Environmentally Friendly Auto Refinishing

At Scandinavian Coachcraft all of our processes comply fully with all current environmental regulations.  As a state-of-the-art auto refinisher our technicians are highly trained to use sophisticated processes to restore your vehicle to a pristine like-new condition while maintaining high standards of environmental awareness.  Here’s an informative article detailing the use of eco-friendly water-based paints: ____________________________________________________________________________________________________________________________________________________________________________________________________________

Water-Based Car Paint – Waterborne Paints

We Sprayed It Ourselves And Can Attest-There’s No Need To Fear Waterborne  Paints

    By , Photography by     Car Craft, July,  2009
Water Based Paint Guide

People hate change, especially when the government forces it down their  throats. Perhaps one of the most notorious regulation changes faced by the automotive refinishing  industry in Southern California (but likely to be adopted nationwide eventually)  was the lowering of the legal limits of Volatile Organic Compounds (VOCs)  contained in products used to paint cars.

VOC is a very broad term used to label certain chemicals that evaporate very  easily from the liquids they were mixed in solution with. Lots of products emit  VOCs-stuff like paint, paint thinner, and gasoline all emit gases we often refer  to as fumes or vapors. VOCs aren’t just limited to paint products, though;  plastics release VOCs as they age. In fact, VOCs are even emitted in nature by  certain plants and trees. Nevertheless, these chemicals are believed to react  with gases in the atmosphere and contribute to pollution, smog, toxic death from  above, and all that doom and gloom stuff.

To lessen the amount of VOCs released into the atmosphere every year, the  California Air Resources Board set tighter regulations. Basecoat paint was one  item where a reformulation, switching to waterborne from solvent-based paint,  would allow refinishers to meet the new standards. The new standard became  waterborne paints, and manufacturers responded with new lines of automotive  paint.

We got the lowdown from Brian Ferre, custom painter and instructor at Los  Angeles Trade Technical Institute. He tells us waterborne paint is not a new  invention-it’s been around for more than a decade and has been in wide use in  Europe for many years. Most of today’s new cars are  sprayed with waterborne paint at the factory, too. It received an undeserved bad  reputation because of infamous problems that plagued a number of GM cars in the  late ’80s. The paint would peel off in sheets after a couple of years in the  sun. Ferre tells us that particular paint-lifting problem was due to  incompatibility between the paint and the primer. The paint itself was OK. Much  more development and testing have been done since then, and today’s waterborne  paint is at a quality level on par with traditional solvent paint.

Because this is an introduction to waterborne paint, we won’t delve into the  chemistry, but there are a few key points to remember that will make the process  easier. The only step affected by the switch to waterborne paint is the  basecoat. Though there are some waterborne primers, you’ll generally still use  traditional, solvent-based primer and clear. As a result, all current waterborne  paint is intended for a basecoat/clearcoat system. The colors dry to a dull,  satin finish, not a glossy one. You’ll need to clear it if you want it to shine.  Lastly, waterborne paint dries differently than solvent-based paint. It’s  critical to have enough airflow across the panel to allow the paint to dry fully  before spraying the clearcoat.

  • Water Based Paint Guide

    We found an abandoned Camaro  quarter-panel lying out behind our shop, cleaned it up, and prepped it for  paint. The e-coat primer was still in good shape except for a few spots where it  had chipped off and rust had started to form. We removed the rust with a wire  brush on an air drill rather than using a grinder because we wanted to remove as  little metal as possible. Once the rust was gone, we sprayed all the bare steel  with Dupli-Color etching primer we bought at our local parts store.
  • Water Based Paint Guide

    After spraying the recommended four  coats of primer and waiting 30 minutes, we scuffed the whole panel with 320-grit  sandpaper.
  • Water Based Paint Guide

    While there still is a little  solvent in waterborne paint, there is a lot of water, so you need to use a paint  gun designed to spray waterborne paint. The gun must have stainless innards that  will not rust or corrode. We used Eastwood’s new Concours HVLP gun and were  pleased with its quality material and design, awesome spray pattern, and at  about $160, its extremely affordable price.
  • Water Based Paint Guide

    Avoid the temptation to use regular  lacquer thinner to clean the gun. It does not react well to waterborne paint and  causes the paint to clump up rather than thin out. Guess how we know that. Clogs  are the last thing you want forming in your spray gun, so we cleaned everything  with rubbing alcohol. Special surface-prep cleaners are made to go with  waterborne paints. Be sure to buy some when you’re buying the paint.
  • Water Based Paint Guide

    We bought a quart of DuPont CroMax  in PX8, a Chrysler black, from Annex Autobody Supply in Los Angeles. Note that  waterborne paints will usually come in a plastic container instead of steel.  Because we bought such a small amount, our supplier just used a regular steel  can. The white stuff is called the controller and takes the place of activator  and thinner in regular solvent paint.
  • Water Based Paint Guide

    We added 10 percent controller to  the paint as specified by the mixing instructions on the data sheet. Using the  volume scale on the mixing cup, we poured 10 ounces of paint and added 1 ounce  of controller.
  • Water Based Paint Guide

    Because the paint doesn’t dry until  the water evaporates, waterborne paint tends to require longer drying times than  solvent paints. To speed the process, Ferre recommended we warm the part with an  infrared heat lamp for 15 minutes prior to spraying. We couldn’t find our heater  anywhere, so we skipped this step but did have a fan ready to blow across the  panel once we were done spraying. You can see why it would probably be better to  spray waterborne paints in a paint booth, especially if you were doing an entire  car. Our shop isn’t very clean, and we’d be blowing all kinds of junk onto our  freshly painted car.
  • Water Based Paint Guide

    Ferre likens the spray technique to  that of acrylic enamels some older painters may have used. “It goes on wet. You  always want to keep a wet edge.” Unlike urethane enamels, waterborne paints  aren’t supposed to be allowed flash time between coats. Start your second coat  as soon as you’re done with your first. Waterborne paints have a very high  solids count and cover completely in one coat with a second, lighter coat. You  may hear this described as one and a half coats. We’re sure that’s music to the  ears of the EPA-waterborne paint emits far fewer VOCs by volume than solvent  paint, plus you use less of it.
  • Water Based Paint Guide

    Once you’re done spraying, turn on  your fans and heaters. You can also buy handheld blowers that plug into your  shop’s air supply. If using a handheld one, hold it at a 45-degree angle to the  panel. Always direct airflow across the panel. If you point straight at it, you  can cause the paint to run.
  • Water Based Paint Guide

    As the paint dries, you’ll start to  see it change from a glossy appearance to a satin or matte finish.
  • Water Based Paint Guide

    Water-based paint dries differently  than solvent paint, too. Instead of getting sticky and tacky, waterborne paint  feels slimy and will come off in large blobs if you accidentally touch it. It  takes a little longer to dry-about half an hour for our quarter-panel. Once it’s  dry, you can begin spraying the clearcoat.
  • Water Based Paint Guide

    Proving that this is really  waterborne paint, it cleaned up with nothing but pure water. If you are going to  be doing this often, don’t just pour the stuff down the drain. There is a  recommended disposal procedure. As we mentioned earlier, we cleaned out the gun  with rubbing alcohol rather than lacquer thinner.

Conclusion After all the negative hype we’d heard about  waterborne paint, we were pleasantly surprised at how easy it was to use. It was  easy to spray and covered very well. We especially liked the easy cleanup and  near absence of toxic fumes filling up our shop. Trust us, give waterborne a  chance-you’ll like the stuff.

Pros And Cons Of Waterborne  Paint
Pros Cons
Excellent coverage More expensive
Uses less product Different spray procedure
Easy cleanup Different drying procedure
Saving the Earth one car at a time Need a dedicated spray gun
SOURCES
Annex Automotive Finishes Los Angeles Trade Technical Institute
Los Angeles, CA Los Angeles, CA
323/934-3177 213/763-7000
lattc.edu
DuPont Automotive Refinishes
pc.dupont.com The Eastwood Co
Pottstown, PA
800/343-9353
eastwoodco.com
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You can learn more and read the original article at Carcraft.

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