wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.

Any ideas appreciated.

On Sep 9, 5:49*pm, bill jensen wrote:
wow! *Is there anything that will remove it? *I've tried bleach,
cleanser and even Goof-off with no luck. *I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. *fyi, the slab is just 3 days new so I've been holding off
on acids.

* Any ideas appreciated.

Do you mean chalk...... like chalkline chalk?

If so, ignore it. It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

On Fri, 09 Sep 2011 17:49:16 -0700, bill jensen wrote:

wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.

Any ideas appreciated.

water

time is on my side

On 9/9/2011 6:21 PM, DD_BobK wrote:
On Sep 9, 5:49 pm, bill wrote:
wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.

Any ideas appreciated.

Do you mean chalk...... like chalkline chalk?

If so, ignore it. It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

Yes Bob, chalk line chalk. Thanks for you input.

On Sep 9, 7:49*pm, bill jensen wrote:
wow! *Is there anything that will remove it? *I've tried bleach,
cleanser and even Goof-off with no luck. *I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. *fyi, the slab is just 3 days new so I've been holding off
on acids.

* Any ideas appreciated.

I got the 'bright idea' to use a chalk line when I was hanging
wallpaper. Some red chalk got the wallpaper and nothing would remove
it. Been there for 12 years now.
Yeah, I know that didn't answer your question but thought I'd share
the experience anyway.

On Fri, 9 Sep 2011 18:21:34 -0700 (PDT), DD_BobK
wrote:

On Sep 9, 5:49*pm, bill jensen wrote:
wow! *Is there anything that will remove it? *I've tried bleach,
cleanser and even Goof-off with no luck. *I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. *fyi, the slab is just 3 days new so I've been holding off
on acids.

* Any ideas appreciated.

Do you mean chalk...... like chalkline chalk?

If so, ignore it. It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

He already did permanent damage by putting bleach on 3 day old
concrete. The surface will probably deteriorate and flake off where
the bleach was used.

The best solution at this point would be to rip it up and pour new
concrete.

This is proof how amateurs can destroy something in seconds by doing
something stupid. That chalk was hurting nothing and would have
vanished in a short time just from rain and normal use. Now the whole
job is ruined permanently. Even if the surface does not crack off,
that bleach will show up years from now when the chalk was only a
memory.

Red wrote:
On Sep 9, 7:49 pm, bill jensen wrote:
wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and
leave smooth area. fyi, the slab is just 3 days new so I've been
holding off on acids.

Any ideas appreciated.

I got the 'bright idea' to use a chalk line when I was hanging
wallpaper. Some red chalk got the wallpaper and nothing would remove
it. Been there for 12 years now.
Yeah, I know that didn't answer your question but thought I'd share
the experience anyway.

Irwin says the red is "Visible after weeks of weather exposure and jobsite
wear", and calls it permanent. The "standard" is "temporary".

On Sep 9, 6:30*pm, bill jensen wrote:
On 9/9/2011 6:21 PM, DD_BobK wrote:









On Sep 9, 5:49 pm, bill *wrote:
wow! *Is there anything that will remove it? *I've tried bleach,
cleanser and even Goof-off with no luck. *I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. *fyi, the slab is just 3 days new so I've been holding off
on acids.

* *Any ideas appreciated.

Do you mean chalk...... *like chalkline chalk?

If so, ignore it. *It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

Yes Bob, chalk line chalk. *Thanks for you input.

As Bob F posted, if depending on the type of chalk it was, the marking
could be there a LONG time.

scroll down & checkout page 48
http://www.irwin.com/uploads/product...ing-layout.pdf

unfortunately, it looks like the "red chalks" are the longest lived
ones.
My suggestion remains the same, leave it alone and it will eventually
fade.

cheers
Bob

On Sep 10, 1:00*am, DD_BobK wrote:
On Sep 9, 6:30*pm, bill jensen wrote:









On 9/9/2011 6:21 PM, DD_BobK wrote:

On Sep 9, 5:49 pm, bill *wrote:
wow! *Is there anything that will remove it? *I've tried bleach,
cleanser and even Goof-off with no luck. *I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. *fyi, the slab is just 3 days new so I've been holding off
on acids.

* *Any ideas appreciated.

Do you mean chalk...... *like chalkline chalk?

If so, ignore it. *It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

Yes Bob, chalk line chalk. *Thanks for you input.

As Bob F posted, if depending on the type of chalk it was, the marking
could be there a LONG time.

scroll down & checkout *page 48http://www.irwin.com/uploads/products/brochure/270_2011-06-02-marking...

unfortunately, it looks like the "red chalks" are the longest lived
ones. *
My suggestion remains the same, leave it alone and it will eventually
fade.

The red chalks will last and last and last and... The OP should
practice ignoring the chalk lines immediately if not sooner.
Otherwise start considering Plan Bs - masking.

R

On 9/10/2011 2:21 AM, RicodJour wrote:
On Sep 10, 1:00 am, wrote:
On Sep 9, 6:30 pm, bill wrote:









On 9/9/2011 6:21 PM, DD_BobK wrote:

On Sep 9, 5:49 pm, bill wrote:
wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.

Any ideas appreciated.

Do you mean chalk...... like chalkline chalk?

If so, ignore it. It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

Yes Bob, chalk line chalk. Thanks for you input.

As Bob F posted, if depending on the type of chalk it was, the marking
could be there a LONG time.

scroll down& checkout page 48http://www.irwin.com/uploads/products/brochure/270_2011-06-02-marking...

unfortunately, it looks like the "red chalks" are the longest lived
ones.
My suggestion remains the same, leave it alone and it will eventually
fade.

The red chalks will last and last and last and... The OP should
practice ignoring the chalk lines immediately if not sooner.
Otherwise start considering Plan Bs - masking.

R

I suspect it bothers OP more than anyone else that sees it, especially
since everyone else will assume it just happened. I wonder if rubbing in
a poultice of the dye (in some shade of gray) used for tinting concrete
or grout, or even plain old cement dust or powder, would take the edge
off, or just make it worse? (not advocating it, just curious)

But I mostly agree with the others- sunlight and weather and time, maybe
lots of time, are likely the only real cure at this point.

--
aem sends...

On 9/9/2011 7:17 PM, wrote:
On Fri, 9 Sep 2011 18:21:34 -0700 (PDT),
wrote:

On Sep 9, 5:49 pm, bill wrote:
wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.

Any ideas appreciated.

Do you mean chalk...... like chalkline chalk?

If so, ignore it. It will wear off in time.
I believe there is a high potential for doing permanent damage to your
"green slab", let it cure.

cheers
Bob

He already did permanent damage by putting bleach on 3 day old
concrete. The surface will probably deteriorate and flake off where
the bleach was used.

The best solution at this point would be to rip it up and pour new
concrete.

This is proof how amateurs can destroy something in seconds by doing
something stupid. That chalk was hurting nothing and would have
vanished in a short time just from rain and normal use. Now the whole
job is ruined permanently. Even if the surface does not crack off,
that bleach will show up years from now when the chalk was only a
memory.


I tried it in a small inconspicuous spot and rinsed it well. If there
is some damage how long before it shows?

On 9/9/2011 7:49 PM, bill jensen wrote:
wow! Is there anything that will remove it? I've tried bleach, cleanser
and even Goof-off with no luck. I think a wire wheel may do it, but it's
a broom finish and i don't want to knock that off and leave smooth area.
fyi, the slab is just 3 days new so I've been holding off on acids.

Any ideas appreciated.

You could try one of those powerful laser pointers. There are some that
will burn paper but I'm not sure how much money you would like to spend
on a new toy that could have any number of unexpected uses. ^_^

TDD

Paint it with cement.

simple,Green scouring pad and a little water if it takes more than that then use a 120 grit Sandpaper these are stains they don't just magically disappear I've snapped lines that were bogus and tried to cleaning them off minutes later and they were extremely hard unless you have a little water and Green scouring pad it works like 400 grit sandpaper and if its been in there for a long time you may need to go a little more aggressive with sand paper yeah that takes some elbow grease it's a stain most times when you snap lines on a slab you want them to be permanentbecause they're usually being covered up by framing

I'm no concrete expert, but I don't see any reason why putting bleach on fresh concrete would do any more harm than putting water on fresh concrete. Admittedly, you don't want to do that, but after 3 days the concrete should have cured enough that it's not going to be harmed by that little bit of bleach. Where I live they paved the street beside my building with concrete and the following day it rained cats and dogs. But, the concrete wasn't damaged and I drive over it every day. I fully expected it would be ruined, but it cured fine and wasn't damaged at all. Perhaps it was the slope they put on the concrete to allow for fast rain water run-off that saved the concrete?

If nothing else works, I'd say that most of the red chaulk could be removed with soda blasting, which is the same as sand blasting, but they use baking soda as the grit. Here in Winnipeg, they have a free graffitti removal service for property owners that's included in the property tax they pay. It consists of one truck that pulls an air compressor trailer and goes around the city soda blasting graffitti off of walls and such.

I talked to the guy who does it when my building got "tagged", and he said the baking soda is hard enough to remove paint, but not hard enough to do any damage to the brick. Brick is very much softer than fully cured concrete, so it shouldn't do any damage to the broomed texture of the concrete.

I still see a very faint image on the brickwork where the tag was, and I expect I might be able to remove that with acid, but I haven't tried.

I'd let the slab cure for a few weeks, and then rent a sand blaster and use baking soda to remove the chaulk. The baking soda will get all over everything and it'll hang in the air for a few minutes. So, tell all your neighbors to close their windows so the baking soda doesn't drift into their houses. The next rain will wash the baking soda off of everything.

I see absolutely no reason why bleach would harm concrete any more than water would.

Bill: If the concrete wasn't damaged by the bleach already, and you rinsed the bleach off with WATER, and that water didn't do any harm either, then neither one did any harm to your concrete.

On Wed, 27 Aug 2014 21:58:28 -0700 (PDT),
wrote:

simple,Green scouring pad and a little water if it takes more than that then use a 120 grit Sandpaper these are stains they don't just magically disappear I've snapped lines that were bogus and tried to cleaning them off minutes later and they were extremely hard unless you have a little water and Green scouring pad it works like 400 grit sandpaper and if its been in there for a long time you may need to go a little more aggressive with sand paper yeah that takes some elbow grease it's a stain most times when you snap lines on a slab you want them to be permanentbecause they're usually being covered up by framing

Bah. Some chalk is more permanent than others. You have to pick the
correct one for the task. It may wash off easily or last longer; like,
say by walking on a concrete foundation ready for walls. YMMV

On Thu, 28 Aug 2014 13:25:56 -0700, Oren wrote:

On Wed, 27 Aug 2014 21:58:28 -0700 (PDT),
wrote:

simple,Green scouring pad and a little water if it takes more than
that then use a 120 grit Sandpaper these are stains they don't just
magically disappear I've snapped lines that were bogus and tried to
cleaning them off minutes later and they were extremely hard unless you
have a little water and Green scouring pad it works like 400 grit
sandpaper and if its been in there for a long time you may need to go a
little more aggressive with sand paper yeah that takes some elbow
grease it's a stain most times when you snap lines on a slab you want
them to be permanentbecause they're usually being covered up by framing

Bah. Some chalk is more permanent than others. You have to pick the
correct one for the task. It may wash off easily or last longer; like,
say by walking on a concrete foundation ready for walls. YMMV

Isn't chalk a calcium based compound, therefore a 'fast' wash with
muriatic acid [too fast to eat the concrete] remove it a bit better?

On Thu, 28 Aug 2014 14:01:05 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 13:25:56 -0700, Oren wrote:

On Wed, 27 Aug 2014 21:58:28 -0700 (PDT),
wrote:

simple,Green scouring pad and a little water if it takes more than
that then use a 120 grit Sandpaper these are stains they don't just
magically disappear I've snapped lines that were bogus and tried to
cleaning them off minutes later and they were extremely hard unless you
have a little water and Green scouring pad it works like 400 grit
sandpaper and if its been in there for a long time you may need to go a
little more aggressive with sand paper yeah that takes some elbow
grease it's a stain most times when you snap lines on a slab you want
them to be permanentbecause they're usually being covered up by framing

Bah. Some chalk is more permanent than others. You have to pick the
correct one for the task. It may wash off easily or last longer; like,
say by walking on a concrete foundation ready for walls. YMMV

Isn't chalk a calcium based compound, therefore a 'fast' wash with
muriatic acid [too fast to eat the concrete] remove it a bit better?

Dang if I know Robert. I've read some chalks last longer. Some less.
I'd read the label. What if it rains over the weekend after you popped
the line?

Robert:

Blackboard chaulk is calcium carbonate, which will dissolve in acid.

Red line marking chaulk is a red powder. Any red powder will do, but apparantly red line marking powder can be quite hard to remove.

Robert:

Blackboard chaulk is calcium carbonate, which will dissolve in acid.

Red line marking chaulk is a red powder. Any red powder will do, but apparantly the powder they use for red snapline marking can be quite hard to remove.

On Thu, 28 Aug 2014 14:01:05 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 13:25:56 -0700, Oren wrote:

On Wed, 27 Aug 2014 21:58:28 -0700 (PDT),
wrote:

simple,Green scouring pad and a little water if it takes more than
that then use a 120 grit Sandpaper these are stains they don't just
magically disappear I've snapped lines that were bogus and tried to
cleaning them off minutes later and they were extremely hard unless you
have a little water and Green scouring pad it works like 400 grit
sandpaper and if its been in there for a long time you may need to go a
little more aggressive with sand paper yeah that takes some elbow
grease it's a stain most times when you snap lines on a slab you want
them to be permanentbecause they're usually being covered up by framing

Bah. Some chalk is more permanent than others. You have to pick the
correct one for the task. It may wash off easily or last longer; like,
say by walking on a concrete foundation ready for walls. YMMV

Isn't chalk a calcium based compound, therefore a 'fast' wash with
muriatic acid [too fast to eat the concrete] remove it a bit better?
Coloured "chalk" isn't "shalk" I think some of it is more closely
related to laser printer toner!!!

On Thursday, August 28, 2014 8:14:59 PM UTC-4, wrote:
On Thu, 28 Aug 2014 14:01:05 -0700, RobertMacy

wrote:



On Thu, 28 Aug 2014 13:25:56 -0700, Oren wrote:



On Wed, 27 Aug 2014 21:58:28 -0700 (PDT),

wrote:



simple,Green scouring pad and a little water if it takes more than

that then use a 120 grit Sandpaper these are stains they don't just

magically disappear I've snapped lines that were bogus and tried to

cleaning them off minutes later and they were extremely hard unless you

have a little water and Green scouring pad it works like 400 grit

sandpaper and if its been in there for a long time you may need to go a

little more aggressive with sand paper yeah that takes some elbow

grease it's a stain most times when you snap lines on a slab you want

them to be permanentbecause they're usually being covered up by framing



Bah. Some chalk is more permanent than others. You have to pick the

correct one for the task. It may wash off easily or last longer; like,

say by walking on a concrete foundation ready for walls. YMMV



Isn't chalk a calcium based compound, therefore a 'fast' wash with

muriatic acid [too fast to eat the concrete] remove it a bit better?

Coloured "chalk" isn't "shalk" I think some of it is more closely

related to laser printer toner!!!

I'd try vinegar to dissolve the chalk followed by a quick pail of water to wash away the pigment.

Bill:

Find out who manufactured the red chaulk and then Google that manufacturer's name followed by the character string "red snap line chalk MSDS". The MSDS means "Material Safety Data Sheet".

Basically, by law, every manufacturer of any chemical product needs to supply an MSDS for every product they sell to whomever asks for one. So, most manufacturers just make them available online so that they don't have to bother mailing them out to people. The MSDS will tell doctors what's in the chemical a baby swallowed so that he knows what he and the baby are up against. But, it also gives that information to everyone else so that we know what the red powder in the chaulk is so that we might have a better idea on how to remove it.

I've looked at the MSDS sheets for two red snap line chaulks and both of them said that most of the chaulk was calcium carbonate (which is blackboard chaulk), but that each colour had a different pigment in it. In the case of red chaulk, the pigment was iron oxide, Fe2O3, which is basically rust. It's synthetic rust ground up into a very fine powder.

http://www.stanleytools.com/xhtml/li...halks-MSDS.pdf

If it's just rust, you can remove that red powder with hydrochloric acid. Muriatic acid is 26% hydrochloric acid, but you don't need such a strong acid here. You can buy 12 to 17% hydrochloric acid at any Janitorial Supply store. Just ask for a hydrochloric acid based toilet bowl cleaner. And, if you find that it's even too strong, just dilute it with water. When diluting acid, always pour the acid into the water, never pour water into acid.

But, your red powder might not be the same as Stanley's red powder. If you can get us an MSDS sheet for the red snap line chaulk you used, there's a much better chance that we'll know how to remove it if we know what it is.

On Thu, 28 Aug 2014 17:14:59 -0700, wrote:

...snip....
Coloured "chalk" isn't "shalk" I think some of it is more closely
related to laser printer toner!!!

I once spilled large drops of 'washable' red food coloring on the zipper
front of a pair of white dress trousers. You guessed it. Washable indeed!
Instant 'painting clothes'

On Thu, 28 Aug 2014 18:19:39 -0700, wrote:

...snip...

I still have some red chalk lines that have survived dozens of
pressure cleaning and 2 hurricanes. Red is pretty permanent.

They had to use that carcinogenic red food coloring somewhere!

On Fri, 29 Aug 2014 07:16:08 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 18:19:39 -0700, wrote:

...snip...

I still have some red chalk lines that have survived dozens of
pressure cleaning and 2 hurricanes. Red is pretty permanent.

They had to use that carcinogenic red food coloring somewhere!
Get som "barkeepers friend" - apply in a thick paste and cover to
keep it from drying out. Leave it for an hour or so and scrub with a
stiff bristle brush.

That said, a shotgun could prevent having to do it again. Shoot
anyone using red chalk. There is no excuse for using that crap when
blue works just as well and is a LOT easier to remove!!!

On Fri, 29 Aug 2014 06:55:42 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 17:14:59 -0700, wrote:

...snip....
Coloured "chalk" isn't "shalk" I think some of it is more closely
related to laser printer toner!!!

I once spilled large drops of 'washable' red food coloring on the zipper
front of a pair of white dress trousers. You guessed it. Washable indeed!
Instant 'painting clothes'
It WAS washable. Just wrong definition of washable. You can wash it
all you like, and it will not dissapear.

On Fri, 29 Aug 2014 08:18:06 -0700, wrote:

On Fri, 29 Aug 2014 07:16:08 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 18:19:39 -0700, wrote:

...snip...

I still have some red chalk lines that have survived dozens of
pressure cleaning and 2 hurricanes. Red is pretty permanent.

They had to use that carcinogenic red food coloring somewhere!

Seriously, the "red" seems to come from iron oxide according to the
MSDS so barkeepers friend, naval jelly or some other rust remover
might work.

maybe "Whink", a commerically available mild hyrdofluoric acid for
removing rust stains

but wear gloves!!!

On Thu, 28 Aug 2014 21:19:39 -0400, wrote:

I still have some red chalk lines that have survived dozens of
pressure cleaning and 2 hurricanes. Red is pretty permanent.

I dug out a planter between the house and the sidewalk for new soil.
Found some line that still had remnants of blue chalk from the house
construction.

On Fri, 29 Aug 2014 11:18:06 -0400, wrote:

On Fri, 29 Aug 2014 07:16:08 -0700, RobertMacy
wrote:

On Thu, 28 Aug 2014 18:19:39 -0700, wrote:

...snip...

I still have some red chalk lines that have survived dozens of
pressure cleaning and 2 hurricanes. Red is pretty permanent.

They had to use that carcinogenic red food coloring somewhere!

Seriously, the "red" seems to come from iron oxide according to the
MSDS so barkeepers friend, naval jelly or some other rust remover
might work.

What about rust in your naval?

replying to bill jensen, DD wrote:
bj wrote:

wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.
Any ideas appreciated.


I had red chalk stain in a kohler bathtub and tried everything to remove
it.
Then I read that the red chalk is made from rust properties or something
like that
so I used Ospho on the stain. It disappeared in seconds!!! I don't think
you will
be disappointed.


--

On Saturday, June 13, 2015 at 6:44:05 PM UTC-5, DD wrote:
replying to bill jensen, DD wrote:
bj wrote:

wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.
Any ideas appreciated.


I had red chalk stain in a kohler bathtub and tried everything to remove
it.
Then I read that the red chalk is made from rust properties or something
like that
so I used Ospho on the stain. It disappeared in seconds!!! I don't think
you will
be disappointed.

--

I believe the guy may have figured it out since he posted his question 4 years ago. ^_^

[8~{} Uncle Silly Monster

replying to bill jensen, Mr. Dan wrote:
bj wrote:

wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.
Any ideas appreciated.


I just found out today how to remove red chalk. Never been treated
concrete 4 months old. Framers used red chalk and we are going to seal for
the finish floor. The answer C L R. Calcium lime rust remover. I used
full strength with a disposable paint brush. Brushed it it for about 30
sec and it was gone! Rinsed with a wet rag and moved on.

--

Mr. Dan posted for all of us...



replying to bill jensen, Mr. Dan wrote:
bj wrote:

wow! Is there anything that will remove it? I've tried bleach,
cleanser and even Goof-off with no luck. I think a wire wheel may do
it, but it's a broom finish and i don't want to knock that off and leave
smooth area. fyi, the slab is just 3 days new so I've been holding off
on acids.
Any ideas appreciated.


I just found out today how to remove red chalk. Never been treated
concrete 4 months old. Framers used red chalk and we are going to seal for
the finish floor. The answer C L R. Calcium lime rust remover. I used
full strength with a disposable paint brush. Brushed it it for about 30
sec and it was gone! Rinsed with a wet rag and moved on.

--

Good post, I believe it was asked many times and no satisfactory answer was
ever given.

--
Tekkie

replying to Tekkie®, mowmow wrote:
I've had great luck with IRON OUT. I mixed a couple of cups of it into a
couple of gallons of warm water and used a stiff bristled brush on the end of
a broom handle (Menards) to pre-soak the area. I then sprinkled the Iron Out
directly on the chalk line (which had been there for two years now). After a
few minutes, I used the brush to work the wet powder a bit. I then used the
mix in the bucket to essentially rinse the area while not diluting it
excessively. I again added the powder directly to the areas where red
remained. After about an hour of repeating this process (an not much sweat)
the lines were completely gone in most areas and mostly gone in the rest. Wish
I would have done this years ago. I finished with a garden hose and
"wet-broomed" all residue off of the drive - the red will reappear
all-spread-out if you don't do this.

I'd be worried about CLR affecting the appearance of the concrete (concrete in
my area is heavy in limestone. Maybe Iron Out would have similar concerns (I'm
no chemist) but I can say with certainty that it had no ill effects on my
drive and I've used it to remove rust marks in several places in my very large
concrete drive. Almost TOO easy!

Finally, someone commented about people doing stupid things when they don't
hire professionals. I can tell you that even the best make mistakes, and that
is what happened in my case. I hired the best in the area, and one their
newbies used red chalk and we scolded for it. It will happen again to somebody
- even if they hire professionals.

https://www.homeownershub.com/img/dr
https://www.homeownershub.com/img/ds
https://www.homeownershub.com/img/dt
https://www.homeownershub.com/img/du
https://www.homeownershub.com/img/dv

replying to DD_BobK, Nicholas R Newton-Cahoon wrote:
Use a can of monster energy drink and scotch bright to remove lines

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