Hey guys i’ve been running a pressure washing business for almost a year now and i’ve recently been getting into the use of chemicals. we had this job that had seemed like it would be a good chance to try bleach, so we used it on an old ryobi 3000 we no longer use anymore in the on board chem tank at 1:20 dilution. even with 12.5% straight SH obviously that wasn’t a very powerful solution. We had started to pre treat the wall when we noticed these white patches like i’ve never seen before. i didn’t manage to get an after picture of it but it was on the darker spots you can see in this picture here. Everywhere else seemed to be ok and was slightly working, but for those darker areas it was horrific. looked like a big patch of white chewing gum i want to say. this has scared me away from chemicals so i’m here to see what kind of explanation i can get for this. and some advice on how to avoid horror stories like these while still learning my way around chem use. Thanks everyone, looking forward to y’alls responses.
That’s going to need more than what a downstream injector can get on that wall. I’m having a hard time picturing chewing gum looking stains on what seems like brick, situations like this you need an after photo to get any meaningful and usable advice.
Maybe the white patches is where it was actually cleaning. Although, I’m with Muscle in that you’ll need a stronger mix.
If you haven’t been using bleach over the last year have you just been blasting everything with pressure? Beach or SH is your friend. It’ll speed up your process and do a better job at cleaning. It’s by far the number chem we all use. Most of us here order it by the 55 gallon drum
or even a handful at a time. Down streaming works perfect for vinyl houses. Once you get into the brick or concrete you might need a stronger mix if there are a lot of organic stains. That’s when you pull out your 12 volt. If they banned SH I’d probably quite washing because that’s how much easier it makes life as a pressure washer.
Expected better from you 
I was just trying to spell like you Arkansas boys do. I figured it would help your self esteem.
I don’t believe it’s a brick, it’s more of a stone. think of a castle like structure.
Correct i’ve just been using high pressure water. i haven’t done siding before just hard surfaces with a surface cleaner mostly. done a fence here and there but as i’m now looking into 2-3 jobs a day i realize now need to learn to use chemicals. When i did this job last week i didn’t realize 1:20 was as bad as it ended up. however it was really concerning what i saw on this mans house. i figured since it was ONLY in the dirtiest spots that maybe whatever bacteria was on the surface was somehow eating away the surface, but i’m sure as we all know you’re guess is never right when you’re a noob. got a lot to learn.
i now have a DS injector with 1:4 dilution and a 10 gal bucket of 10% bleach with some dawn soap.
Ditch the Dawn dish soap. It has been known to cause issues on house washes. Pickup a good surfactant like Elemonator or Slo Mo.
I’ve heard of elemonator, just put an order in on pressuretek for some right now.
I’m with everyone else in that the white patches were caused by a chemical reaction with your bleach mixture and the contaminants on the wall. In masonry, you’ll get used to seeing these reactions and literalling hearing the hiss of chemicals doing their job.
For your project, I would look at ReKlaim Cleaner. It has a cleaner that gets sprayed on, then an activator that gets sprayed on and causes a chemical reaction within the stone and on the surface. Agitation with a brush helps. Rinse off with high flow, low pressure. Then you spray on Limestone Afterwash and rinse to neutralize the ph.
If that all is either too much or not in your budget, look at Heavy Duty Restoration Cleaner or SafRestorer.
The bottle literally says not to mix with bleach
Some of them do
Dawn is dawn. Don’t mix it with bleach. Dawn contains ammonia and your mixing that with bleach. Mixing those 2 chemicals creates toxic chloramine gas. Just don’t do it
Here’s the MSDS, show me where it says ammonia.
It’s main cleaning agent is ethanol.
We bought/used nearly 1500 gal last season.
Swear it did. What I do know is that dawn never suggests mixing bleach with their product
I’m definitely no expert. My understanding is that the amines listed is a derivative of ammonia. There is a chance of chemical reaction some notice it some don’t. Some soaps have more chance of reaction than others.
Now some of the various Dawn formulas have 10-15% sulfuric acid, maybe that is what reduces the SH potency.
