Found out my finish water was causing blotchy spots - took me 2 months to figure it out

Been fighting these weird light spots on my last 3 driveways in Phoenix. Thought it was my mix or maybe bad batch of sealer. Talked to an old timer at the supply yard Tuesday and he asked what water I was using for the final wet finish. Turns out our city water here has high mineral content that reacts with the cream. Switched to a bucket of distilled water for the last pass and the difference was NIGHT and day. Has anyone else run into water chemistry messing with their finish like this?

2 comments

2 Comments

ray_webb65h ago

hold up i gotta push back on this a little. been doing flatwork for 12 years now and never once worried about my tap water. phoenix water is hard yeah but so is a lot of stuff we deal with daily. you think every crew in arizona is running around with distilled water buckets? come on. if your cream is that sensitive to a little mineral content then maybe the issue is your mix design or how fast you're working the surface. i've seen guys blame everything from humidity to the phase of the moon when really they just got sloppy with their timing or didn't cure right. not saying water chemistry can't matter but it's way down the list of things i'd check first. you swap to distilled and see improvement? great. but that could also just be placebo or the fact you finally paid attention to your finish pass because you were focused on the water.

derek9396h ago

Yeah that "bucket of distilled water" part really jumped out at me. Something else to think about - if you're mixing your own batch and using tap water for that too, the minerals could be throwing off your hydration and causing issues way before you even get to the finish pass.