Oxalic Acid

[GrimeBusters]

What's your average dwell time using Oxalic Acid ? Has anyone experienced a problem if/when the Oxalic dry's before it is rinsed ?

I'm doing a 3000+ sq ft driveway later this week with some rust stains. Unlike others I have done in the past, the original sealer applied soon after the concrete was poured (maybe 5 years ago) is starting to fail. I'm hoping either the pressure and heat will remove the remaining sealer that is failing, or the Ox will assist.

As always, your feedback and suggestions are much appreciated.

[Lenny Schrecengost]

I do not know if the ox. Will do anything to the sealer but we do not rinse the acid

[GrimeBusters]

I usually apply the Oxalic acid then let dwell 10 minutes and rinse with the ball valve. Allows me to see if the rust stains have disappeared.

Not sure what, if any effect it will have on the failing sealer. I have already explained to the customer about the failing sealer, and have made no guarantees to the condition of the sealer once my scope of work has been completed. The HOA is only concerned with the rust stains.

Thanks for your input Lenny.

[FLORIN]

Not sure what your surrounding areas are but I did a drive with red sealer on and I just put strong s. hydroxide and heat and it took most off. Then applied ox to nutralize and in your case to remove rust.

[PressureWashE]

Rinse?? whats that?? After we clean the driveways, we pray down a light coat of ox and leave. I just tell the customer not to drive on it, or walk on it until it dries.

[GrimeBusters]

Well, just as I suspected, the job turned into a disaster. Got the rust out after several applications of Oxalic, and did the entire driveway with 1 application of Ox. But when it dried these stains are left. I'm left to assume it's the crap sealer that I saw was failing. Only in the couple ares the customer had heavy rust and hard water stains did this aftermath happen, the same areas I applied several (maybe 3) applications of Ox.

Of course the customer is mad, and I'd probably be also. It is stated in the proposal that they signed that I pointed out to them that the sealer appeared to be failing.

I want to make this right for the customer, since customer satisfaction is always my goal. If it is/was the original sealer that failed, is the answer to remove the remaining sealer ? Or will SH help in this case ?

This is all new to me folks, never experienced an end result like this before. As always any suggestions or recommendations would be greatly appreciated.

The resolution doesn't appear too good on the forum. I can email you better resolution pictures, just shoot me an email.

GrimeBustersPressureWashing@msn.com


http://h1.ripway.com/RAIAJim/SDC12901.jpg

http://h1.ripway.com/RAIAJim/SDC12902.jpg

http://h1.ripway.com/RAIAJim/SDC12903.jpg

http://h1.ripway.com/RAIAJim/SDC12904.jpg

[FLORIN]

Am I reading your post correct that the discoloration/stain is only where you applied 3 times the ox?

[GrimeBusters]

Am I reading your post correct that the discoloration/stain is only where you applied 3 times the ox?


Yes, only in the area(s) where I needed several applications of OX.

[FLORIN]

Hmmm. Only speculating... maybe etching due to the 3 apps instead of 1 of the rest of the drive. Getting further into the "fresh" concrete

[GrimeBusters]

Hmmm. Only speculating... maybe etching due to the 3 apps instead of 1 of the rest of the drive. Getting further into the "fresh" concrete


That was my assumption, hoping to hear more feedback from others.

I did state verbally when I did the proposal that the sealer appeared to be failing and I could not guarantee what effect, if any the ox acid would have on the failing sealer. It is also stated in my proposal.

Worse case scenario would be, I assume, is that all of the remaining sealer would need to be removed.

I have contacted my insurance company, just in case.

Thanks for your reply FLORIN.

[Guy B]

You may need to use a HF acid, alum. brightner is what I use in some applications. This may take the rest of the sealer up.

[plainpainter]

The few times I took rust off of foundations with OX, it always left an area that was much lighter than the surrounding concrete in the pattern of where the rust was. And it didn't matter if I sprayed an area much larger - only where the rust stain was - it becomes much lighter. Part of doing this business is grounding the prospective customer about the results. People equate clean with looking brand new, you have to educate them.

[jefferyjacobs]

What do you spray it with? I would like to start spraying all the concrete I do or at least have a upgrade of "concrete brightning". Can you spray it with a sureflow or a Fatboy?

[GrimeBusters]

I use a quality pump-up sprayer like a Chapin http://www.chapinmfg.com/ShowSprayerA.asp?ModelNum=1949

[Doug Rucker]

Anybody else rinse after applying Ox Acid?

[Bill Booz]

Yes, we always rinse all chems on the ground level before leaving a job. There is Too much risk associated with leaving chem for me to sleep good.

Sorry, I don't really have a solution to this one. I can't see a pic?? Did you post a pic?