Removing red chalkline? I need some advice please.

[djjsr]

I had a new concrete driveway done about 9 months ago. They used a red chalk line to mark the cut lines. According to Irwin, it's "permanent" and it does not wash off. The contractor said that weather will eventually take care of it but now I have a pinkish hue all over my driveway. I'm not fond of pink.

Anyone know how to clean this stuff off without discoloring the concrete? I already tried some diluted muriatic acid on a small area and it did remove the chalk but left the concrete with a light brown tint. Better than pink but not quite what I was hoping for. Pressure washer didn't help.

Any advice is appreciated.

 

[4xdog]

My go-to for any tough stain is Super Clean, the purple stuff, and a stiff brush -- maybe even a wire brush in your case.

 

[Ilikeike]

I'd think a pressure washer, and a jug of the hardware store driveway cleaner would do it.

 

[kd3pc]

red is incredibly difficult to remove, I would start with a brush and a bit more aggressive before the pressure washer.

 

[rayra]

That idiot contractor should be whipped for using red on a driveway (or any other high visibility location). They had to know of its permanence. It's practically vandalism to deliberately deface a surface people paid a lot of money for.

 

[readhead]

If a concrete guy showed up on my job with red or black chalk I would send him down the road. Might want to talk to a concrete supply house for recommendations. You don't want to damage the surface and have a new problem.

 

[pizza]

maybe try paint stripper or acetone? dunno

 

[Feralghoul88]

Make the contractor deal with it. Dont pay them until the "weather takes care of it"

 

[captaindiode]

Have you tried white vinegar?

 

[brownbagg]

they call it dead red for a reason

 

[nadogail]

When the slab is cut, the chalk marking the cut lines should be cut away.

 

[BillK]

If it is still there after 9 months it must be some crazy stuff Have you tried bleach ? I have used it on my patio a few times and it turns the concrete pretty white but gets rid of any stains. After a while in the weather it evens back out.

 

[yelchevelle]

Red is tough. I feel like whatever you do is escalating wear on the surface. I have never tried it, but may try some clr or some other kind of rust remover. I would guess the red is red oxide derived, but that’s pure speculation.

 

[finn]

I have red lines on my metal building that’s probably twenty years old.

the lines laugh at my pressure washer, and scrubbing is futile.

I just consider them part of the patina.

If the lines were on asphalt, I would try a can of flat black spray paint on a section. If the paint covers the lines in an inconspicuous place, you have your answer.

 

[Zeke]

Well this may be sorta out there, but I deal with colors all the time. If you have a 'pinkish hue' then mist it with green dye stain. Green kills red. Mohawk sells a rattle can of the stuff for around $10.

 

[djjsr]

The best results I've had so far is 40 grit heavy duty sandpaper on my small 3x21 beltsander. It actually leaves a nicer finish but I'm not going to do the whole 20' x 60' drive with something that small. I'm thinking about renting one of those big floor sanders. What could possibly go wrong?

 

[Norcal]

I would not try a pressure washer, too easy to mar up fairly green concrete, maybe a very stiff brush & some powdered laundry detergent. They should have used white chalk.

 

[K'ledgeBldr]

Have you tried white vinegar?

yep- white vinegar will not entirely remove the stain, but it will diminish the stain considerably. But, after 9months you may already be at that “diminished” point.

Personally, I’d part the Red Sea (pun intended) and go after the contractor= paid or not!

 

[pizza]

have you tried asking the manufacturer of the product? maybe they have removal tips. even though it's advertised as permanent.

also, imo it's a good idea to name the product (irwin red chalk?) and show pics of the affected part of the driveway. that's how you can get the most productive answers. not sure why people rarely do.

Chalk Reels & Chalk | IRWIN

IRWIN® STRAIT-LINE® Chalk Reels, chalk, and reel/chalk combo packs let you get straight to the point. A variety of reels are available with traditional or quick rewind, aluminum or ABS housings, large or extra-large chalk capacities, nested hook docks, extra-wide prong hooks, and anti-jam spools.

www.irwin.com

is this the stuff?
if so, here's the SDS:

https://www.irwin.com/uploads/documents/66_IRWIN_Chalk_SDS_Red_Permanent.pdf

as @yelchevelle surmised, it's iron oxide.

looks like it's basically 7 parts chalk dust to 3 parts iron oxide.

you can also research how to get rust stains out of concrete. maybe that will turn up some ideas. gl

edit: sounds like pros might use TSP and oxalic acid to remove rust from concrete. try those too?
this product looks pretty promising: Singerman Laboratories Rust Stain Remover for Concrete

 

[The Cobbler]

red chalk is a biatch . too bad they used it.
what about a concrete dye over the entire surface ? I would talk to the contractor & see if they would offer to do it for you. or if they have any suggestions

 

[RivennHewn]

Red chalk has dye in it. Once wetted, it soaks in/penetrates the concrete.

Really not much that can be done besides waiting for the sun to make it fade away.

 

[Nthill93]

Try oxalic acid I use it to remove rust stains from natural stone. Tsp clr muristic acid etc couldn’t get the stains out but oxalic did. Make a paste out of it and scrub with a hard brush then let it sit a couple minutes then rinse then power wash.

 

[Showkey]

As so many mentioned………you live with it it’s “dyed in the wool” so to speak.

You too aggressive with acids and your going to have a large discolored strip that may be less red.

 

[PoorUB]

Iron oxid in the chalk? Iron out!

 

[backupbeeper]

I’d like to know what’s it’s made of

I paint labels on the concrete in gas station parking lots for the lids to the monitoring wells , and the best oil base enamel paint wears off in a few months .

 

[Rusted Nut]

I have a rule on my job sites - absolutely no red chalk! The only way I know of to remove it from concrete is waiting for it to weather off, which could be several years. A few years ago we broke out a slab because someone used red chalk on it and it was an exposed slab with sealer.

 

[qdvuu]

I've never hired a concrete contracting firm to pour a residential driveway so I'm not up to speed on the paperwork/contract involved. Does it typically say something in detail about what the end product is and isn't? As far as adding a clause, would the contractors balk if I wanted to add one stating that the end product won't have markings/discolorations or other evidence of the construction materials (such as red chalk)?

 

[finn]

Good luck. My shop building was, by estimation, put around twenty years ago. They used red chalk to marl the purloins to set the siding screws. Although fairly faint, you can still see the chalk lines.

The lines laugh at a pressure washer.

 

[nadogail]

That temporary chalk line is about as long lived as a temporary tax.

 

[duga]

Have you tried blue Dawn?

 

[Milton Shaw]

You might try a large floor buffer with scrub brush. A little tide or other soap should help to dimmish the stain. Concrete cleaner would be rough on any shoes you tried to wear, don't do it in sandals or your feet will regret it.

 

[bb29510]

it be easier to just paint the drive way red, it aint coming up