# Concrete Rust Removal **URL:** \ **Category:** Residential\ **Created:** [December 9, 2020, 8:20pm UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875 "2020-12-09T20:20:14Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![sixsolve](https://pressurewashingresource.com/community/letter_avatar_proxy/v4/letter/s/f19dbf/32.png) [@sixsolve](https://pressurewashingresource.com/community/u/sixsolve)\ **Post date:** [December 9, 2020, 8:20pm UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/1 "2020-12-09T20:20:15Z")
Hello all, I’m a long-time searcher and reader. Thank you all for the information. I cleaned a driveway with a rust stain left by a dripping golf cart. I treated with mutiple coats of oxalic acid mixed at more than 1 cup per gallon. The OA was brushed into the concrete after each application, allowed to dwell for 5-10 minutes, and then washed with hot water. The rust stain got 30%-50% lighter. A few days later I received negative feedback, and I plan to make it right by providing a refund or improving the stain. I did not properly discuss the rust stain before beginning work. Am I doing something wrong while using OA? I have used it on a few spots here and there, but I have not been impressed overall. I told the customer that I can use F9, but it is my understanding that I will need to evenly apply it to the entire driveway. If I could spot treat this area, please let me know. I don’t plan to treat the hole driveway with F9 at the original price. Any other recommendations are also appreciated. ![20201205_104851](https://pressurewashingresource.com/community/uploads/default/original/3X/a/3/a3106fb7a0531a6de28cffddc66cca3d49131672.jpeg) ---
**Author:** ![DJPWS](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/djpws/32/36461_2.png) [@DJPWS](https://pressurewashingresource.com/community/u/DJPWS)\ **Post date:** [December 9, 2020, 8:24pm UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/2 "2020-12-09T20:24:53Z")
You can use F9 Barc the way Craig explains to use it for this type of stain and either treat the whole pad and charge accordingly or inform the customer that you can spot clean and try to feather out the edges to blend it but it will be brighter in that spot of the drive ---
**Author:** ![FatFIRE](https://pressurewashingresource.com/community/letter_avatar_proxy/v4/letter/f/e9c0ed/32.png) [@FatFIRE](https://pressurewashingresource.com/community/u/FatFIRE)\ **Post date:** [December 9, 2020, 9:42pm UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/3 "2020-12-09T21:42:23Z")
Battery acid stains are super tough. According to what I’ve read, you need f9 double eagle to neutralize, then fo barc at full strength 2x (I believe, the cookbook has the exact info in more detail). If you didn’t promise them perfect then let them know there is a probability that that one area MAY be very white compared to the rest. ---
**Author:** ![Racer](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/racer/32/4931_2.png) [@Racer](https://pressurewashingresource.com/community/u/Racer)\ **Post date:** [December 10, 2020, 8:28am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/4 "2020-12-10T08:28:34Z")
With the F9 he does rec doing at least the entire section, not the entire drive. But that one’s not that bad. I’d just try spot treating it and tell customer it’s going to be a little lighter. You can blend it in pretty easily. Hopefully you learned to talk with customer regarding rust stains are not included in basic concrete cleaning. You don’t need Double Eagle to neutralize. I was using F9 years before he came out with double eagle. Any base soap or degreaser will do. ---
**Author:** ![sixsolve](https://pressurewashingresource.com/community/letter_avatar_proxy/v4/letter/s/f19dbf/32.png) [@sixsolve](https://pressurewashingresource.com/community/u/sixsolve)\ **Post date:** [December 11, 2020, 4:43am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/5 "2020-12-11T04:43:22Z")
Thank you all for your recommendations. Unfortunately, I have not heard back from the customer. If I do, I will recommend the spot treatment. ---
**Author:** ![sixsolve](https://pressurewashingresource.com/community/letter_avatar_proxy/v4/letter/s/f19dbf/32.png) [@sixsolve](https://pressurewashingresource.com/community/u/sixsolve)\ **Post date:** [January 24, 2021, 4:13am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/6 "2021-01-24T04:13:47Z")
How do you all typically spot treat with F9 Barc for small rust stains such as those from patio furniture? Do you spot treat before or after you clean the concrete? I understand this product is supposed to be used on a dry surface, so would it be ok to hit small spots with it before pressure washing? I sprayed a few small spots with it after washing while the concrete was still wet, and it did nothing. It would be great to save the second trip needed in order to apply it to dry concrete. ---
**Author:** ![SurfaceTherapy](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/surfacetherapy/32/13463_2.png) [@SurfaceTherapy](https://pressurewashingresource.com/community/u/SurfaceTherapy)\ **Post date:** [January 24, 2021, 5:16am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/7 "2021-01-24T05:16:16Z")
leaf blower to dry concrete quicker ---
**Author:** ![MrSparkleVA](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/mrsparkleva/32/13908_2.png) [@MrSparkleVA](https://pressurewashingresource.com/community/u/MrSparkleVA)\ **Post date:** [January 25, 2021, 7:28am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/8 "2021-01-25T07:28:10Z")
Hydrofluoric acid (aluminum brightener) has an impressive gift at neutralizing rust stains. QUICKLY ---
**Author:** ![Molski](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/molski/32/26855_2.png) [@Molski](https://pressurewashingresource.com/community/u/Molski)\ **Post date:** [January 31, 2021, 1:00am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/9 "2021-01-31T01:00:45Z")
@sixsolve clean it first then do the treatment. F9 has a free app now that you can download with all the processes. I’ve always found that type of work to be somewhat frustrating unless you really set expectations. I hate spot treating it too and at least go joint to joint or just do the whole thing with a rust remover. I’d rather spend my time washing a house or a roof. And oxalic acid is much much cheaper and can do a decent job sometimes. ---
**Author:** ![BobsPressureWashing](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/bobspressurewashing/32/44972_2.png) [@BobsPressureWashing](https://pressurewashingresource.com/community/u/BobsPressureWashing)\ **Post date:** [May 25, 2024, 2:54am UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/10 "2024-05-25T02:54:59Z")
> [@Racer](#): > > You don’t need Double Eagle to neutralize. I was using F9 years before he came out with double eagle. Any base soap or degreaser will do. @Racer How does that work, Rick? Apply the base -soap or -degreaser and then the BARC F9? If you don’t mind, what would be the process for that? Sodium hydroxide recipe (I have some on hand)? Then the process itself? I have the F9 cookbook, if that would help explain it…? ---
**Author:** ![Racer](https://pressurewashingresource.com/community/user_avatar/pressurewashingresource.com/racer/32/4931_2.png) [@Racer](https://pressurewashingresource.com/community/u/Racer)\ **Post date:** [May 25, 2024, 2:30pm UTC](https://pressurewashingresource.com/community/t/concrete-rust-removal/28875/11 "2024-05-25T14:30:06Z")
I generally use BARC Process #2, method B unless a lot of organic growth also. The water when you surface clean will dilute it or I just use my HW mix when I clean after treatment, if I’m cleaning drive anyway. If just a spot or area, the water will dilute it fine. It’s not that strong an acid.