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-   -   Underbody treatment / Anti-rust coating for the car (https://www.team-bhp.com/forum/technical-stuff/9333-underbody-treatment-anti-rust-coating-car-24.html)

The dry state of Delhi also gets its fair share of monsoons - which is most likely going to arrive in a month. I've always had anti rust coating done for my cars - on my Hyundai, it made the cabin seriously quieter as well in addition to giving me protection from rust. Also, I recently got it done for my Endeavour along with exhaust pipe coating. Teflon is debatable. I'd say you can give that one a pass and instead go for ceramic coating, which even though a bit pricey, will provide much superior paint protection.

Delhi is not immune to monsoons and the heavy flooding is it?. Every monsoons there have been incidents of heavy water logging reported in Delhi. Its best to get the under body anti rust coating and skip the teflon coating as you are going for a new purchase.. I would suggest to go for 3M anti rust coating as they have a 5 yr warranty with annual inspections/top up.

Looking for a quick answer on 3M underbody protection (the 5 year warranty one)
I have never done underbody coating for any of my cars, and did not face any problems may be because Hyderabad is a dry area. So, I don't think rusting is an issue I have to worry about. Only reason for considering underbody protection for me is about noise reduction. Can anyone tell me if this really helps in any road noise reduction or it's just a marketing gimmick?

Hey Adimicra,

My personal take on Under-body coating:
- Its definitely good to prevent rust. Rusting is more when there is a lot of mud stuck to the under-body and this holds the water for a longer duration which helps in rusting. The 3M product creates a thick layer and doesn't allow the mud to come in contact with metal under-body

- Noise reduction: I didn't see any difference. After all its just paint.

-how to get it done: Here comes the interesting part. DON'T go to any one who advertises this service including 3M car care workshops. You'll get ripped. Instead buy the 3M under-body paint from the local hardware/auto stores. 500 ML of paint and about 700 ML of thinner (xylene based) would cost you around 500-600. Now take the car to any of those local cleaners who have the big hydraulic jack. Most of them also apply these coatings. Have the under-body thoroughly washed and dried. Get a good layer put on the underbody, bumper to bumper including wheel wells, shocks, silencer (it doesn't burn) etc. This should cost you around 700-1000 depending on city/location. Do not start driving immediately and let it dry for about an hour for best results.

This is a cost effective method, you get the original products as you buy them yourself. I did it in Asansol for my City iDtec. Total cost was INR1300 against 5000-6000 quoted by showrooms. The warranty is gimmick. They do just touch-ups which is mostly not required as nothing happens to this for at-least 2-3 years of driving on moderate roads. If required, get another coating done after 2 years. Still you save money.

Hope this helps.

^^
Thanks for your detailed response. I am not convinced that this is needed. As I mentioned, I have been driving for 15 years and have never done this treatment on my cars. My Honda Jazz is 9+ years old and I don't see any signs of rusting. Also, many cars have some sort of underbody coating already done from factory. For example, VW provides anti-corrosion warranty (for 3 years I think) on all of their cars. I think it may be needed in high humidity/coastal regions. Hyderabad has a very dry climate.

Just a suggestion, a recent video on testing various anti rust underbody coatings shows that waxy type coatings would be ideal for Indian conditions. The rubber and tar based ones if not done with proper prep can also lead to rust formation by trapping moisture underneath. The water based ones are also good but need to be reapplied every 6months to a year.
Wax based ones would last atleast 2 years. Used transmission oil or thick engine oil is also a good cheap alternative

Hi,

Getting an Innova Crysta, dealer is offering Wurth underbody coating at 4500. Is it worth it?
Also contemplating on getting a ceramic coating.

Please advise.

Usually the new cars come with anti rust coating from factory. I got this from FIAT and Honda service advisor. So ideally for 2 years you don't need anti rust coating in new cars.

Better get some other accessories or cash discount.

Bad bad idea, besides all the muck that would stick and form over it, you also endanger lives of people travelling on two wheels as in monsoons all this oil would form a slick film on roads and cause a lot of accidents.
Please avoid doing this and don't encourage the same as well.

The best time to do underchasis coating is when it's new and surface is still fresh and not contaminated with dirt and debris.
I have always done the same for all my cars and I think it's a little cost to pay then fight with corrosion if it occurs.

Hello, I have recently bought a 2012 Honda City.

I understand the logic behind getting it done on a brand new car, but would it help me in anyway or is it an unnecessary expense?

Also, any brands should I go for if I get a go-ahead for the coating from you guys?

In ideal scenario yes, a brand new car with fresh coat of underbody coating will help if you are living in humid or coastal or possibility of wading through slush.

Since this car is ~8 years old, you can still go ahead, but there is no need to go for a costly wallet breaking brands. During your next pressure wash or service check the underbody for rust or corrosion. If you see corrosion or rusts (not superficial, but eating through) then first go for Rust Converter or primer and then coat with protective paint. This is important step for a old car underbody protection.

Underbody paints compositions have many options. Bitumen based, Rubber based etc.

Thank You Sir for the information, but as it turns out, the previous owner had already applied underbody antirust spray and also the same in the engine bay (cowl area), which according to a detailer should suffice for another couple of years. So one less expense to make. Regards.

I don't get it, when will BHPians realize that the Underbody treatment / Anti-rust coating is NOT needed. Even if you are living in a coastal area it is NOT needed, can't stop the ravages of nature.

A perfect protective coat is already provided by the car manufacturer and it lasts for a minimum 10 years! I can't believe people are applying something on top of that which certainly won't adhere firmly as the service providers do not and cannot prep the surface before applying the coat.

Furthermore, if you still want to do it, understand this ... The car's underbody is not flat, there are crevices, nooks and corners, and cables running around and plenty of dirt/mud accumulated (this is acceptable and normal). Prior to applying a coat, it is impossible to clean these areas thoroughly so applying a coat on top of this is JUGAAD

Wake up guys, stop wasting your money and also smudging your car with this ugly coat.
Someone also said it made the cabin "seriously quiet" ... :uncontrol

Is there any underbody coating (including the wheel wells)which will reduce road noise to some extent? Adding dampening floor mats might reduce it further. I am not talking about the ambient sounds like traffic, horns etc which are actually required to better navigate the car in traffic. I mean the noise on highways which comes from the tyres and varying road surfaces, potholes etc. I am not worried about the engine noise as I actually like the sporty growl of my sweet 2.4 i vtec:D

Better option is to replace your tyres. Try Michelin Primacy’s. Used them on my Vento and, for around 75% of their life, they are super silent.