Take this from a professional blaster in the ship painting business: If you want to blast with water use a product like "Rust Lick" in the water. It inhibits the rust formation and you can paint right over it (or at least they do @work....) You'll need a 55 gallon drum to mix your water and rust lick in; draw the water from the drum into the pressure washer...or get a collar for your blast nozzle that will feed the water (from the drum or your faucet with a small hose adding the rust lick) into the media stream.
To All: When blasting wear a respirator that has a HEPA filter. The resulting dust doesn't have ANYTHING in it that will enhance your body's performance (or brain performance) in ANY WAY; in other words there is NOTHING in the residue that you would want in your body ok? I use a portable garage tent available from Costco or sportsmansguide.com. I get a huge tarp from Harbor Freight and use it as a floor covering over the CDX I lay on the ground under the tent. I fold the floor tarp up over the sides and ends of the tend to contain the dust. When I'm finished and wearing my respirator I SLOWLY sweep up the residue with a hand broom and put it all in bags and put it in the trash, as it's dry paint and metal it's not considered hazardous in my state but check your local laws BEFORE blasting. CONTAIN the dust, your neighbors don't want it either.
