Hey guys. I have a job i completed and the irin stains on the walk way and light but not gone. I used a rust remover called goof off… antd the next day i tried a product called white cap… After researching, I just ordered some oxalic acid. Trying to figure out the mixing ratio for my 2 gallon sprayer. Also what do you guys find the best technique is for using this stuff? I have to be careful as there is grass and plants in the area. Thanks!
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It should have some directions on it on how to mix it and how to make it stronger if the first try doesn’t work. Also, there are a ton of threads here where it’s being discussed. Read them over and put together what you think will work for you, then try it out and revise from there.
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On smaller things get F9 or Rust remover plus. You can stretch it. F9 works better anyway in my opinion.
I just had a job were I used a ton of oxalic though and I went in hot at 1 cup per gallon. The recommendation called for half that. It worked beautifully, but not much faster than if I had followed directions. Moral of the story is start at the recommendation and go up if you need to.
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squidskc;
F9 is REALLY expensive, and they recommend a 1 partH2O to 2 parts F9 ratio. My question is how much should one charge to pressure wash, come back and apply F9, come back to rewet and brush out, and finally wash off the remainder of the F9 from the now hopefully unstained concrete?
This seems like a colossal undertaking. Maybe there are shortcuts? Is there an industry standard price for applying F9? Finally, their website boasts an authorized applicator designation. Have you pursued that avenue as a source for leads?
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You can stretch F9 1:1 and tackle most rust with it. Fill a Zep spray bottle and you’ll use 10 squirts on most little rust stains a house has. Or you can use Bar Keepers Friend, but it takes longer.
As far as pricing, I’m certain we’re the most expensive exterior cleaning contractor in Kansas City, but I could give you 100 reasons why our customers don’t care. People always ask about pricing and it’s the 9 little things you do to the 1 house wash that customers are paying for.
I don’t think there’s an industry standard per se. If you don’t want to use F9, I think Rust Remover Plus is a little less expensive and has a lot of great feedback. If supply costs or overhead are a concern stick with Oxalic acid. At the end of the day, it just takes a little longer to do the job 90% as well as the F9 or RR+.
Like they say, if it’s not broke don’t fix it.
As far as the “Authorized Applicator” designation, I haven’t researched it nor would I probably. A before and after picture of a previous job will sell more than a designation in my opinion. Most people have zero clue what a designation really means to them. Check out a recent post we put on our facebook page about rust removal. The before and after pic got us a lead. Then check out our posts about being Kansas City’s highest rated exterior cleaning company with badges from HomeAdvisor. Crickets. Not a word or a lead from anyone. Lol.
Okay guys here is what i fiund today when i revisited the property.
Ive already treated these areas with 2 different rust removers. I need to figure out what will take these stains out without buying a bunch of different products. The homeowner has mentioned oxalic acid…
Didnt you order some oxalic? Have you tried it? What about the F9 that was suggested? Either of those should work.
I had it ordered on amazon but found it cheeper locally. Then I seen the mention if F9 and was up in the air about it and cancalled to amaxon order.
Okay, well check back after you try F9 or oxalic.
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F9 is expensive, but worth it. If and only if you can get your customer to cover the cost and make money.
Give them 2 options. Do you want this stuff 75% gone or 90%? Just never say 100. Lol
The last 10% is for knocking their socks off anyway.
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OK, finally received both the oxalic AND the F9. I’m going with squidskc and apply the oxalic first and follow with the F9 if the customer is willing to pay. I’m thinking $.30 sq ft for pressure washing followed by oxalic, and another .50 sq ft for F9 treatment. Does that sound reasonable? Too reasonable? Too much?
A couple of questions: Should I allow the concrete to dry fully before applying the oxalic (1/2c to 1 gal)?
Squidskc, you suggest localized spraying from a ZEP bottle with the F9 for smaller stubborn stains. Should THAT concrete be dry before application?
Thanks, guys. I’ll load photos of my work with details to further this discussion.
Oh, one more thing: do multiple applications of oxalic accomplish any more than a single application accomplishes?
I would direct that question to Bob at PressureTek via email.
@MrSparkleVA hey George. Where at in VA are you located? I was stationed in Norfolk/Va Beach for 5 years and stayed in VA Beach for another 7. I really love it out there.
Anyway, I always “post treat” with oxalic or F9 so everything’s usually a little damp. If not I’ll prewet it.
As far as pricing that’s up to you. How can you make the money you need/want and the customer gets what they want at a fair price?
Sometimes multiple applications will yield better results. Sometimes, just like a house wash, the stain stops changing colors and you gotta call a spade a spade.
Here’s one example of how I went in with a hotter mix, multiple repeated treatments, rinsing in between, and this stain went away in about 15 minutes.
Concrete you have to let it dwell a little longer, and with the localized spraying it may take some blending with the surrounding area unless you plan on treating the entire area with oxalic. Then again… it may not. Had it both ways.
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I do multiple applications if it’s not coming clean. I up the strength each time too. I also agitate it with a still bristle brush sometimes.
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Good point and reminder. On concrete I always agitate with a brush. On paint and vinyl I haven’t found it necessary, but on concrete I think it’s a must.
You cleaned that with Oxalic? Darn nice job whatever you used.
Spent the day cleaning windows and driveway for wealthy dentist in VA BCH. I live in Chesapeake. I thought you might be ex-NAV with your moniker. I’m doing pretty well over in VB, but when I started I really didn’t want the travel.
