I'm a small time pressure washer - only do it part time as part of my other home improvement business. I have a 4/4k machine. I use X-Jet when I need chemicals, rather than downstreaming. I also have a Blue Clean 383SS for smaller jobs/less pressure, that can spray chemicals (through the pump). My surface cleaner is a General Pump Hammerhead.
My question regards chemicals on residential concrete driveways, sidewalks, and brick porches/steps. I haven't seen any chemicals that do better than simple water pressure by itself. I used to do work for another guy when I started. He didn't know much about pressure washing, but he always had me prespray the surface with bleach (hand pump tank). At the time I was only doing small areas, with the wand only. The bleach made absolutely no difference as far as I could see in getting the surface clean. Black concrete turned light and clean in the exact same way with bare wand or pretreated.
I've since read in this forum that some people use oxalic acid to brighten concrete surfaces. One guy said he had good results by post-treating - applying the OA solution after cleaning, and then just leaving it. I have some I use for deck neutralizing, so I tried it. One section directly next to another section that only got pressure. Exactly the same, no difference.
So, what am I missing here?
My question regards chemicals on residential concrete driveways, sidewalks, and brick porches/steps. I haven't seen any chemicals that do better than simple water pressure by itself. I used to do work for another guy when I started. He didn't know much about pressure washing, but he always had me prespray the surface with bleach (hand pump tank). At the time I was only doing small areas, with the wand only. The bleach made absolutely no difference as far as I could see in getting the surface clean. Black concrete turned light and clean in the exact same way with bare wand or pretreated.
I've since read in this forum that some people use oxalic acid to brighten concrete surfaces. One guy said he had good results by post-treating - applying the OA solution after cleaning, and then just leaving it. I have some I use for deck neutralizing, so I tried it. One section directly next to another section that only got pressure. Exactly the same, no difference.
So, what am I missing here?