Underbody Coating

UNDERBODY COATING

INTRODUCTION

As we know especially in INDIA there are major six season . The extreme and harsh seasons are hot summer ,winter and monsoon seasons.So not only the vechile are exposed to it but human body too are exposed to these harsh climate. Due to which our skin become dry,rough,itchy and our skin gets tonned.so in order to protect it from these harsh climate we need to apply some oil ,ointment basically to create an addtional protective layer against these harsh climate.So same thing happens with our vechile on road ,when it is exposed to dust,muddy ,humid climate ,rain and pebbles so in order to protect them too we need to apply some paint or coat on the body of our vechile.

Underbody coating is usually a thick film which is applied uniformly throughout the undercairrage,chasis,frame inner panel or may be the fender of our vechile .Underbody coating is also helpful where in human eye are not accessible such as crack or the holes.Underbody coating is used to protect the vechile from harsh climate such as humid and rainy weather .If coat is not done then it is easily gets oxidises because as vechile parts are made of steels and irons.Exposure to rain wtaer is mostly the common cause for rusting.It is also helpful in snowy areas where snow gets deposited on our vechile ,if coat is done it is easy to slide them off.Underbody enhances the service life of our vechile.

In this competitive market the manufacturing companies are cutting down their prices by not coating twice or thrice so as to reduce the price of vechile to some extent,due to which the underbody starts rusting after few years.People after taking new car they do spend much money on changing mobil,doing sevicing on time and applying wrap on over body of the car but they forget to pay attention undercairrage of vechile which is highly prone to dust,patholes ,pebbles,rock and etc resulting in dents and rusting.

THERE ARE BASICALLY TWO METHODS EMPLOYED IN UNDERCOATING

1.MANUAL METHOD-In this method the car body is raise to suitable height and then skilled person sprays the paint on the body and undercairrage.But nowadys it is done by thr robot for high accuracy and precision.

2.LIQUID BATH-In this method the body frame or chasis is dipped inside the liquid with certain angle so the paint is applied uniformly and if excess coat is deposited ,it can easily slide off by tilting at certain angle.

WIDELY USED TECHNIQUE IS BY ELECTRODEPOSITION PROCESS

THE VARIOUS STEPS INVOLVED ARE-

PREHEAT TREATMENT-All the excess metals are removed if any ,then all the parts are cleaned throughly to remove any welding residues by degreasing ,phospating and cleaning .A phosphate treatment basically provide inert layer to the metal making it corrosion resistance.The degreasing solution component include caustic soda and sodium carbonate.

ELECTRODEPOSITION(ED)-This steps include dipping of automobile in ED tank which comprises of coating solution then passing an electric current through the body.The unique part of it that where spray do not reaches to areas such as holes and cracks by electrodeposition it can be done.During its operation a mixture of binder resin all are feed into the tank.The solution in ED tank comprises 80%-90% of deionised water and 10%-20% of paint solids.The resin provides the durablity and toughness to the automobile part and the pigment gives the colour to the automobile parts.After the ED coatings the automobile parts are taken into the oven at 160 degree celcius for about 10 minutes for curing time.Very common problem in ED coating is that water droplets are left on the surfaces .If any water droplets or any defects are there then it must be removed by sanding.So to elimintae these problems watwer must be deionised properly.

RUSTPROOF MATERIALS:SEALERS/PVC -The third step is that we need to apply seam sealing to door sections and the rocker sections.PVC are generally applied to the hood parts which are prone to chpping .Basically these third steps increases the resistance to chipping actions.

PRIMER-Primers may in the form of powder,solvent or water brone.In this steps the primer fill the small imperfection such as scratch as result of sanding in previos steps so primer removes all the minor imperfections.It increases the paint durablity.It also make corrosion resistance and make adhesion stronger .It is usually done in three stages interior coating then exterior coating and finally taken into oven.It must be noted down that primer matches the basecoat so to get out aesthetic look.

TOPCOAT -It consists of two layers coat basecoat and clearcoat.

1.BASECOAT-It consist of colouring pigment.Basic function is to give colour to the automobile .For facts there more than 40,000 basecoat known till date.

2.CLEARCOAT-Finalmost and the last one coating done on automobile.This is only resposible for glossy finish looks.This type of coat prevents the car from fading due to UV's sunrays.

PREPARATIONS BEFORE APPLYING PAINT

1.Vechile is lifted to suitable height.

2.Car body is washed with high velocity nozzle.

3.Car body is then dried with compressed air.

4.Area where paint is to be applied is painted while others part are masked or covered such as engines and exhaust pipe.

5.Piant is througly stirred for a minute in a can and then the can is connected to nozzle gun.

6.At room temperature paint is sprayed at a optimum distance.

7.Leave it for some time to let it dry.

8.Now it is ready to go for second coat if needed go for third coat in order to obtain more thickness.

TYPES OF UNDERBODY COATING

1.RUBBERIZED UNDERBODY COATING

• It is very easy and safe process to apply.
• It provides well cushioning against dust ,moisture,scratches and dents.
• It gives as soft as rubber surface finish.
• This paint can be easily removed with undercoating removal spray.
• This paint can also be applied to body cover.

2.ASPHALT BASED UNDERBODY COATING

• It is widely used for large and ligt commercial vechile such as truck,pickup van and also for heavy machine.
• It is also mixed with rubberized coating so to make it sound proof from outside noises on road.
• It fights against chips ,pebbles and moisture.
• It needs more cure time.
• This is mainly used for underciarrage coating.

3.POLYURETHANE UNDERBODY COATING

• Before applying this paint some sort of preperation is needed like cleaning and degreasing.
• It is easier to apply as it is contained in a container.
• It is a quicker process to apply the paint.
• This coating mainly prevents from salt and moisture formation which aid in rusting.
• Before applying this type of coating an etching primer is applied to base metal.
• It works well by filling any types of holes or cracks by displacing the salt or moisture so as not to cause rusting.

4.WAX OR PARAFFIN BASED UNDERBODY COATING

• This is the quickest options avilable in the market .
• secondly it is cheapest one in the market.
• This type of coating usually do not last for longer duration.
• This type of coating goes away very soon due to wear and tear.
• This coating usually do not harden.
• This type of coating barely provide protection to the base metal.

ADVANTAGES OF UNDERBODY COATING

1.FIGHTS AGAINST RUST-If our vechile is more prone to humid climate especially near coastal areas then there is sure sort of rust formation so coating does help in preventing from rusting.Even if the coatings wear out ,it helps in keeping rusting at bay for some period of time.

2.ABSORBS NOISE-Applying very thick coating or more than two coating does no harm to our vechile ,but it act as an additonal protective shield or we can say strong barrier between the outside noise and the car cabin there by allowing no outside noise .As the coatings is done of rubberrized material so rubber has the properties to absorb the noises there by giving soundproof driving experience.

3.EXTEND'S CAR LIFE-Coating not only prevents the undercairrage from rusting but also prevents the vital components such as engine ,transmission and the exhaust pipe as well.Sometimes the rusting can cause harm to the metal wire ,so it alos prevents them too from rusting there by increasing the car's life .

4.APPLIED TO DAMAGED AREAS-Over due course of time our vechile develops cuts,scratches and dents while driving on road due to the pebbles,rocks and gravel present on the road.In this case Polyurethane or wax based coating can be done to prevents from dents or crack .But generally wax based coating are applied because it works well by seeping down into the cavities ,crack or the holes.

5.SELF APPLIED- Coating is not difficult task ,if we do have some basics skill about the car's maintainance then surely we can apply it,generally for rustproofing some professional one worker is needed.For the same task if we go to the dealer then i am pretty much sure they are going to charge hefty amount of money ,if our money is constrained to some particular amount then we can be ready to paint by ourselves.But do remember we are sure going to make mess of it ,but we need to keep patient because we are not going to coat the upper body but the undercairrage of vechile so dont worry about the finishing part.

6.REINFORCEMENT- Coating more than two coat usually gives a better result .Coating on top of the coat do increases the weight of the car but laso increases the strength of the sheet metal body and the most importantly the stablity of the car also going to increase.

7.INSULATION-Coating not only hepls in keeping rusting at bay ,but it also provide protection from the exterme hot temperatures in summer season when sun rays are high.What happens is that the coating reflects back the sun rays into the environment there by making favourable environment in the car's cabin.

8.OTHER PERKS-We have many types of coating avilable in the market so we can get it done whichever we feels good for our car.Some companies give warranty on the coatings which again can be a big savings and worry free for our mind as well as to our pocket.

DISADVANTAGES OF UNDERBODY COATING

1.WORKS BEST ON NEW CAR-If we do coating on used vechile then there would be much money spended than the actual price of the car.So to start coating on used car we need some preperations like we have to remove all the dirts or the residue , if we don't do the cleaning then there will be some serious problem of rusting can start.So it is advised, for better results coating should be done on new cars for superior protection.

2.ADDS WEIGHT TO THE CAR-Applying more than two coat can be good and bad at the same time but both has its own benefits and demerits.If the weight of the car increases then surely there will be high impact on the engine performance as a result fuel efficiency will go down.

3.REAPPLIED AFTER EVERY 2-3 YEARS-Hardly the coatings stays for years ,the warranty given by the coatings companies are also for very short duration so for better reults coating must be done after every 2-3 years.For regions like snowy and coastal areas we need to apply every 2-3 years.

4.THIRD PARTY UNDERCOATING SERVICE MAY VOID VECHILE'S WARRANTY-Many of cars now comes with already having rustproofing and coatings done inbuilt.If we do coatings for used vechiles then its fine because it is going to increase the life of vechile.But if we do it for a brand new cars then we cannot avail the rustproof warranty benefits due to strict terms and conditions.

5.LESS EFFECTIVE IF CORROSION ALREADY PRESENT-If rusting has progressed so there is no use of undercoating.As we all know of the fact that coating do help in protecting the corrosion but it is not going to protect if we do undercoat on the rusted part it might look good but would not serve the actual purpose.We agree that undercoating inhibits rusting,but we need to clean the surfaces first to protect it from further damge.

6.NOT IMPERVIOUS TO DAMAGE-It is not what we always indian people feel that now we have done the coatings so nothing is going to happen to our cars .If we drive the cars on dirty ,peebles,gravels types of road then there is much chances that we might develops cracks and dents within a months.It tottaly depends upon us how we drive and to what roads or climate are we exposed to it ,so based on it we can minimise the damage.

NEED OF UNDERCOATING

• PROTECTS THE VITAL COMPONENT
• INCREASES THE SHELF LIFE OF CAR
• PROTECTS THE CAR FROM RUST AND DENTS
• KEEPS THE VALUE OF THE CAR
• REDUCES NVH(NOISE VIBRATIONS AND HARSHNESS ) LEVEL
• PREVENTS PAINT CHIPPING
• PREVENT FROM EXTERNAL INFLUENCES(ROAD DEBRIS,HUMIDITY ,SNOWY, RAINS )
• TO GIVE AESTHETIC LOOK TO THE CAR