Questions for the surface cleaning gurus

Newbie Questions
1

I am experimenting on my concrete again. I do this because I won’t work on someone else’s place until I can make my own drive clean to my satisfaction.

I ran my surface cleaner (whisper wash classic) on the driveway before with just water, no chems, no pre or post treat, just to make sure everything was working and not leaking.

Today, I pre wet the concrete, applied SH at about 2%, waited a bit, ran surface cleaner. While running the surface cleaner perpendicular to line of sight (TY racer) I noticed no matter how slow I went, there seemed to be a line of dirt left behind. I was pushing forward, pulled it sideways, went backwards, same thing. So I went over a decent section, overlapping about 9’ inches, still happened. I went and throttled down the machine a hair just to see, still occurring. In some spots the machine seemed to float easily over the concrete, and in other spots it seemed to stop.

So I finished the drive, but didn’t like how the one section was turning out, it looked blackish (where the cars park at). I then went and got a degreaser, watered it down, applied, then ran the surface cleaner over it again. I then went and rinsed the whole drive down and post treated with about a 2-3% mix in a pump up (what a PITA that was). I am waiting until tomorrow morning to take a pic so that the post treating has time to work.

THe section that looked darker was poured a year before the last section, I can still see the broom finish in the concrete, but am concerned that th esurface cleaner might have removed some of the cream. THe only other thing I can think of is that the asphalt (which is next to the concrete) was sealed last year and maybe there was some runoff over the winter darkeneing the concrete. I doubt it though, because this is the second time I sealed that asphalt with the same sealer, and it didn’t do it before.

Any thoughts or feedback would be appreciated.

8gpm unit with only cold water used. 12.5 SH used, but diluted with water.

Edit: side note - the non marking hose I got from BCE leaves blue marks all over black asphalt.

2

Do you just mean a line of dirt that can be rinsed away? If so, that’s normal. You might mean there was striping that wouldn’t come clean. When taking cream off the water will be clouded or almost milky in color. If you didn’t see that you’re fine. Some concrete is just darker than others. It’ll be easier to comment once you post the pictures.

Many have complained about the blue hoses and not actually being non marking. It has been talked about on here before. Most stick to grey because the blue will leave marks on concrete or other obstacles it gets pulled over.

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3

What he said^

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4

Man, I still get stripes no matter what I do. I’ve just come to accept it and do my best. Pre-treat, wash, post treat.

Someone mentioned the push-pull method which does help but man is it time consuming.

I feel a rotary surface cleaner just isn’t the best method. There’s too much cleaning going on around the skirt area. I suspect a roller style with multiple nozzles would be more consistent.

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5

Grey is the only true non-marking color

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6

I told you before, buy a 4 tip spray bar and screw in appropriate nozzles, you widen up the cleaning area around the skirt and clean more on every pass, eliminating almost all striping. It’s not a conspiracy theory, it’s 10 year old problem solving.

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7

Yup, and I’ll tell you a 5.5 can’t be used with a 4 nozzle.

8

I used a friends one 2 Thursday’s ago while calling him in for some man power after getting a huge parking lot cleaning job. They absolutely work on a 20 inch with a 3500 5.5 pump with the correct nozzles just like they work on my 8. Vendors don’t use these 8 hours a day, me and you have the same end goal with concrete, take my word for it.

9

I use four nozzle WW with hot water, I don’t post treat. 200 plus degree hot water does an amazing job quickly too.

10

Any idea what nozzles were on there? I was told in no uncertain terms not to use a 4 nozzle with my machine, so now I’m starting to wonder.

I did a nozzle calculator and to achieve 3000psi I would have to use 1.8 orifice nozzles.:flushed:

I’m currently using 2503’s on my 2 nozzle bar.

11

I was too busy to nerd out on surface cleaners and ask at the job, from memory on the gauge it was about 2200-2300 psi. I had laid pre treat before he arrived. It cleaned great.

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12

Hey might as well try it, $78 For the bar plus nozzles. I’ll have to install a filter of some sort though, they told me at the store the little holes will get clogged easily.

13

Yes give it a go and play with the nozzles. Every machines different with wear and tear, I personally will never clean concrete again with 2 nozzle bar.

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14

well, it looks like it took a very slight bit of the cream off. Don’t get it, called the company and the vendor said that those tips should be fine for my rig. FN BS. I wanted to put two more nozzles in it, currently using two out of four (thats how they ship them), but I thought, use it before you mess something up and ruin the concrete.

I never saw white in the water, maybe too much salt, dirt, ash, etc from winter roads. THe first time I ran it, so much crap was coming off it was like brown/black water. I didn’t expect glistening white concrete, it doesn’t work that way in the north if your plowing it with equipment.

I guess it is better I messed up here instead of a customers. I can just re-portland it, but I have another piece (not pictured) in front of this one that is spawling and I need to fix it. MOre money down the crapper, this is getting expensive.

Here is the pic.

IMG_1913
IMG_19133024×4032 2.47 MB

15

That black looks like algae or mildew. Pour a little 12.5% on a small area and see if it disappears. If it does then spray like 2%-4% on the whole thing. It should look fine when you’re done.

16

It’s not, it was pre and post treated with SH. It also had a degreaser on it. The discoloration I believe is where the surface cleaner tooik about a 1/16th of the cream off. It had a broomed finish and in the grooves of the broom finish you can see where there is not cream. I know, I broomed about half of it. Funny though, the top part of the pic is the most recent pour and one of the smaller pours at about 9 yards, and it looks better. I would have to get a close up for you to see the damage. Maybe after I till my garden and re-winterize my rig I’ll take a pic. 71 yesterday, and now 32 tonight with a low of about 28-29 tomorrow.

I can’t catch a break here, maybe I should have stuck with painting. Between corona, the government shutting down work, and the government offices being closed coupled with the weather…just so glad I paid for everything in cash. I can’t imagine what it would be like if I took out a loan this year.

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17

What percent did you pre and post with? How long ago was the concrete poured?

18

I don’t know the percentage I put pretty fresh 12.5 in a 2 gallon pump up. The pre was about 2 the post was about 3.

I deferred my costs for the concrete for several years by pouring roughly 10-12 yards every summer or two, so that piece is maybe 4-6 years old. The piece in the pick at the top is my best pour i’ve done, it has a triple angle in it for water run off (angled from asphalt to grass, and angled front to back and back to front to keep the water away from the front of the drive). I hire masons to help me on pour day (and to trowel it because I suck at trowling) . THe whole thing has rebar twist tied, with rebar connecting the sections together… I did the drains myself and on pour day it went pretty smooth except they wanted more concrete at the end so I had to cut out some asphalt to make it work that day (hence the little cut out section).

The trick to keeping concrete off asphalt is ducktape and 10 mil plastic. Otherwise splatter form the chute or portland on boots marks it all up. IF you ever install drains make sure to duct tape or film cover the grates before the pour, I did and was so glad when screeding and floating that I did.

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19

I’ve only poured a couple slabs and have had help. The hand troweling is definitely a work of art and a skill I don’t have.

I’d still pour do a small test with straight 12.5% just to see. It won’t hurt anything. When using a pump up you don’t always have the capability of saturating the concrete enough especially when doing a large area. I just don’t see what else that black could be other than organics. If the black was just in certain areas like where vehicle’s tires hit it I could see it. You said you never had the black in previous years. Last spring was a wet one or at least in my area. I had customers say they’ve lived in their house for 20 years and never had the organic growth as what they had last year. I know pictures don’t really show the finer details though so maybe you are dealing with something else. I’d still do a good soaking with 12.5% in a small square foot spot. At the very least just to rule out that you might not have saturated it enough with the pump up. That’s especially easy to do on concrete when the sun is out.

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20

I thought the concrete was wet in the pic but if that is dry and after a post treat, dang you took some cream off alright! Sadly, no fixing that unless you have it resurfaced. When i clean new construction concrete, i use a pressure gauge at the handle of my surface cleaner, and twist the unloader on the pressure washer until i am only getting about 1000 - 1200 psi with the trigger pulled on the surface cleaner. I pre and post treat. Just know this will make your surface cleaner feel really heavy so its easier to pull the surface cleaner as you move perpendicular to the line of sight then to push or move side to side.

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