would diluting it to a milder mixture help? I mean you can use it on showers and tubs which are primarily fiberlglass as well. Any other easy suggestions to getting tough water stains off the hull are welcome.
I've used star brite hull cleaner, it's primary ingredient is oxcillic acid. The vapors will make you cough if you get downwind, lol. But hte stuff works great. Just spray, let sit for a few minutes, then wipe off and spray with fresh water.
Any acid will work. Muratic acid (dilute hydrochloric) is cheap and works very well. It is corrosive and hazardous, like any acid to your skin and the chlorine released while working is hard on your lungs. Operate upwind and use a long handled sprayer (all plastic, no metal). vinegar (dilute acetic acid) will also work, but takes a lot more work since it is not as powerful (pH of 4 vs 1 or 2).