SO, top of photo is where these folks park their cars (the ones not in the garage) I pretreated the top of the photo with 1% and car wash/wax (yeah, the guy told me that it leaves a shine on the vinyl siding post washing, but it doesn’t).
Still looked pretty grungy, so took @Racer 's advice and popst treated with a 3% solution:
Observations: Pretreat BIG benefit, and posttreatment absolutely necessary where stains still harass.
The more porous the surface, the more likely the striping.
When it’s wet enough, striping may not be an issue (see above)
No matter what you do, some crap will NEVER come out.
Conclusions: Henceforth, I will ALWAYS prewet/pretreat with mild SH/strong surfactant and post-treat where
In reference to @John_Martinez and @squidskc, my game went WAY UP when I switched out
my nozzles, but more importantly (and what nobody talks about) lining up the nozzles so the
lines are in line with the bar!
OH, I have one more observation: So I blow out the second General Pump Quick Release (threw the 1st one in the trash) where my ball valve connects to the XJet/SC. Switch out to the Bob stainless that I discovered on my doorstep this morning at 6:30, and curious about why those brass QR’s blew out on me when I notice an o ring on the concrete that I’m cleaning. HMM, could there be a relationship? Then I remembered a post about using dental picks, and somebody posting (was it you Brodie?) that those picks were the only thing bought without shame at Harbor Freight. SO, this observation relates to my ball valve: that sucker is hell on QR fittings, and I need more o rings and a set of picks.
Any comments from the seasoned pros?
BTW, if the weather cooperates tomorrow, I will be back there to do the walkways in the back. I was too tired to unload/load the PW after a full 8 hours today, and place is so big that can’t reach the back with 200’ of hose). Will get the after pics of the entire circular drive then.