Soda Blasting and Paint Stripping

Hi Everybody! Welcome to my blog about soda blasting, the environmentally friendly cleaning method that uses a form of baking soda (sodium bicarbonate) in place of other non-environmentally friendly, and health hazardous blasting medias like sand.

In my earlier postings, I explained what soda blasting is, what makes soda blasting such a unique cleaning process, some basic information on air compressors, and on soda blasting equipment. Once you understand how soda blasting works, it is much easier to appreciate why it is such an effective, and safe, cleaning method for many different types of jobs.

Today, I want to discuss some of the basics about paint stripping and what you need to know to do the job properly.

Soda blasting is very effective for removal of most types of paints and coatings. Some common types of paint stripping jobs include: auto, truck, boat, motorcycle, aircraft, and various equipment restoration. Larger jobs like building and home restorations are also good candidates for paint removal using soda blasting. Graffiti removal too.

The first thing you need to understand is the selection of the proper soda blast media for your job. All soda blasters use “soda blast media”, which has a specific size, shape and type of crystal structure. Soda blast media is made in various formulations by various manufacturers for use in different applications. For paint stripping, there are several good types of soda blast media on the market, such as Armex Flow XL and Armex Maintenance Formula XL.

The next factor to consider is the type of material under the paint. Are you removing paint from metal, brick, stone, or some other type of hard material? Or are you removing paint on a soft surface like wood or fiberglass?
To start out, just set the air pressure (psi) on your air compressor to around 120 psi and forget about it.

All good soda blasters such as the ACE Model 2-PS, which I use, have an adjustable pressure regulator, which is used to set the final blasting pressure. For hard surfaces, a final blasting pressure in the range of 80 to 100 psi will usually do the trick. Just remember that the higher the blasting pressure, the more soda blast media you will use per minute, so avoid the “more is better” way of thinking. There is a point of diminishing returns. Just find what pressure works well, for that particular job, and stay there.

For example, let’s say you are stripping a car and the paint is being removed nicely at 90 psi. If you increase your blasting pressure to 115 psi, you might increase your productivity by 5%, but you might also increase your soda consumption by 20%. Remember, soda blast media cannot be reused.

On softer surfaces like wood or fiberglass, you want to avoid harming the underlying material. It’s best to start out at a low blasting pressure (say 40 psi) and slowly increase the pressure in 10 psi increments, until you find the “sweet spot” where you are removing the paint and not harming the substrate material.

For a hypothetical example, let’s say you are stripping boat bottom paint off of a fiberglass boat. Starting at 40 psi, it hardly does anything at all. So you increase to 50 psi and the paint is coming off a little better. As you increase in 10 psi increments, you get better and better results, until you get to 80 psi. At 80 psi, you don’t notice any increase in how well the paint is being removed than you did at 70 psi. At that point, just drop back to 70 psi. You have found the “sweet spot”. Of course, if you start getting into the gelcoat at any point, you want to drop back to a lower blasting pressure.

Regardless of the type of underlying material, you normally want to soda blast at about a 45 degree angle to the surface. Avoid blasting straight into the surface. For most jobs, move the spray forward in a gentle arcing motion from side to side. For narrow surfaces, like a window frame, the motion can be more linear. The distance from the nozzle to the surface will vary by job, so don’t be afraid to experiment.

I hope this helps you. In coming posts, I’ll discuss various soda blasting applications in more detail, along with tips and ideas to help you with your cleaning project or business. Thanks for reading!

– The Sodablasting Guy