Design & Technology

Coating the future with water-based paints November 7th, 2007

Kyehwan RohBy Kyehwan Roh
Assistant Manager
Environmental Management Team

Environment-friendly cars touting buzzword such as “Eco,” “Green,” and “Blue’ have been the rave at recent motor shows. This trend is a direct reflection of the efforts being made by automakers around the globe to reduce air pollution by curbing carbon dioxide (CO2) emissions from vehicles.

This has also been a key mission of Kia Motors. On top of developing eco-friendly cars, we have continued to work on reducing various pollutants generated during the manufacturing process. One of our key efforts is replacing oil-based paints with water-based paints in the coating process of vehicles manufactured in Hwasung (Korea), Slovakia and China plants.

The basic automotive coating process consists of three steps: electrodeposition, surface and top coating (base, clear). Oil-based paint is typically used for surface and top coating. But this is not the case anymore. Following the electrodeposition painting process, water-based paint is used for surface and top coating (base). Oil-based paint is used only in the last clear coating process.

Painting process

By using water-based paint instead of oil-based paint, we cut volatile organic compounds (VOC) by 70% (120g/㎡→35g/㎡). And unlike traditional coating which requires three drying processes, water-based paint requires only two, thereby reducing greenhouse gas (CO2) emissions by 15%.

Of course, this eco-friendly process also has its share of problems. Due to its property of dissolving well in water, an increase in waste water treatment costs and COD (Chemical Oxygen Demand) is inevitable with water-based point. Nevertheless, we are tirelessly seeking ways to resolve these issues.

Some people worry whether using water-based paint would make the coating job more difficult. Others are concerned that the paint dissolves in water or that water may seep into the paint after the coating process. But there is no need to worry. Water-based paint is easy to work with and once the paint dries, its waterproof membrane capability, very similar to oil-based paint, helps to protect the paint job from water.

Kia Motors plans to gradually expand the use of water-based paint to all models in our line-up as part of our commitment to protecting the environment through reduction of VOC and CO2 emissions.

  • Jon

    With eco-friendly production process becoming more important in today’s global market place, it’s good to see Kia already has plans along these lines.

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  • Greg

    I know this has nothing to do with water-based paints, but:
    IRVINE, Calif., November 6, 2007 – Kia Motors America (KMA) today announced it will give its new midsize SUV the moniker of “Borrego” when it debuts in January at the Detroit Auto Show. The Kia Borrego will be manufactured in Korea and go on sale in North America in late spring or early summer of 2008 as a 2009 model.

    Built with body-on-frame construction incorporating the latest in NVH engineering philosophy, Borrego will be Kia’s newest addition to its well-rounded full-line of vehicles that continually provide value, safety and a steadfast 10-year/100,000-mile warranty to consumers. Borrego will be available with either a V6 engine or the company’s first V8 offering, which will also boast Kia’s largest towing capacity to date.

  • Boris

    I’m very happy to see my fav auto brand is concerned about the environment. And I’m waiting for your RioHybrid as well, and hope that all of your vehicals will soon be eco-friendly.

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  • Boris

    Is the Borrego going to be coated with water based paints, Roh?

  • Greg

    Kia is pushing for Teir2Bin5 diesels ASAP! Kia Borrego interior shots in January!

  • Hello Boris,
    Sorry for my late response.
    Yes, the Borrego is going to be coated with water based paints, too.

  • Boris

    cool. We would like to see you at least once on another KIA blog , Roh

  • sonty

    hi, this is only somehow related to the paint issue and more to the rust protection methods, but I’ll ask it anyway.
    I got into a discussion with a friend about different car manufacturers and the practice of having a galvanized body shell of their cars. he thinks this is a rather expensive procedure and since it’s not mentioned anywhere in the kia documentation it means that kia models don’t have a galvanized body shell. I on the other hand believe all steel body parts go through some rust protection procedure, one of which might be the galvanization process.
    could you please clear up this issue for us by detailing the steps taken in surfuce preparation before the electrodeposition step?
    thanks a lot.

  • Joe

    Having worked at a paint store, I am familiar with the properties of oil and water based coatings. Oil based coatings are more rigid and brittle, and less prone to chipping than latex (waterborne) coatings. Oil bases also penetrate substrates while latex coats the substrate (e.g. oil-bases will attempt to penetrate the electrodeposition layer for greater adhesion). The key feature of latex is its elastomeric nature (elasticity). It can expand and contract with changing temperature which is necessary for a house, not so for a vehicle. Though one plus would be that when the clear coat eventually wears off, there will be no oxidation of the latex paint (oil-bases oxidate) and no “white scarred” look. However, the bare coating will be much more prone to damage from hail and abrasives.

  • Phil Barry

    I have just bought a 2009 Kia Soul in the UK, whilst reading owner’s reviews I noticed owners in the US were reporting issues with the paint chipping too easily, I was wondering if this was due to the change to water based paints (although Joes comments would suggest the opposite ie oil based is more prone to chipping ).
    Also the US Kia Soul is available in different colours to the UK, are they painted in the same way in the same factory or were some Kia Souls painted with oil based paint and later ones with water based ?

  • ron eccles

    Hi. My Soul is 6 months old and full of stone chips, only done 5000 miles. Two pieces of paint flaked off the rear door today. Is this a problem with the electro’ coating or the water based paint??