[Editor's Note: This article originally ran in the September 2013 issue of Classic Motorsports; for more updates on our 1967 Mini Cooper S, visit here.]
Applying paint is an art. And as we’ve found with our Mini Cooper S project, so is taking it off.
During most restorations, completely stripping the paint, primer and undercoating is a vital step in the process. If the foundation is good, yes, sometimes the car can retain its original paint.
Most restoration candidates, though, have signs of rust, poor paint preparation and accident damage. In these cases, doing the job correctly means stripping the entire car.
That said, the restorer needs to decide how far to go. Does just the top surface need to be stripped, or does the entire car need to be dismantled so the body can be dipped or media-blasted?
The answer depends on the restorer’s goals and budget as well as the car’s condition. Over the years, we have had great success by simply dry-stripping the top surfaces and then wire-brushing and painting the underside of the car. In these cases, we were doing rolling restorations on fundamentally solid vehicles.
Our poor little Mini Cooper S was a weaker starting point. It was already partially dismantled when we got it. Plus, it was rusty and had all the signs of bad paintwork. To top it off, it had obviously been in at least one accident.
The only right way to restore this car was to completely pull it apart, strip it down, and start over again. We had some work to do.
3 Methods for Removing Paint
Dry Stripping
- How it works: Just grab your DA sander, mount up some 80- or maybe 40-grit paper, and simply sand off the old paint.
- Pros: This is the easy way to remove paint. It doesn’t require much money or skill.
- Cons: It’s only truly effective on flat outer surfaces. Tackling the underside of the body or the insides of the engine compartment with this technique is nearly impossible. This method is also dirty, monotonous and time-consuming. If done incorrectly, it can also build up considerable heat, which will damage your metal panels.
Dipping
- How it works: The entire car is disassembled before the body is lowered into a chemical stripping agent. Thanks to the needed infrastructure, a commercial outfit needs to handle this process. Figure somewhere around $2000 to go this route.
- Pros: Dipping strips paint extremely thoroughly, and it spares the home restorer from dealing with the dust and mess associated with sanding.
- Cons: Since the chemical stripping is so thorough, every bit of primer and seam sealer disappears. Getting these materials back into crucial inner gaps can be a big challenge. Also, totally rinsing the chemical stripping agent can be difficult. In fact, our painter would rather not deal with a car that’s been dipped, as he can’t guarantee that chemical residue won’t create issues with his fresh paint.
Media Blasting
- How it works: A high-pressure stream of abrasive material is shot at a painted surface.
- Pros: If done right, media blasting does not damage metal, does not leave any residue, and is usually a little less expensive than dipping. You can also control the amount of body filler that’s removed, meaning you can leave the original paint, primer and sealer. In addition, the vehicle can be blasted without being disassembled.
- Cons: Soda won’t remove rust; a more abrasive media needs to be used to address this issue. Also, unless you really, really clean out the car afterward or use a special abrasive material, you will invariably find little piles of sand under your dash and in your trunk–sometimes for as long as you own the car.
The Right People for the Job
Our Mini was going to be one big project. We needed to strip the entire car from top to bottom, inside and out. Media blasting, we decided, was the right option for us. The question was, who could do it right?
We met Steve and Debby Sanguinetti of Blast Masters, Inc., at the Turkey Run, a hotrod show held at Daytona International Speedway. We liked them right away: We had a lot of the same friends, and they even knew the previous owner of our Mini. In fact, they had tried to buy the car, too.
They took the time to look over our car and said they could strip the entire thing for $1200 to $1400. That sounded easier than trying to do it ourselves with our Eastwood home equipment.
A couple of weeks later, we took the car to Blast Masters and found the shop to be very professional. It took them nearly two full days to complete the job, and they did beautiful work. Even better, they were patient with our photography and questions.
Alert the Media
The specific material used in media blasting can have a significant effect on the quality of the final result. Traditional sand blasting removes rust, but the process builds up a lot of heat–and that heat can lead to warped panels.
Baking soda is a gentler alternative. While sand uses friction to remove paint, the soft soda particles strip it away by exploding when they impact the bodywork. This process generates no heat, so it’s easier on the surface being stripped. It’s safe to use on fiberglass, rubber, chrome and even glass. Often times, the folks at Blast Masters will soda-blast a car’s outer surfaces while the glass, suspension, tires and engine are still in place.
Soda isn’t very effective on rust, though, and takes longer than sand to strip paint. This is why Blast Masters typically starts with soda and then switches to a more abrasive media for the underside of the car. However, the shop doesn’t use traditional silica sand, which is very dusty and creates highly toxic fumes. Instead, they use DuPont Starblast, a dark, fine staurolite sand that looks more like lava rock than traditional beach sand. It’s touted as more abrasive than silica but less prone to creating dust and heat.
Hitting Prime Time
From Blast Masters, our Mini went directly to The Body Werks, a high-end body shop located near the magazine office. Company owner Tom Prescott awaited our car’s arrival with his gun filled with PPG DP40 epoxy primer.
For around $600, he prepped our Mini’s body for the next step. First, he wiped down every inch of the car with DuPont’s Prep-Sol cleaner and degreaser. Then he primed the entire body, inside and out. He used nearly 2 gallons of primer to apply two thick coats.
When Our Story Continues
Our Mini’s body is now stripped and primed, but there’s still plenty more work to do. We need to order some replacement sheet metal from Mini Mania—we’ve already sourced a new driver-side door from Heritage Garage. In addition to putting the final touches on the drivetrain, we need to do lots of cutting and welding.
Sources
Blast Masters, Inc.
(561) 685-5378
theblastmasters.com
Media stripping
The Body Werks
(386) 672-2125
Priming
Heritage Garage
(949) 646-6404
heritagegarage.com
Used parts
Mini Mania
(800) 946-2642
minimania.com
Parts
Comments
Good aritcle but please stop propagating the myth that sand/media blasting causes heat that can warp the panels. I was very skeptical and did a test. I spot welded a thermocouple to the back side of a piece of sheet metal. I then blasted the spot on the opposite side of the metal. The area being sandblasted got cooler due to the expanding compressed air, which more that made up for any frictional heat. Panel warping is actually due to peening of the surface from the high velocity sand hitting it. Imagine thousands of tiny hammer blows.
Mike (Engineer, of course!)
Displaying 1-1 of 1 commentsView all comments on the CMS forums
You'll need to log in to post.
Update by Tim Suddard to the
