Baking soda blasting with not-too-hard media for removal of surface rust on plated parts
When focusing on pure grinding power, baking soda media is less hard than alumina and glass-based media. Comparing the Mohs hardness, a unit that indicates the hardness of media, the difference is obvious, as alumina is about 12 and glass beads are about 6.5 while baking soda is about 2.5. Therefore, when baking soda blasting is used for stripping paint or removing rust, there is a concern that it may not be sufficiently effective depending on the thickness of the paint film or the depth of the rust. Even if the air pressure of the compressor is raised to increase the jetting power, it is of no use because the hardness of the media itself is low, to begin with.
However, baking soda blasting can be used to great effect by changing the purpose of the operation.
A notable example is the cleaning and rust removal of plating, where the wet application can clean dirt and surface rust spots without damaging the plating itself (depending on the degree of rust). Another advantage of using baking soda for rust removal is that it has a mildly alkaline property, so after application, the alkaline film provides a rust-preventive effect.
Water-soluble baking soda media is ideal for cleaning internal engine parts
When blasting with insoluble media, a rough feeling may remain even after careful cleaning, but the great advantage of baking soda media is that it dissolves and flows away with just a wash of water, so there is no risk of damaging the engine interior.
One of the most notable situations where baking soda blasting can best demonstrate its characteristics is when cleaning parts for engine overhauls, customization, and tuning. The inside of an engine dirty with carbon and oil is generally washed with an alkaline cleaning solution, but carbon stains stuck in the combustion chamber and oil on the inside of the crankcase are difficult to clean off even with a brush.
In particular, carbon deposits on the combustion chamber and valves cannot be cleaned off with a brass wire brush, and there is concern that a hard steel brush may damage the combustion chamber surfaces and valve seats. Dri-blasting or wet blasting with alumina or glass beads can be used to remove the dirt, but the media remaining inside the engine must be thoroughly removed. No matter how many times air blow is repeated, media tends to spill out silently, and even if an ultrasonic cleaner is applied while the parts are turned around, there tends to be a sense of uneasiness that cannot be assured that the parts are absolutely safe.
A baking soda blast is not hard enough to remove hard paint film and rust, but it is hard enough to remove carbon and oil stains. Above all, it can be sprayed into the combustion chamber, cam holders, crankcase interior, and oil lines without the risk of damaging the engine interior because it dissolves in water or hot water and leaves no media residue, thus eliminating the need for masking.
The more experienced users of sandblasting and wet-blasting will be shocked at the sight of a whole cylinder head being subjected to baking soda blasting without masking, but it is no exaggeration to say that this is the greatest benefit of baking soda blasting. When sprayed with a mix of tap water and baking soda media, the particles of baking soda strike and remove carbon from the combustion chamber, which is then washed away with tap water to remove surface dirt without scratching the aluminum material of the cylinder head or the valve faces, valve stems, and valve guide inner surfaces of intake and exhaust valves The spray is heavy on the surface of the parts immediately after spraying.
Immediately after spraying, the baking soda will leave a rough residue on the surfaces of the parts, but the baking soda will dissolve as the water continues to be applied. The baking soda will dissolve even more quickly if the parts are cleaned with hot water instead of water.
In contrast to sandblasting and wet blasting, which require a cabinet, baking soda blasting, which dissolves in water, can be used in the open air and has no restrictions on the size of the workpiece.
The baking soda blasting process is not always easy for everyone to use, as it requires a large horsepower compressor and other costs to set up the environment for comfortable use. However, it is good to know that by using baking soda as an abrasive, you can clean and remove rust from delicate materials without hesitation.
POINT
Point 1 - Baking soda blasting, which uses baking soda as an abrasive, has lower grinding power due to its lower hardness than abrasives for sandblasting or wet blasting, but has the advantage of cleaning without damaging the material.
Point 2 - Baking soda is water soluble, making it easy to remove media after blasting and safe to use for cleaning engine internals