What is soda cleaning?
Soda cleaning is an environmentally-friendly type of media blasting that removes char/smoke, paint, dirt, coatings and other surface contaminants without causing damage to the surface being cleaned.
Unlike sand blasting, the action of the sodium bicarbonate used does not cause heat buildup, sparks, or abrasion to the substrata. Sodium bicarbonate is water soluble and in most cases, depending on your local laws, can be disposed of through conventional drainage systems.
The only material that needs to be disposed of is the contaminant removed, which can be separated by dissolving the blast media in water, and the use of a filter or centrifuge to separate the contaminant from the solution.
How does soda cleaning work?
The sodium bicarbonate used in the cleaning process is a larger particle than the baking soda used in the food industry, although it is the same purity.
The particles are propelled by compressed air through specialized blasting machines. Air pressures can be varied from as low as 20 psi on soft bases to 120 psi or more on hard surfaces. Water is used as either a dust suppressant or the propellant for some decontamination and paint removal. For surfaces that are somewhat softer, such as wood, water reduces the cutting action by as much as 20 to 30 percent.
What are the advantages of soda cleaning over sand blasting?
Unlike abrasive sand blasting, sodium bicarbonate particles remove contaminants by the energy released when the particles explode as they come in contact with the surface to be cleaned. Silica sand removes the material by wearing it away. However, when the sand hits the metal surface, the metal is also worn away and the surface is damaged.
Another major advantage of removing paint from cars or other metal surfaces with soda cleaning is the fact that sodium bicarbonate does not break the surface tension of metals, eliminating the problem of flash rusting.
Bicarbonate of soda is also a rust inhibitor which leaves a protective coating on the surface being cleaned. This allows for time to pass before the surface has to be repainted. This is unlike a sand blasted surface that must be repainted immediately. When the time does come to paint the surface, the protective coating can be removed by a light application of either vinegar or citric acid.
What about the heat build-up that happens with sand blasting?
There is no heat build up with soda bicarbonate, so warping is eliminated. Its nonflammable properties allow sodium bicarbonate to be used for cleaning in the petroleum industry where other methods could not be used. Sodium bicarbonate breaks down hydrocarbons, which makes it an excellent method of cleaning engines and engine parts, or other areas where oil and grease are present.
Static electricity is a by-product of using high pressure air. While soda cleaning reduces the amount produced, there is still a need to properly ground a metal object when using any blasting media. However, soda bicarbonate does not produce electrical sparks the same way that sand striking metal does.