[Tarmac Raiders]

Hi,

I have recently purchased a new car and I always park it in the basement of my society. Yesterday the ceiling of my parking slot started leaking and there was a white mark on my car. On investigating, it turns out the mark is caused by Calcium Hydroxide. On enquiring with the supervisor, he mentioned that this has happened earlier with other cars and I will have to get it repainted.

I wanted to check, is there any way to fix it without having to repaint. I am not keen to get it repainted as this is just a 2 month old car and the paint is still original.





Thanks

[mvadg]

Originally Posted by Tarmac Raiders

Hi,

Thanks

Lime or calcium hydroxide is highly reactive. It is an alkali but in terms of damage it is like an acid. I think it will damage the paint and the metal below. Exposed metal will start to get affected by moisture and other agents which will continue the corrosion started by the calcium hydroxide. If wax has protected the paint, you can wash it off with water, examine the paint and decide what course of action you want to take. You must cover your car if there are any more chances of the chemical dripping on your car.

[Tarmac Raiders]

Thanks! I have moved the car but will have to wait till the lockdown ends to get it repaired. Sharing the images below.

[ATTACH=WhatsApp Image 20200329 at 10.35.14 AM.jpeg][/ATTACH]

[Nithesh_M]

Some people tried to remove it with Vinegar.
But Vinegar aka acetic acid might damage clear coat on the paint or in some cases the paint itself on its own. It is a risky experiment so if you decide to take that risk make sure to keep paint sealant/wax/polish handy. You'll need to apply it even if you don't see any acetic acid damage.

https://chemistry.stackexchange.com/...harm-car-paint

[indian21r]

Sorry to hear you experiencing this with your new car.

I had experienced this with my car a few years back. I was told there is nothing that can be done. So we got the panels painted from the Authorized service center.

[vamsy]

Yup, the same thing happened to my polo as well. It went away over a period of time with me persistently cleaning it with car polish. Since the paint quality of VW is very good, I could not see a visible deterioration of that area because of my rubbing for a long time. I have to appreciate the paint quality of VW.

[itwasntme]

Originally Posted by Tarmac Raiders

I wanted to check, is there any way to fix it without having to repaint. I am not keen to get it repainted as this is just a 2 month old car and the paint is still original.

Take it to a reputed detailer in BLR like Feynlabs or Ultimate Detailerz or 3M and get it checked when the lockdown is over. Dark colours can be permanently damaged compared to lighter ones.

[Rshrey22]

Just take some lemon juice on a cloth and rub off the residue.

[saisailendra]

This happened to our Jetta as well. It was raining heavily and the water seeped through the balcony floor below which our cars are parked. The water seeped through the floor of balcony/ceiling of parking and ruined the trunk, rear bumper, rear left fender of the car. Dad took the car to a 3M centre and they were sure they can remove it. But they quoted 7k or 8k (was a long time ago), for this and a complete car polish.

My dad checked online and had tried scrubbing the affected part with Vinegar. I wasn't home at the time. Apparantly the vinegar did remove the marks, but his scrubbing methods which were a bit too harsh, and this resulted in scratches (hairline) where he scrubbed too hard.

And the Vinegar didn't effect the clearcoat or the paint in anyway. It's been about a year and the paint is fine.

In a nutshell, vinegar will do the job. Be gentle and don't scrub too hard. Rinse off the vinegar once you're done with it, to prevent any adverse effects on clearcoat.

[GTO]

Mod Note: Thread moved to Technical Stuff!

[sarang.vaidya]

Originally Posted by Tarmac Raiders

Thanks! I have moved the car but will have to wait till the lockdown ends to get it repaired. Sharing the images below.

[ATTACH=WhatsApp Image 20200329 at 10.35.14 AM.jpeg]Attachment 1985434[/ATTACH]

I was able to remove some tough hard water marks using a tooth brush and Harpic. Just rub very lightly and the marks dispensary quickly. You can try to dilute the harpic in 1:1 ration and use it on the paint. Looking at the mark on your vehicle, i think this should work for you as well.
I have done it long back and i don't see any damage to the paint or the clear coat as of now. Its a pretty old car on which i had tried this. You can always give it a try at your own risk before going in for a complete repaint or spending 6-8k with 3M guys.
Post you do this, use a good quality polish/wax to protect the area.

[audioholic]

Originally Posted by saisailendra

And the Vinegar didn't effect the clearcoat or the paint in anyway. It's been about a year and the paint is fine.

In a nutshell, vinegar will do the job. Be gentle and don't scrub too hard. Rinse off the vinegar once you're done with it, to prevent any adverse effects on clearcoat.

While the use of any product is to be done at one's own risk, but I would like to add that when we use such products like Vinegar or similar items, it would also work better if you soak the affected area with the solution until the solution actually reacts with the damage. Too much soaking will affect the paint, and too less will just not work. What we are trying to do in this case is to have an acid-base reaction which will not happen instantly. Neither will be the damage to the clearcoat. So gradual trials with more and more dwell time will work better than the effort of scrubbing. One can use an earbud or some paint brush to limit the soaking to the affected area only and not the surrounding paint.

[libranof1987]

Originally Posted by Nithesh_M

Some people tried to remove it with Vinegar.

I spotted these stains on the roof + front windshield of my car and immediately wiped them off with a 1:1 mixture of vinegar and water. Luckily, I noticed this within a few hours of the leakage causing them and while it was still happening so the stains were still wet and could be wiped off with a moderate effort of rubbing. No damage to the paint/scratch marks thankfully.

Originally Posted by sarang.vaidya

I was able to remove some tough hard water marks using a tooth brush and Harpic.

They don't recommend harpic for anything but the toilet pot; using it for the paint is quite gutsy!

[abhishek46]

Originally Posted by sarang.vaidya

I was able to remove some tough hard water marks using a tooth brush and Harpic. Just rub very lightly and the marks dispensary quickly. You can try to dilute the harpic in 1:1 ration and use it on the paint. Looking at the mark on your vehicle, i think this should work for you as well.
I have done it long back and i don't see any damage to the paint or the clear coat as of now. Its a pretty old car on which i had tried this. You can always give it a try at your own risk before going in for a complete repaint or spending 6-8k with 3M guys.
Post you do this, use a good quality polish/wax to protect the area.

Be very careful while using harpic. It is highly corrosive.
It is best to use products which are much less corrosive.
Vinegar or any such weak acids OR rubbing compound are a safe bet.

My 'white' car had received some ugly kumkum (turmeric) marks on all the body panels.
A little scrubbing with rubbing compound, and then 1 hour of good sunlight was enough to remove the stain completely.

[technofunky]

Originally Posted by Tarmac Raiders

Thanks! I have moved the car but will have to wait till the lockdown ends to get it repaired. Sharing the images below.

[ATTACH=WhatsApp Image 20200329 at 10.35.14 AM.jpeg]Attachment 1985434[/ATTACH]

Sorry to bump this old topic, but I am in a similar situation, OP were you able to remove these stains with anything ?