Master Blaster
Plastic Media Blasting: Proper Preparation for a Quality Paint Job
By Rob Hallstrom
Photography: Robert Hallstrom
A quality paint job is only as good as its preparation. Even the world's most reputable painter can't hide years of blemishes and rust, regardless of how many coats of paint are applied. Without the proper preparation, the vehicle's paint will eventually chip, flake, peel and...need we say more?
The solution to these problems is simple: Rid the body of its old paint. This will not only make it easier to assess the body for bondo, rust and other things, but provide an ideal surface for the paint to be applied.
As far as a method, there's really only a few acceptable ways to remove your VW's paint. One includes a DA sander (and about a gazillion sanding pads), while the other requires toxic chemicals, such as a stripping agent. Though these methods may be used, the most effective way of ridding paint from your VW is through dry stripping.
While commonly referred to as sandblasting, there are other forms of dry stripping which are more efficient, such as Plastic Media Blasting (PMB).
Unlike traditional sandblasting, where hard and abrasive silica sand is propelled at high (60-100psi) pressure, PMB employs softer recyclable plastic particles at low pressures (20-40psi). These tiny plastic particles actually shatter the coating and disperse it, while having no effect to the underlining surface. The results are quite surprising, leaving a bare metal finish, free of all paint and primer and without gouging, scraping, pitting or warping (because of excessive dwell).
These particles are available in a variety of performance/aggression ranges (from talcum powder-like fineness to the size of No. 12 bird shot) to meet the requirements of specific automobile substrates and finishes.
PMB is also a more refined, discriminating processes than sandblasting. Performed within a specially modified booth (similar to a traditional spray booth), the operator holds the power nozzle as close as 6 inches from the surface being treated (as opposed to 3-4 feet for sandblasting).
This not only allows the operator to better target and pinpoint special intricate areas, but have increased overall versatility.
We recently contacted Blastech, a local dry stripping company in Orange, Calif., and witnessed the procedure firsthand. Within a few hours, our donor car, a 1967 Bug, was completely stripped of all its paint (we counted at least five different layers and almost as many colors), as well as all primer.
As told, the bare finish was impeccably clean and void of any surface damage from the blasting. Needless to say, we were quite pleased with the end result.
Blastech evaluates each job to determine the correct media for the application. It is also the company's practice to use the lowest pressure consistent with efficient removal, further protecting the substrate. Moreover, the company is equipped to handle jobs of various sizes, both big and small and has no minimum charge.
With this in mind, if you're considering painting your VW, consider PMB, like us, you'll be happy you did.
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Within a few hours, our 1967 Bug was completely stripped of all its paint and primer.
The blasting operator holds the power nozzle as close as 6 inches from the surface allowing precise targeting.
Plastic media is available in a variety of performance/aggression ranges (from talcum powder-like fineness to the size of No. 12 bird shot) to meet the requirements of specific automobile substrates and finishes.
The before and after pictures illustrate the difference of only a few hours inside the media blasting booth.
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