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What to do when my 8 GPM pressure washers chemical injector is not putting out enough SH?

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I know some of you roof cleaners are pretty smart about these issues so I though I'd ask. I just started using my Honda 8 GPM pressure washer that I got from Pressuretek and after two houses it seems I have to keep going over and over the mildew and algae to get it to come off. Even then it's like it takes forever. With my old pressure washer it did a lot better. I understand that the 8 GPM washer is putting out much more water therefore less SH but what are you guys doing to make up for it. I even increased my SH to full strength. I have a feeling my SH was a little weak but I'm sure it was stronger than straight Clorox. I had about 100 ft. of hose connected in case yall ask. Thanks, Harold

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How much time are you giving it between chemical application and rinsing? If you're getting a 10% or so mix through your downstream, you should be fine with full strength SH in your bucket (plus soap).  You've got to give it some time though. Don't keep piling chemical on top of chemical. It needs air and time to work.  Also make sure your injector is working.  I use a 5.5gpm machine and it's a little too strong if I use full strength.  I normally wash with my 12 volt though, but I'm warming up to downstreaming. 

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Harold, perform a test like the following:

Insert the draw tube for your injector in to a know quantity of water, ie a 1 bucket with two gallons of water.  Let's call this bucket "SH".

Turn on your pressure washer and fill up a 5 gallon bucket with water at LOW pressure.

Turn the machine off then do some basic math based on how much water was drawn from the first bucket to figure out the ratio.  (Water to "SH")  10:1 with straight SH should clean a house all day long.  You can use that as a baseline to determine how your machine is operating and adjust accordingly.

Next time you're online, order a couple of injector rebuild kits from Bob (I like the ones made for acid - the ball is ceramic rather than steel) and another injector presuming budget allows.  They do become problematic after a while.

Look me up if you're up around the DC area.

 

 

 

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How much time are you giving it between chemical application and rinsing? If you're getting a 10% or so mix through your downstream, you should be fine with full strength SH in your bucket (plus soap).  You've got to give it some time though. Don't keep piling chemical on top of chemical. It needs air and time to work.  Also make sure your injector is working.  I use a 5.5gpm machine and it's a little too strong if I use full strength.  I normally wash with my 12 volt though, but I'm warming up to downstreaming. 

Trust me I give it plenty of time...The injector is working I'm sure of that. I just know that the other pressure washer I use to have, which was a 2-3 GPM machine worked perfectly. 

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Harold, perform a test like the following:

Insert the draw tube for your injector in to a know quantity of water, ie a 1 bucket with two gallons of water.  Let's call this bucket "SH".

Turn on your pressure washer and fill up a 5 gallon bucket with water at LOW pressure.

Turn the machine off then do some basic math based on how much water was drawn from the first bucket to figure out the ratio.  (Water to "SH")  10:1 with straight SH should clean a house all day long.  You can use that as a baseline to determine how your machine is operating and adjust accordingly.

Next time you're online, order a couple of injector rebuild kits from Bob (I like the ones made for acid - the ball is ceramic rather than steel) and another injector presuming budget allows.  They do become problematic after a while.

Look me up if you're up around the DC area.

 

 

 

Ok thanks, I will try that. At least this will let me know if the injector is doing it's job. 10:1 huh? Somewhere I read these machines came with 20:1 downstream injectors. I wonder if that's true?  See I bought this pressure washer from a guy who bought it this March from Pressuretek and it doesn't have the stock downstream injector on it. What he did have with it was a downstream injector/ bypass hookup that he also bought from Pressuretek. I have a downstream injector that was laying loose in a box, that could be the stock one. I guess it all depends on this injector so I will give it a shot like you said. Thanks, Harold

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I know some of you roof cleaners are pretty smart about these issues so I though I'd ask. I just started using my Honda 8 GPM pressure washer that I got from Pressuretek and after two houses it seems I have to keep going over and over the mildew and algae to get it to come off. Even then it's like it takes forever. With my old pressure washer it did a lot better. I understand that the 8 GPM washer is putting out much more water therefore less SH but what are you guys doing to make up for it. I even increased my SH to full strength. I have a feeling my SH was a little weak but I'm sure it was stronger than straight Clorox. I had about 100 ft. of hose connected in case yall ask. Thanks, Harold

You are talking about washing siding and not cleaning roofs right?

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Trust me I give it plenty of time...The injector is working I'm sure of that. I just know that the other pressure washer I use to have, which was a 2-3 GPM machine worked perfectly. 

Smaller pressure washers are said to draw more from downstream injectors. Jeff LeCours up in South Carolina used to purposely buy small home depot pressure washers to downstream shingle roofs with ! 

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Harold, perform a test like the following:

Insert the draw tube for your injector in to a know quantity of water, ie a 1 bucket with two gallons of water.  Let's call this bucket "SH".

Turn on your pressure washer and fill up a 5 gallon bucket with water at LOW pressure.

Turn the machine off then do some basic math based on how much water was drawn from the first bucket to figure out the ratio.  (Water to "SH")  10:1 with straight SH should clean a house all day long.  You can use that as a baseline to determine how your machine is operating and adjust accordingly.

Next time you're online, order a couple of injector rebuild kits from Bob (I like the ones made for acid - the ball is ceramic rather than steel) and another injector presuming budget allows.  They do become problematic after a while.

Look me up if you're up around the DC area.

 

 

 

The verdict is in. I filled a 5 gallon bucket up and dropped the dip stick in and I filled the other 5 gallon bucket up and hardly an inch was drawn from the other bucket. What's up with that?

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I know a guy who runs DUAL Injectors, and claims to get much more draw. I would haveb to see this, because there is only so much pressure differential to work with

Better bet is a DS injection pump that forces your DS Chem into the injector. Will allow you to inject up to 40% into a PW...which is way too heavy for siding. You *could* use your PW to do a roof in a pinch with that setup...though not recommended long term because the SH will absolutely tear apart the spray hose and gun. 

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I'd check a few obvious things first, if you haven't done so already:

Edit to add -  make sure the injector is not installed backwards!

  • Disassemble the injector and look for clogs.  Be careful if you have not done this before - little parts get lost easily.
  • Check the draw tube for clogs
  • Try the test with no wand/trigger or tips - just run the hose open.  This creates the least amount of pressure in the line and the injector should be at full draw like this.  (There is a 'cut off' with the pressure in the line, and at some point, the injector will not 'inject'.  This removes the 'pressure' variable from the scenario.

Working properly, you'll feel an obvious vacuum on the line with your finger tip.

 

If the problem is not found by these means, order a 5-8 GPM injector from Bob.  I keep a few on hand.  http://pressuretek.com/adamsinjector.html

Edited by Roof Cleaning Virginia

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The verdict is in. I filled a 5 gallon bucket up and dropped the dip stick in and I filled the other 5 gallon bucket up and hardly an inch was drawn from the other bucket. What's up with that?

What did you use as a nozzle at the spray end? You need to have *some* back pressure for the DS injector to draw properly so if you ran it open ended, it may not have drawn. Try using a soap nozzle. Also, a lot of guys will use an injector for a 3-5 GPM machine on their 8 GPM machines (that is what we do) and we get excellent results with 200' of hose. 

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I'd check a few obvious things first, if you haven't done so already:

Edit to add -  make sure the injector is not installed backwards!

  • Disassemble the injector and look for clogs.  Be careful if you have not done this before - little parts get lost easily.
  • Check the draw tube for clogs
  • Try the test with no wand/trigger or tips - just run the hose open.  This creates the least amount of pressure in the line and the injector should be at full draw like this.  (There is a 'cut off' with the pressure in the line, and at some point, the injector will not 'inject'.  This removes the 'pressure' variable from the scenario.

Working properly, you'll feel an obvious vacuum on the line with your finger tip.

 

If the problem is not found by these means, order a 5-8 GPM injector from Bob.  I keep a few on hand.  http://pressuretek.com/adamsinjector.html

The injector is installed correctly, I will check to see if there are any clogs. I did try filling the bucket without with no wand. Thanks!

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What did you use as a nozzle at the spray end? You need to have *some* back pressure for the DS injector to draw properly so if you ran it open ended, it may not have drawn. Try using a soap nozzle. Also, a lot of guys will use an injector for a 3-5 GPM machine on their 8 GPM machines (that is what we do) and we get excellent results with 200' of hose. 

I didn't use a nozzle, just an open ball valve. I will try using a nozzle this time. Thanks!

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If you are using your old injector It's probably not the right size for your new machine.

This is your answer.

"order a 5-8 GPM injector from Bob.  I keep a few on hand.  http://pressuretek.com/adamsinjector.html "

 

I'm using what came with the machine. It's for a 5-8 GPM machine. Thanks 

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I'd check a few obvious things first, if you haven't done so already:

Edit to add -  make sure the injector is not installed backwards!

  • Disassemble the injector and look for clogs.  Be careful if you have not done this before - little parts get lost easily.
  • Check the draw tube for clogs
  • Try the test with no wand/trigger or tips - just run the hose open.  This creates the least amount of pressure in the line and the injector should be at full draw like this.  (There is a 'cut off' with the pressure in the line, and at some point, the injector will not 'inject'.  This removes the 'pressure' variable from the scenario.

Working properly, you'll feel an obvious vacuum on the line with your finger tip.

 

If the problem is not found by these means, order a 5-8 GPM injector from Bob.  I keep a few on hand.  http://pressuretek.com/adamsinjector.html

I ordered a new 5-8 GPM General Pump downstream injector and still no matter where I put it at, it still only draws about an inch to an inch and a half out of a five gallon bucket while filling up another five. Is that what I should be getting?

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I ordered a new 5-8 GPM General Pump downstream injector and still no matter where I put it at, it still only draws about an inch to an inch and a half out of a five gallon bucket while filling up another five. Is that what I should be getting?

Sounds about right. The most you will get is 20-1 or 5%. So if the bucket is 20" tall then 1" is right. 

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It will work for sure on siding and not at all on roofs. You may have to let it dwell for a few minutes before rinsing and may have to reapply a few times if really bad, but in most cases one application will be enough. 

I greatly prefer using my dedicated pump to clean siding over downstreaming with a pw but both have their advantages. The pw only requires the one hose which is nice, but I can apply the mix quicker with my dedicated pump, shoot much higher, use a stronger mix and rinse in a fraction of the time. 

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Do Like Kevin suggested above. GP makes a fixed 10% injector for 3-5 gal machines, comes standard on the Pressure Pro 4gpm machine but works great on on my 8.5 also.(Still get right at 10%) I just ordered a few more. Think part # is GP100821. They're less than $15 each. Have bigger orifice so you get better draw. And I always have 200 ft of hose on.

You will use more mix than a standard injector, but on a pretty dirty house I rarely use stronger than 2 gal of SH in a 5 gal. On an average size house I'll usually go thru about 10 gal of mix. Bot a couple of the 15 gal jugs I use for my HW mix and pre-treat on drives. That way don't have to stop to make up more on job.

If you use a good soap I find I rarely need much more than about 1% SH end result and often less,  but unless it's real hot outside I may let sit for 10-15 min. I still use my 4gpm a lot for soaping and even rinsing a house and mainly use my 8.5 for concrete. I usually will soap 2 sides if nothing funky, retrace my steps and hit any real dirty spots on my way back to start point and windows if they're starting to dry, walk to truck and, turn off soap and then rinse. Sometimes I'll plug in the big machine to rinse but rarely.

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