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itswillist

My surface cleaners are leaving stripes ?

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Ok here are the specs: I have 2 pressure washing machines

1) 3500 PSI 4GPM

2) 3750 PSI 4GPM

And I have 2 of the same type of surface cleaners: 27" Northstar that came with the 1502 tips with it. I have been using these surface cleaners for a while now, and for some reason they both started leaving uneven cleaning patterns. They're not leaving the little twirly circles like they do when one of the nozzles are stopped up. No when I clean a long driveway everything looks great when there cleaning, but when it's finished you can look back and see long stripes that I have to go over and over to blend in with the concrete. I already bought new tips but they're still doing it .And these stripes occur weather I go fast or slow ... Any takers ??? As I'm very agrivated about having to clean things twice ... Any advice would be golden ...

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With a 4gpm you don't want to go any bigger than a 20" cleaner. Or else you have to walk incredibley slooooow. Are you using any chems? Using a good soap and chlorine if there is mold/mildew will also help. Following up with oxalic will brighten the concrete and it will look better once it dries. All these things combined will help.

The stripes are simply caused because you aren't getting the concrete as clean as it could be on the first swipe (too fast, no chems, etc). Then when you take another pass your overlapping a little and hitting part of the concrete again. So where you've cleaned the concrete twice is where the stripes occur. So the trick is to get all the concrete as clean as possible with the first swipe, then you'll have no stripes. That's why going slower, using better chems, and or using hot water helps.

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How many arms do you have on your cleaner? 3? If so you can drop to two arms. This will force you to have to slow down a little, but you will get overall better pressure per nozzel with 2 versus 1.

But alone with Barry, better chems will help emulsify the dirt and lift ir better. The best solution is to get more GPM...5.6 or more. And even better, hot water.

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I only have 2 arms on the cleaners. I would like more GPM and pressure, but the thing that gets me is the fact that they just started doing this, I used them the exact same way, same speed, and all with no problems. I put these new tips on them (the same as before) and now there leaving the stripes ... I don't know what the deal is. Like I said, they leave them even when I walk slower.

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I think Barry hit it with the overlaps being cleaner then.

Couple other things that could be going on. . .

Pressure washer not putting out GPM/Pressure that it was? If you have the SLIGHTLEST leak/drip on the pressure side this can drop you a couple hundred PSI. Orings in your quick connects can go bad and are cheap to replace. A connection could be lose. Something could need to be resealed with teflon tape.

Water supply is less than 4GPM and causing your washer to starve a little for water?

Pump has lots of miles on it and just not able to put out the pressure or GPM?

Unloader bad or backed off? I have seen people use the offloader to back the pressure down. (why not spend 6 bucks for the right nozzle and QC?) If your Off loader is backed off you will get less GPM and PSI.

The best way to test all of these is with a pressure gauge and flow meters. I know you can get pressure gauges and a flow meter to test water spigot output, I have both. Not sure where or if you could get a flow meter to test the GPM on the presure side.

But if you are getting cleaner stripes due to overlap, then the first pass is not cleaning like it should.

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Is the surface cleaner even. When I used to rent them, a couple times the arm on one side was bent from a weld repair so one nozzle was closer to the ground and then another time the tire was low on air on 1 side. Could be that or probably what the others have stated

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they're called racing stripes and the speed, gpm or how many arms the surface cleaner has, has nothing to do with it. It's simply where you are overlapping. Prespraying with a good chemical should solve it. It did for me.

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I'll keep playing with it and see. I just don't know what it could be, we're cleaning the same gas stations as before, same tips, same units, same speed, but now they're both doing it.. If it was only one, then it would be easier to determine.. but they both do it off both machines ... ?? maybe these new tips are the problem ?? Though they're the same ones as before, that's all I can come up with for now ...

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Here's some contrast...Maybe yer cleaning too good.. Increase nozzle angle or size in the surface cleaner, add hose, etc... if ya turn things down you'll sacrafice gpm though.

Two 2's give you a tot of size 4 and on a 4gpm that gives you 4kpsi. That be rather high. When you use that much on some newer slabs with questionable strength or finishing techniques of the concrete your asking for problems of swiping off the thin slurry coat. That is what these stripes may be rather than good old fashion dirt persay. Close up they may look etched but farther out they look like dirt or can hold and collect dirt at a much faster pace. Hence the opposite of normal can become true..where you see stripes is where you cleaned more..

Even a regularly serviced older slab that has been getting lower psi can show such stripes when all of a sudden higher pressure is used. The top few milimeters of surface usually has sun bleaching/chem bleaching/leached effects that is best left alone.

You could ask yourself did you do anything to system that gained you some power such as less hose, corrected a pump or unloader issue, etc.

If you goto 2.5 sizing you drop too low perhaps for your taste at about 2600psi. . Some nozzles of 2.25 size would be ideal giving you about 3100 or so, if you can find such that is.

ps- you using heat? Even though it wouldn't account for your sudden change it sure does make a big difference on dirt.

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Adjust the angles so that bar spins only as fast as needed to where you can't outwalk it. Anything more is wasted power..almost straight down is an option I am fond of.

Here's a little info..sorry but I don't have the pic of the angle handy.

Cleaner Times Magazine

An ailment that most contractors are familiar with is “zebra striping.” Tassone says, “Surface cleaning, for the most part, is a technique. You have to calibrate your speed with the machine that you’re using. If you’re on the slower scale of cleaning, you have to slow your cleaning motion or else you’ll end up with zebra striping. If you move too fast, you’ll end up with swirls on the surface. There are other factors that can cause cleaners to zebra stripe – especially if the nozzle tips are out of alignment. If the tips aren’t aligned properly on the bar and at the right angle, if the unit is spinning too fast or if you go too fast, you’ll zebra stripe.”

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Different machines, different surface cleaners, same problem. This means one thing.

Prespray your work area with a quality cleaner and the problem will go away. You need total saturation, not a quick pump up spray job.

The stripes come from the overlap as that spot gets cleaned twice. The other option is to walk real slow so that the surface can not get any cleaner when the ovelap occurs.

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Try spraying straight bleach mist or chlorine onto the wet drive as soon as you rinse. The streaks will disappear and the drive will look much brighter. Sometimes here in Florida the mold under oak trees is so thick that it gets deeper into the concrete and stains it so that pressurewashing alone wont get it all up. Even pre-spraying with a bleach solution prior to cleaning wont always work, but it certainly helps and I pre spray all my drives. Roof rigs are ideal to have in these cases since chlorine eats cheap pump ups, but a pump up is better than nothing.

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These are all great theories, I'll play with all of them and see what happens. With my type of machines you think I should stick with the 1502's or try 2502, 1503 maybe ?? I don't know if they make tips between 02's and 03's ????

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tips wear out pretty fast so start on the smaller side. I should replace mine more often. It keeps your pressure up. 15 vs 25?? I guess a faster spin would use a lesser degree tip.

You are 4 gpm so use 2 and not 3. If you are using really long hoses or your pump is worn a bit and doesnt produce the gpm at spec. you can go a bit smaller than 2. The scrubber will feel a lot stronger and will cut better. Maybe buy three or four sets and test them.

I am assuming you have a two tip setup on your scrubber.

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With my type of machines you think I should stick with the 1502's or try 2502, 1503 maybe ?? I don't know if they make tips between 02's and 03's ????

The bars are so close to the ground that their is not much difference between 15° and 25° on most units. I know they make 2.25 in 1/4 meg nozzles and am sure they have others inbetween as well.

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No more Stripes when surface cleaning!!! - Pressure Washing Institute

If anyone wants to read my reasons please feel free to click above.

Why click Ron? ..post away..

I'll help ya out :)

Ron says:

No more Stripes when surface cleaning!!!

Check tips

1. damaged orifice

2. debris stuck in tips

3. warn out tips

4. tips out of balance from hitting objects

Spray bar

1. angles are correct

2. bars are balanced and not bent

3. no damage to bars

Shaft & Rotary union

1. lubrication to shaft

2. lubrication to union if able

3. make sure union is tight and no play in the shaft

I have found that when you have check most of the above the number one problem is wear or damage orifice.

With your eye you turn your surface cleaner over and look at the tips, it seems your nozzles are spraying even. With your naked eye you cannot see that the orifice has been altered just enough to disburse a micro zero area that causes this what most call striping. It’s simply spraying a small area with greater pressure, that causes and uneven cleaning.

Yes over using chemical can cure it by using the chemical to help the less PSI area clean as good as the tiny area that is applying more PSI.

Doubling over the cleaning area is another cure for fixing the stripes. I’m here to tell you this is not necessary if your surface cleaner is running properly.

I tested many brands when surface cleaners where being invented. The factory sent them to me because phoenix is hot. The experience and things I learned working with the engineers who invented these machines was valuable.

The tips you should be using where originally invented for parts washers. Inside of a parts washer the debris and often the parts would strike the nozzle. Of course in parts washer’s not so critical if the orifice was damaged. Regardless they needed to get more wear out the tips. A parts washer tip has a protected area and the orifice is damage less.

I say this is not the only reason but the one many here and elsewhere do not understand.

It’s simply the number one reason and many false cures can fix it. It’s as simple as using the protected tips and changing them first when problem starts. (Unless it’s something more obvious of course)

ps- oh and btw..yes I have to concure with the idea of a proper fixing of problem instead of using more chem. That's just regressive and expensive if your already using heat.

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KEvin, Pressure Washing Institute - View Single Post - No more Stripes when surface cleaning!!!

Kevin,

It’s ok that you posted the info; please if I don’t share the text please don’t just take it. If tgs wants to kill the link they will.

I have reasons that info remains on *** like Beth has info she keeps here but shares with others from *** through links.

TGS and *** are friends, as well as PTS and most all other BBS.

Kevin, please do not take this post wrong.

*** is my preferred like TGS is yours or Beths. That is respected and your welcome to drive anyone here to access great info. I will respect that and never take your post and copy them to *** unless you ask me too.

For others, yes in the past I have taken content and now I just hyper link.

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John,

If your surface washer has a height adjustment raise the spray bar height. I did this years ago and it helped on one of my units that did the same thing. Also, I agree with most of the other comments so try them too.

Hope this helps,

Andy

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nice ron,

i noticed some foam on the concrete. did you use any chemicals before starting up the surface cleaner? how about gum? can you remove with the surface cleaner or do you have to use a tip? i also noticed you used hot water...what temp?

thanks pal,

rando

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