Following a first-time restorer through the sand-blasting process
Story and photos by John Gunnell
If we talk about Jeff Moll “cleaning the metal” when he restored his ’67 Camaro, we don’t mean giving the car a bubble bath. Clean metal is essentially metal that is clear of dirt, old paint or other contaminants, leaving it completely bare.
Restorers want to save as much of the factory original sheet metal as possible. This means cleaning off all of the rust and corrosion. However, if the oxidation has reached a certain point, the metal will be rusted through and can’t be saved. In that case, the bad spots must be cut out and replaced with good metal. That involves sheet metal fabrication work and bodywork, which are not the topic of discussion here. Here, we are interested in cleaning the metal to determine what can be saved, and keeping that metal clean until the car is repainted.
Moll took the do-it-yourself route in removing the paint from his 1967 Camaro. He removed most of the blue paint on the car by hand using an orbital sander to strip the old finish, moving slowly and doing one section of the car at a time. This method was best for Moll, because he was restoring the car in his home garage and had a limited amount of space and equipment.
However, sanding paint off a vehicle in this manner can be laborious and dirty. Moll took his time and kept at it throughout the summer and fall as he stripped down other parts of the car. He discovered rust in places where it is typically found on first-generation Camaros, such as the edges of the rear wheel housings, the floor pans and the underside of the trunk floor. Fortunately, none of it was too severe, but new rear quarter panels were necessary. He also discovered rust around the side windows that he couldn’t get at with his orbital sander.
Since the Camaro was Moll’s first restoration project, he paid a visit to Young’s Auto, in Muskego, Wis., to get advice, and then borrowed some of the shop’s equipment. Bruce Young of Young’s Auto suggested Moll use a gravity-feed blaster to clean the Camaro’s metal areas that could not be reached with an orbital sander. Many hobbyists completing serious rust and paint removal will discover that nothing beats blasting for cleaning metal.
Moll used sand as his blasting media, but did not blast the whole car, because sandblasting large and/or straight body panels can potentially warp them. As a result, Moll stuck to the orbital sander to strip body panels, such as the fenders and doors. He did blast the rusty areas around the car’s side windows, as well as the floor pan. Then, with wheels and tires on the Camaro, he lifted the rear of the car fairly high in the air with an engine hoist and then supported the body with other safe methods. This allowed Moll to blast under the Camaro.
The large upright air compressor in Moll’s garage sucked the sand from a canister located near the car. A large tarp spread beneath collected the sand, which could be cleaned up with a shop vacuum.
To avoid inhaling silica particles from the blasting sand, Moll wore a full hood whenever he blasted, plus other safety equipment, such as sandblasting gloves and full-length clothes. The media agent can get in every crevice inside and outside of a car and a person, so safety shold be of the utmost concern. (See sidebar for important safety information.)
Moll used sawhorses to support nearby parts previously removed from the car and sandblasted them at the same time. Since sand is a relatively hard media, it removed the rust and old paint as Moll hoped.
Rather than use a blast cabinet, Moll blasted smaller parts by holding them over a wooden box using a special gun designed for smaller parts. He was careful to wear gauntlet-type leather gloves while blasting, as the pressurized sand can blast away skin. Blasting media bites into the metal, giving it a gray color and a slightly porous texture. Soon, the underside of the car looked like it had been coated with gray primer, which is exactly what should follow the sandblasting process. Moll sprayed a DuPont epoxy primer on the areas he had blasted to prevent flash rust from forming. Then, he could begin contemplating body work.
- Be safe when blasting — the process can remove skin and the material gets everywhere on the vehicle and the blaster. It can also release dangerous agents that should not be inhaled or ingested.
- Keep your ears covered when blasting.
- Wear an untucked long-sleeve shirt that extends lower than the waist on your full-length pants.
- Use a respirator with fresh filters rated for paint and silica. The respirator should completely seal over the area it covers.
- Wear a protective hood with a built-in face shield.
- Use heavy gloves made for sandblasting.
- Use (or rent or borrow) a cabinet that is big enough to work smaller parts. There is nothing worse than trying to blast a part if the cabinet is too small.
- Be prepared to collect the media after blasting with it. There may be specific environmental regulations for collecting and disposing used media materials in your area.
- Use the proper nozzle for the media that you are blasting.
- Make sure your compressor is up to the task. Running a sandblaster is hard on a compressor and will cause it to run the entire time. Take breaks to let the compressor cool when blasting for long periods.
- Many sources recommend a minimum compressor size of 60 gallons with at least a 7-hp motor for blasting.
- Sand is the media most likely to warp metal. When using any media, don’t concentrate the blasting in one area for a long area period; this is the fastest way to heat the metal and cause it to warp, or burn a hole right through it.
- Thin, fragile metals can be destroyed in the blasting process, so be sure the material can take the blasting.
- Some experts recommend #1 Super-Fine Silica Sand because it is reusable, is far less likely to warp metal and does not clog equipment like media of a larger consistency. Silica sand does have health risks listed at www.cdc.gov, so non-silica media is an alternative.
- There are numerous combinations of compressors, blasting media, nozzles and work areas. For advice on your specific set up, talk to your body shop or the sources from which you obtain the materials.
If you liked this, you might be interested in:
- Old Cars Guide to Auto Restoration CD Volume 2
- Eddie Paul’s Paint & Bodywork Handbook
- The Collector Car Restoration Home Video Library DVD Set
More Resources For Car Collectors:
- Classic car price guides, research, books, back issues of Old Cars Weekly & more
- Get expert restoration advice for your classic car
- Get car pricing, data and history all in one place
- Sign up for Old Cars Weekly’s FREE email newsletter
- Need to buy or sell your classic car? Looking for parts or memorabilia? Search our huge online classified marketplace