Soda Blasting Paint Stripping - Master Blaster
A Different Type of Stripping
From the December, 2012 issue of Chevy High Performance
By Jake Amatisto
There is something about working on a project car that’s been taken down to bare metal that really motivates you to start thrashing to get it completed. Maybe it’s the peace of mind of having a blank slate to work with that flips a mental switch that makes you stay up wrenching until 3 a.m. on a work night; maybe it’s simply knowing that your carefully chosen paint scheme will be tied directly to the project without someone else’s terrible color choice from 1978 lurking underneath. However, motivation isn’t the most common reason why folks take their cars’ paint all the way off. Sometimes it’s what is “lurking underneath” that makes you want to tear off your project’s old skin to really assess what you’re working with.
In the past, when you wanted to strip a car’s paint to bare metal, you essentially had to remove it of all the trim, glass, and drivetrain before you could blast it. Sand media would pit and eventually break glass, and the trim would be annihilated by fast-moving particles. Also, sand media processes can actually heat up the metal through friction, causing it to warp in some cases. But there are safer and more environmentally friendly ways to strip your paint these days, and a soda blasting process is one of them.
Here is a shot of our Nova’s fender with the Aircraft Stripper applied, before we decided to get it blasted. The white layer of paint basically fell off, but it was the other layers below that put up a fight.
We started to use various...
We started to use various tools and grinders, but eventually realized getting it blasted was the best way to go since we preferred not to go mad.
The two most common reasons to get an old car blasted are to reveal any shoddy bodywork that may have been performed over the years and to get the car’s surface nice and smooth for a fresh coat of new paint. Sometimes you may pick up a project that you think is a solid specimen, only to find out years later that the quarter-panel was made of Bondo. Or, on the brighter side of things, you may think a project is junk, and it turns out not so bad. Albert De Alba at Cal Blast in Upland, California, can help you determine what you have by blasting all your old paint away—without removing the glass or trim. Cal Blast uses a sodium carbonate material, which is worlds “softer” than sand media—a substance common in industrial applications. For classic cars and restorations though, a soda blast is a much more viable choice, as it doesn’t heat the metal, yet is nearly as effective at removing coatings, such as paint, primer, old stickers, and body filler. Soda also leaves a protective invisible layer that will prolong your car from rusting right away, so you can actually drive the car around in bare metal. We did. However, soda is not aggressive enough to remove rust, so shops like Cal Blast offer a secondary copper blast process that removes rust as well as the invisible layer. If you opt out on the copper blast, you need to actually wash the bare car with soapy water before you can primer it, as it can create issues when the paint dries.
You may be wondering, why strip the paint off of your car when you can just paint over it anyway? Depending on the level of pickiness, car builders and/or owners don’t want to cover old paint because it can come back to bite them later. Body filler cracks, hidden rot, or shoddy bodywork, in general, can show up in your paint years later and also, if there is a hefty buildup of old paint layers, it can “fade” away body lines that would otherwise be defined.
Although we didn’t have to,...
Although we didn’t have to, we removed some of our Nova’s trim before getting it blasted. We actually lucked out on the hood trim piece; it has the cast letters still intact, which our Nova friends say is apparently hard to come by.
Here’s how the car looked...
Here’s how the car looked before the paint was annihilated by fast-moving soda particles. For average-sized cars like our Nova, Cal Blast charges a flat rate, however for larger vehicles that take more time, the cost can increase.
We opted to remove the Nova’s...
We opted to remove the Nova’s bumpers before driving it into the blasting booth. Four bolts were all it took for the bumper to be removed.
The taillights were also taken...
The taillights were also taken out, not because they would get damaged; we wanted all that encrusted dirt and grime that was hiding under the bumper and lenses to get cleaned off.
We made sure to cover our...
We made sure to cover our Nova’s tiny, tiny carburetor with duct tape, as well as a plastic bag. Also be warned that the soda material gets in every nook and cranny of your car, so if you are the opposite of us and care if the interior gets heavily dusted, you’ll want to tape up the windows too.
Albert De Alba Jr. is actually...
Albert De Alba Jr. is actually the man behind the mask at Cal Blast. The space suit lets Alba breathe without choking down gusts of paint and soda. Alba explained using the gun takes a little while to get used to at first, as the repetitive swooping motion of the gun builds muscles in your arm you don’t normally use.
Here’s an area that the soda blasting uncovered. Apparently there was some very light bodywork done to the car over the years, but nothing major. We were just glad there wasn’t another gaping hole here.
Here’s something else the...
Here’s something else the blasting revealed, some very strange-looking damage to the driver-side fender. The ideal way to repair this would be to replace the fender or have a fabricator build a patch panel; we’re not sure how we’ll address it yet, but it’s nice to know it’s there so we can see it repaired on our terms.
We were leery about the bodywork and paint on our newest project car, a ’63 Nova we’ve dubbed “The Hellion”, but we really didn’t want to take the car out of its running condition before we absolutely had to. Getting it sand blasted would require us to pull the glass and the trim and basically render the car undriveable for a while before we could afford to get it painted, so we made plans to drive the car to Cal Blast, get it stripped, and drive it with its metal and old dents all exposed until we had the scratch to paint it. We bought the car knowing there were about seven rot holes in the body, but it was relatively straight. Also, when we pulled the interior out, we were glad to see the floor was solid and lacking any rust holes. Still, we wanted to make sure there wasn’t any other hidden, worse rot under the paint. We originally were going to use good old-fashioned elbow grease to remove the paint ourselves using Aircraft Stripper and power tools, but it turned out our elbows didn’t have as much grease as we thought.
In one day we went from a curdled cream–colored Nova that had us wondering how much of it was made of Bondo, to a clean all-metal project ready and begging to be worked on. Follow the next few pages to see how it’s done—maybe Cal Blast can help you with your next project.
The material used is called...
The material used is called sodium carbonate, and it gets fed into a hopper as it gets used up. Sand, plastic, copper, walnut, and other media is also used for various blasting tasks, but Cal Blast uses soda and copper exclusively. The copper process is done after the soda blast. It removes rust (unlike the soda), the invisible layer the soda leaves, and it can also leave a very, very slight etch to the metal that helps primer stick more effectively.
Did we mention the soda gets...
Did we mention the soda gets everywhere? Well it does, just know that you’ll need to wash it thoroughly afterward, especially if you don’t want to breathe in the carbonate for weeks to come.
Here’s how the Nova looked...
Here’s how the Nova looked right out of the booth. As you can see, the car had various dent repairs over the years. Something to keep in mind when getting your old car blasted is the radiator. The blasting process must’ve removed an old patch job on our radiator because a pinhole leak in one of the fins had us scrambling for some J-B Weld. We fixed it and had it home before dark.
The soda carbonate media will leave an invisible film on the car that prevents it from developing surface rust. Yes, we did drive it for about a month with it all metal, and it still held this cool, wet metal look. If the body had less dents we’d probably just clear over the metal. Albert De Alba Sr. says you can actually have the car like this for a couple rainy days without any serious threat of surface rust; just remember to wash the exterior with soapy water before you plan on shooting primer, because it can potentially cause issues with the paint sticking.