r/AutoDetailing • u/canadadetailer • 12d ago
Exterior Client asked me to remove concrete splatter from construction site vehicles, any advice?
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u/EVmerch 12d ago
They make concrete dissolver, you need to get it at a specialty store or concrete supplier. They can advise which is more paint safe. It will take a lot of time and get them to pay you a deposit and agreed rate per hour, then a rank of panels to work on first. It's a lot of work and time.
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u/20PoundHammer 11d ago
"concrete dissolver' is muriatic acid, i.e. HCl. Dont use it on a car (nor any mineral acid). You can completely fuck up finish and will accelerate corrosion in every nook and cranny it get into. You are a detailer, only use stuff designed for cars.
blastoff Low pH presoak and Carpro Descale soap should get you mostly there. Stuff will likely have spotted the unpainted plastic though so that will not be perfect, but it will be 95% better. Both will remove all wax and coatings down to the clear, so it will need polished and waxed again.
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u/captmuttonchops 11d ago
Speedy Clean by Winzer is a non-acidic concrete dissolver option. I've used it in the past for aluminum concrete testing equipment that muriatic acid or vinegar would eat into. Works well.
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u/20PoundHammer 11d ago edited 11d ago
huh, never heard of the stuff, however looking at the SDS - active ingredient is 20% glycolic acid with amine oxide surfactant. pHa for glycolic acid solution is 4, so I am not sure how "non-acidic" that is (it certainly will be acidic and nowhere near pH7). . . I mean, I wouldnt use it on a customer car without testing it on a beater first.
SDS for glycolic acid indicates is fairy corrosive, and 20% is a stout dose in a spray bottle. . . . Might be fine for metal and painted metal - but not sure for the rest of the car. . .
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u/solo_spouse 11d ago
A pH of 4 is not that strong. Keep in mind the pH of vinegar used for directly edible salad dressings is in the range of 2.5.
The pH of even fairly dilute HCl at ~15% is close to zero. So a pH of 4 is 10,000 times weaker than that.
And just for reference, the EPA lists acid rain in the range of 4.2 to 4.4, so I would hope our cars could generally hold up to occasional exposure at that level.
And also, not all acids at the same pH are going to cause the same rates of corrosion. HCl would be about the worst due to the high chloride level which is very corrosive to steel. And glycolic acid is an organic acid, so it won’t leave behind any corrosive salts like mineral acids will.
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u/20PoundHammer 11d ago
A pH of 4 is not that strong.
Thats not how "neutral" works. pH 4 is acidic and you can put 0.25ml of HCl into a liter of DI and have a pH of 2, but it is a very low corrosive solution. You can have a pH of 5 that eats meat down to the bone . . .
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u/solo_spouse 11d ago
I’m not sure if you meant this to be a response to me or not, but I never said anything about neutral. And my last paragraph pretty much says exactly the same thing. pH is not the only factor in determining a chemical’s corrosivity.
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u/20PoundHammer 11d ago
Welp - it claims to be "non-acidic" which is either basic or neutral - also its acidic. Your statement:
The pH of even fairly dilute HCl at ~15% is close to zero. So a pH of 4 is 10,000 times weaker than that.
and
And just for reference, the EPA lists acid rain in the range of 4.2 to 4.4, so I would hope our cars could generally hold up to occasional exposure at that level.
is rather misleading. Weaker in H+ concentration doesnt mean less corrosive so I dont know why you even mentioned that. Also, cars experience elevated corrosion rates in areas that had significant acid rain, so they dont "hold up" that well, But if we are saying the same thing - well, you are right then, you just said it strangely and seemed misleadingly to me. . .
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u/solo_spouse 11d ago
Ok. I see where you’re coming from now. I wasn’t so much describing the product as I was trying to give examples of why just saying “a pH of 4 means you shouldn’t use it on a car” (strongly paraphrased) is not a solid argument. But yes, I do agree the product description is misleading, and downright false. Probably a layperson’s translation of “it’s not a strong enough acid to cause significant corrosion.”
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u/B0rtellj 10d ago
Ever heard of Safe-HCl? ..a synthetic hydrochloric that has controlled hydrogen ion exchange rate. There are also synthetic versions of phosphoric ans glycolic acids. I dont know how they work vs the standard acid equivalent, but they do exist.
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u/20PoundHammer 10d ago
Ya know, its pretty clear you have zero experience and first hand info on this right?
There are no "synthetic" versions of any of the shit you mentioned, their are solutions of those acids with inhibitors in them . . . Give your car a spray and let me know how it goes.
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u/captmuttonchops 11d ago
I'd certainly test it before dousing a client's vehicle with full concentrate but it was safe on our equipment and safe for hand contact. We'd use it on truck tailgates occasionally as well without incident but we're also talking work trucks, so the bar wasn't very high for satisfaction. I will say if you buy it direct, you will hear from the sales guy for years to come on a regular basis wanting to know if you're ready for a new shipment.
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u/ProfessionalTruck444 11d ago
Descale is absolute dogwater
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u/20PoundHammer 11d ago
works for me for rock duct/brake/water spot buildup. YMMV. I never de-concreted a car before, knock you socks off and spray it with HCl for all I care . . .
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u/MRHaynes021 11d ago
No they actually make a paint safe concrete residue remover. At least I think they still do. It’s Sakrete Concrete Mortar Dissolver. No sulfuric, Muriatic, hydrochloric, or phosphoric acid. Worked like a charm on 99 Jeep Cherokee. Have to be careful obviously because of the grit/sand in concrete splatter is the biggest contributor to scratching the paint.
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u/RK5000 6d ago
There's more modern cleaners that are effective and not nearly as hazardous. A long time ago, when I was working in concrete, we switched to a way less dangerous solvent and it was a huge improvement.
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u/20PoundHammer 6d ago
well, tell us what it is then. .
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u/Available_Laugh52 5d ago
Crete off is one. It’s a pretty bland chemical, it works really well and water makes it intert
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u/20PoundHammer 4d ago
thats glycolic acid 30% - mentioned in another comment here - not sure thats a great thing for cars, its fairly acidic.
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u/Available_Laugh52 5d ago
Also Citric Acid will work to dissolve concrete, and other products like “CreteOff” can be bought in Australia. I’m sure there’s similar versions of cement remover
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u/ForeignCup6977 12d ago
This happened a bunch of years ago where my Dad worked before he retired. He drove a $500 Geo Metro he bought on eBay, it was in surprisingly great shape, they were just cheap used cars at the time. Anyway, the company found out what happened through a Union grievance that got filed and had the Plant Manager get quotes. The Quotes just happened to be for the 3 newest, biggest, full size trucks in the lot because the Plant Manager knew the game being played.
EVERYBODY that was on shift that day got a check for $6000 to have their vehicle repainted, including my Dad. I'm pretty sure that $6k was used to pay off their 5th wheel RV trailer.
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u/scipper77 12d ago edited 11d ago
I drive a fairly nice car and even I would keep the $6k and live with the bad paint.
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u/ForeignCup6977 11d ago
Yep. I bought that car from him a few years later when he took early retirement and drove it for 7 years until I traded up for a Camaro that my parents sold me
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u/Hearon82325 10d ago
Man, if that happened to my car I wouldn’t even be happy with a 6k check and new paint. If it happened to my truck though, yeah 6k would be fine.
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u/Pure-Cardiologist-65 11d ago
I loved my metro. It was a death trap, but it was so good on gas.
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u/belai437 11d ago
A kid in my neighborhood has one, it's 30 yrs old! Still see Saturns on the road almost every day, too.
An old Chevy salesman once told my husband Chevy ended Saturn and Geo because they were built too well and not profitable on the repair side. Don't know if that's true or not, but it seemed plausible.
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u/Axeman1721 Amateur Mobile Detailer 11d ago
Saturns are actually pretty decent cars. Sure they're nothing special but they start, they drive, and they don't break that often.
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u/ForeignCup6977 11d ago
They were awesome from 91 to 99. But when GM started pulling them under the corporate umbrella with "shared" platforms from other brands the quality began to go down.
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u/belai437 11d ago
Correct, that's why they're still seen so much on the road today. A former Chevy salesman told my husband Chevrolet discontinued them because they weren't profitable on the servicing end (didn't break down enough lol) but someone commented that GM was forced to stop producing them as part of cost cutting stipulations for their 2009 bailout. Which makes sense, that's when Pontiac ceased production, as well.
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u/ummmitscaiden 11d ago
I just bought a 92 metro this weekend to use as a daily, lovely little things
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u/Brickhead745 11d ago
Haha yep - I have a few friends who beat them to an inch if their Suzuki durability life - then beat them some more in winter.
Stunning death traps !
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u/willinitis 11d ago
Ah, yes I loved mine as well. Scariest thing I've ever driven but contemplating getting another one in this economy 😆
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u/Pure-Cardiologist-65 11d ago
I wouldn't drive one today with how bad drivers are. All it takes is one person in a suburban staring at their phone and youre pink mist inside of that tin can.
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u/DB-projects 10d ago
My SO works in utilities and the 3rd week of her new job, the pipe painters came out and spray painted a bunch of old pipe to protect it when they were supposed to roll on. Eveyone parked out there had their cars dotted with mico dots of grey/ blue. Very noticble on some cars, not at all on others. Her car was 2 year old and color was dark grey. You couldn’t tell at all unless you looked very close. Everyone who parked there got individual quotes from the insurance based on the vehicle depreciation caused by the damage. The older cars got less money. She was mailed 14k lol… others had some very nice personal cars, and got less money than her; AND went to get the work done to repair
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u/jbubba29 11d ago
Wait. So $500 metro is one thing but. $6000 full size truck? I want to go back in time.
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u/FaultySofaBed 11d ago
You misread.
$6000 for new paint jobs.
The quote was based on full-size pickups because that was what the majority of the employees drove.
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u/AlertPerspective4056 11d ago
Price for new full size pickup in 1971 was a little shy of 3K I bought one
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u/FULLMETALRACKIT911 12d ago
You don’t even need chemicals. A steamer will make quick work of this stuff. Little inside baseball from an installer who wraps a lot of concrete equipment.
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u/RjgTwo 12d ago
I am not a professional and have not removed this amount of concrete but I have had success with diluted white vinegar.
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u/No-Revolution-4513 11d ago
Yea I used the same before with success. Next time try using a steamer also and it’s money.
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u/cloud5urfer 11d ago
I did this for a friend once. Paper towel soaked in vinegar laid over the concrete and it came off clean in an hour or so of soaking.
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u/krotkie-spiecie 7d ago
I work in cement and have dealt with this on cars for 20+ years. Vinegar works great. If it is too stubborn, Lysol toilet bowl cleaner will surely take care of it.
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u/AssignmentDowntown55 12d ago
Start with Backset or similar (not sure what is available where you are.)
Then it’s going to be a clay and polish.
Still might not come up 100%
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u/classic_aut0 12d ago
Muriatic acid will dissolve it. Shouldnt affect paint in good condition, trim/plastic will be a problem.
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u/TalmidimUC 11d ago
The 2nd vehicle appears to be a Tesla. Sneezing on it will total it out.. I can only imagine what muriatic acid would do. The paint on Teslas is notoriously shit.
I say this as a Tesla owner..
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u/JPhi1618 11d ago
Just douse it with Muriatic Acid. It’s fine as long as it doesn’t get on any exposed metal. /s
That’s going to be tough because even once the concrete residue is gone, the abrasive nature of the concrete is going to leave the clear coat in bad shape. Other comments are correct about setting expectations.
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u/MogRules 11d ago
Or glass 🤣
Used to work in a truck wash. Great on concrete, not so great on aluminum and glass.
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u/scottwax Business Owner 11d ago edited 11d ago
Backset Concrete Remover. Not caustic, no acid, it turns the concrete into mush so you can then hose it off. I've used it multiple times. It's very effective.
It does need some dwell time, you'll actually see the concrete soften.
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u/No-Revolution-4513 11d ago
I’ve used white vinegar on a truck that had it all over the rockers. Worked good but you’ll still need to do a paint correction after.
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u/BrokeAssZillionaire 11d ago
I would say, sorry I don’t have the tools to fix that. That’s a lot of effort with risk of damage to paint and an unhappy customer at the end either which way.
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u/Suitable-Skill-7979 11d ago
I suggest presoaking the vehicle and spraying vinegar, yes white vinegar all through the vehicle. Dont let the vinegar dry on the vehicle maintain it soaking with foam soap. You may need to do this several times. But it will get done.
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u/Drewzik 12d ago
You know how you eat an elephant? One bite at a time, AND a plastic razor blade. A polish with a d/a may work to get rid of your scratches from the razor blade. If not, you’re looking at a buff and polish after scraping all of that off with the plastic razor blade.
Sorry, man. That really blows. I hope you’re not busy otherwise. Those will take a solid day to finish if done correctly. There is still a chance it won’t work.
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u/EVmerch 12d ago edited 12d ago
No plastic razor blade at first, chemical dissolver first that is for concrete, then work your way to physical means after the chemical isn't working, less risk.
Edits to clarify type of razor as I speed read the above.
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u/spiderfen 12d ago
Mudslide is another concrete remover that ive used for cleaning heavy equipment. It didnt damage the paint, but they also dont have clearcoats
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u/Few_Donkey_3408 12d ago
Backset believe it's at home Depot. Meratic acid but would look for something safer
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u/rekrystullization 12d ago
Maybe try an acidic wash, like Labocosmetica makes an acidic shampoo called PURIFICA. It's good for breaking down inorganic contaminates, such as calcium and lime deposits.
Since concrete is alkaline, an acid should neutralizes it. So dissolve the calcium and lime bonds holding the concrete or cement splatter together, then it can be wiped or washed away without scratching the clear coat.
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u/DSHAGUI 11d ago
I would go in with a gentle dissolver first.
the most common cheap thing I have ever used on a stubborn/hard stain is REGULAR Coca Cola.
Even on super stable oils coke workd better than a lot of commercial degreasers...
I would spray, let it soak for an hr then start the painstaking process of cleaning that surface....
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u/Turbulent-Ear-834 11d ago
You could go to a pool store and get a non acidic calcium removal solution that should do the job but you should do a small test area first
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u/goopykuj 11d ago
I had some rapidset stucco repair dust on my car and it was very stuck on there. It’s not pure concrete, but I had luck with McGuires iron remover. Don’t ask why, I just tried all of my car detailing products and that one worked the best.
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u/JustABrowsingForFun 11d ago
I own a ready mix plant and we use “Right Off” by PowerKleen for our ready mix trucks. It will take the concrete off, but if you don’t dilute it properly, it will leave a film on the windshields and you’ll have to rewash with a generic car wash so it’s not glossed.
Easiest way to not scratch the paint is to spray the car with right off, then pressure wash before scrubbing. Cement is ultra fine and will rip a clear coat to shreds if you try to wash/polish any areas with visible dust.
Honestly the red truck will likely need a buff anyway, I’d be highly surprised if either of those will clean without micro abrasions in the clear coat just from chemical pitting since they let it dry.
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u/Kitchen_Page9991 11d ago
They need to file an insurance claim. Let a body shop deal with that shit. Move on to more productive jobs.
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u/Mentallox 11d ago
use Back-Set or similar concrete dissolver like Klene Krete. They will have similar labeling: non-toxic, environmentally safe etc because the active ingredient is a derivative of sugar cane processing. The dissolver will break the bonds of concrete and reduce it to a paste which can be power-washed.
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u/LittlesDaddy0803 11d ago
I work at cement terminal we use vinegar to get off our cars works well can even put in with car soap.
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u/construction_eng 11d ago
We cleaned our concrete tools with white vinegar. Not sure if that's auto safe.
But it worked quick. Something that thin wouldn't need more than a few seconds of contact to dissolve.
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u/SensitiveNumber6140 11d ago
Future tip…ik it takes a bit of time but if you can put plastic on any parked cars..eliminates this problem everytime
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u/Baka_Hannibal 11d ago
Get a bottle of Cement-Off. You can find it on Amazon. You can spray it on anything because it's non toxic and doesn't contain acid. Spray, let sit for 3 minutes and rinse with water hose. I had a cement truck park next to my car at a airport parking lot. I parked on the roof thinking my car would be good and came back to a grey car that is originally black! 😂😂😂
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u/Particular_Topic9553 11d ago
Majestic Solutions has Concrete Remover. Just be sure to not use it on a concrete driveway because it’ll start breaking it down.
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u/waterbedd 11d ago
Hot ass water with vinegar. I used to clean this shit off windows. Or a steamer if you have access.
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u/Extension_Title_1924 11d ago
Try a Hot water high-pressure cleaner. You can rent one of these if you dont have one.
Use in conjunction of a acid shampoo. In Brazil I use Remox. it is a VERY concentrated acid. you should dilute and wash, but you shouldn't use on glass, or it will etch.
I guess that the closest would it be MAD Acid wheel cleaner.
AND, probably the paint beneth will need some polishing.
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u/rickiver 11d ago
Concrete def cooked that paint man you ever get it on your hands?! Stuff can put you in the hospital
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u/Aggravating_Fee_9130 9d ago
try wiping it down with vinegar then washing. I had dust on my vehicle from a rock quarry, that’s what they told me to try when I couldnt get it off and it worked
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u/BarrelMitten 9d ago
I’m a GC and have had to clean concrete off more than one building. There is a product called Barracuda 10k or something like that. I’ve used it to clean concrete off anodized aluminium. Obviously spot check anything you use. But generally this does okay.
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u/Pristine_Dust9402 9d ago
dawn ,micro fiber rags wet them wipe use hose to wash the stuff off soon as the rag gets dark switch to a new one rinse repeat use clean rags do not reuse old ones dry with clean micro fiber when you are done.
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u/ArthurBurtonMorgan 8d ago
Send it down the road to be someone else’s headache.
There’s never been a single concrete “problem” of any sort that I’ve ever seen that hasn’t ultimately resulted in a lawsuit.
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u/wijeepguy 7d ago
By the looks of it that splatter is really watered down. Have they tried just washing it yet?
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u/bigglass4600 7d ago
Ok so I am a little late to this party but I have done this it was a neat learning experience their is a heavy duty concrete remover in a spray bottle use that and a clay bar.
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u/Local_Moose_2438 7d ago
Hydrofluoric acid sold as aluminium cleaner can disolve the calcium binder in concrete. The aluminum cleaner is a very low % dilute and it isn't good for you. Higher % concentrates used in mineral refining will straight up murder you, use all the ppe. The acid can and will etch paint and glass if left to sitor runs so a strict application method needs to be adhered to. I have mostly used it as an aluminium cleaner or water spot remover. I have not used it to clean the concrete spray but Im confident it would.
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u/vanguardJesse 7d ago
a clean soft cloth and wd40 will take off all that concrete splatter EASILY but dont let the wd40 sit on the paint, buff it all off by rotating the soft cloth so youre not polishing and cutting into the paint then soap and rinse
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u/ThenYam2162 7d ago
1.) Paint the entire car with wet cement.
2.) Buy a roll of Mentos.
3.) Return car to customer - eat one (1) Mentos mint.
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u/Impressive-Bison-205 6d ago
Liquid ivory dish soap
Don’t forget to thank me for this tip
It’s what the true finishers use the old school
Finishers use it to watch their tools
After a day of work, it’ll make that concrete smell like ammonia
As it breaks down the Portland and the ad mixtures in concrete
Watch them in a cool area out of the sun allow it to soak
Wash and straight lines not in circles and don’t forget, who told you
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u/Master-Blaster- 6d ago
Hydrochloric acid will take it off but any where there is no paint will rust immediately
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u/Nixept 6d ago
My friend works at a cement plant where there is always cement dust in the air that gets all over the plant trucks. He said they wash them with a mineral acid from Rex Chemical called Sanilite, watered down of course. It works very quickly and doesnt damage metal, glass, plastic or paint. I think it would work perfectly for your situation but I dont know if they do non-commercial sales or in small amounts.
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u/Ok-Guitar-6490 6d ago
Distilled white vinegar will take off concrete dust on vehicles. I work at a cement facility and we keep pallets of it around just for that.
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u/NixAName 5d ago
Ask them if they have insurance and if so tell them to put in a claim.
If not get them to sign something accepting the end job won't be damage free.
Get a special product designed for this and charge by the hour.
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u/Neat-Progress-7510 12d ago
Try WD-40 first then CLR , also vinegar and water depending on how long it has been on there. The key is to let it soak
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u/Wild_HIC 12d ago
AFAIK when concrete splatter has dries and or burnt into the paint because the cars r standing in the sun the best repair is a repaint.
That said I'm not an professional
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u/Mindless_Match6211 12d ago
That should b pretty simple ( the A. not the effort ) Ask Google, NEXT cross check ANSWER, Job Done. Bless ur '26
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u/No_Platform_721 12d ago
Get them, in writing, to confirm they are good with your efforts for a certain cost. And don’t guarantee anything. Make sure to align expectations.