It's gentler than sand.
To get a good idea of why baking soda blasting is so good, it might help to understand a bit about how the action of soda blasting is different from other types of blasting. To understand how it is different, let's compare sand blasting and soda blasting on a car fender. First, we look at the structure we are going to clean and simplify it to its most basic form. A car fender is metal coated with a layer of paint. The paint is very thin, only 7 thousandths of an inch thick. Easy enough.
If we were going to strip the car fender with sandblasting, we are projecting rocks that are three times larger than the thickness of the paint at the fender at a high velocity. The sand is denser than the paint, too. The force of the impact smashes and chops through the paint. The sand is harder than the metal as well. Any of the impact force that was not dissipated by the paint is now whacking the metal. Remember this is a thick, steady stream of sand. There is a lot of sand battering the bare metal and the surface ends up pitted and rough. The metal is stripped bare with only a dusting of the pulverized sand covering its scarred surface. Within hours, the ambient moisture in the air will begin to attack the metal and the process of oxidation (rust) will begin.
Now imagine what would be happening to this poor fender if it were made of glass or wood or brick!
For comparison, if we strip the car fender with soda blasting, we are projecting sodium bicarbonate at the fender, which is nearly the same stuff as in a box of baking soda from the grocery store, only it is manufactured differently so the crystals are a much larger, more consistent size. A crystal of our sodium bicarbonate is huge compared to the layer of paint. However, sodium bicarbonate is much softer and less dense than sand while still a bit harder than the paint so it can penetrate the paint layer just a bit and this is when the magic happens. Baking soda has a property called “high friability,” which means it goes to pieces. The bicarbonate crystal gets a little into the paint and breaks up. It doesn’t just crumble, it explodes! All of the energy that was projecting the soda at the paint is released outward and all of the bits and pieces of the crystal are carried along, ripping and shredding into the paint. The metal is harder than the soda, though, so it isn’t affected at all by that battle going on at its surface. What else is harder than Sodium Bicarbonate? Glass, plastic, chrome, rubber, gaskets. Let’s face is, sodium bicarbonate is that hardest-working wimp you will ever have the pleasure to work with!
When it’s all done and the fender is clean, there is an additional benefit to soda blasting. The bare, smooth metal has a light dusting of sodium bicarbonate. The dust is alkaline. For rust to form, there needs to be a slightly acidic pH. The alkalinity neutralizes any acidic component of the air and protects the metal! Pretty cool, huh? Soda Blasting has the same effect when cleaning off mold damage. Molds, and bacteria too, need an acidic environment to survive. When you soda blast, you are creating a safe, sterile surface.
The dust from the soda blasting can be rinsed off, it will dissolve in water. If there are any bits stuck in crevasses, they too will dissolve and rinse away. If I had sand blasted, I would have to rinse and wipe, and wipe and rinse. I would have to take extra care to make sure there was no grit left in any crevasses. Imagine all of that uncomfortable grit left over from sand blasting, little bits grinding into your floor, in the seams of your clothing, stuck between your teeth. When it comes to final clean up, baking soda being water soluble is a blessing. You can only get so much with a broom, being able to easily rinse away any remaining dust is a huge time saver!
Cleaning anything with soda blasting is a vastly superior process. You can easily remove carbon, grease, oils, gasket material, surface corrosion, paint and coatings from a variety of alloys, plastics and composites without substrate damage or distortion, and leave hard anodized coatings intact.
When you are soda blasting you are saving time by cleaning, degreasing and depainting all in one step. What better paint preparation could there be?
Kelso Restoration will get your project done right the first time. With offices in Milton and Ottawa, we are happy to service not only the Greater Toronto area and eastern Ontario, but also the entire of Ontario and beyond. Give us a call today.