Preparation is critical. Rinse the treated surface thoroughly with water to remove surface contaminants. If there is grease and oil residue on the surface, rinsing with water can reduce the sandblasting time by 50%. Salt contamination (chlorides, sulfates and nitrates) is also harmful. If the salt is not removed before painting, it will lead to loss of paint adhesion.
Stickers, tape, and decals can also require more time and abrasive waste if not removed early. Sandblasting these items can require 10 times more effort than removing paint.
The easiest way to test the strength of your paint is to run a knife across the paint. If you can easily scratch the bare metal, the paint will probably come off easily. If it takes two or more scratches to get to the bare metal, plan on spending more time and using more abrasive or a heavier abrasive to finish the job.
To protect the bolt threads, take a clear plastic tube the same diameter as the bolt and place it over the bolt.
To remove loose nuts and bolts using a sandblaster, find a 2×4 or 1×4 and drill holes that match the size of the bolts. Insert the bolt into the hole and secure the nut on the other side. This will protect the bolt threads and allow you to clean the bolt head and nut.
To prevent abrasive material from escaping from holes, cracks, and cavities, prepare various plugs and bolts that can be used to block holes in engines, transmissions, brakes, and bearings. Be sure to remove all grease and oil residue beforehand, as holes under grease buildup can be easily overlooked.
The required equipment requires the nozzle to be turned at least a quarter turn per week during continuous use or occasionally at regular hourly intervals to ensure even wear of the lining.
When purchasing a new nozzle, find or purchase a drill bit or dowel that is the same diameter as the nozzle bushing. Then use it to regularly check the nozzle for excessive wear, which may indicate the need for replacement. Wear causes a loss of air pressure and reduced cleaning efficiency. For every pound of air lost, 1% to 1.5% is lost in cleaner operation. Abrasive waste from nozzle wear can also quickly accumulate. In some cases, the cost of a new nozzle can be recouped within a week by eliminating abrasive waste.
Don’t throw away worn-out nozzles; they can be used for blasting steel and concrete, as well as other non-standard tasks.
Sandblasting Technology The position of the sandblasting hose relative to the body is very important for efficiency, comfort and safety. When using 100 psi of air pressure, there will be significant back pressure in the blast hose.
When blasting a floor, use your body weight to push the blast hose toward you to absorb the air pressure. This can be done by holding the hose in front of your body or over your shoulders. In some cases, you may need to have an additional person behind you to help move and control the hose.
For high pressure blasting (100 psi or higher), it is recommended to position the nozzle at a 90° angle to the work surface. This allows the abrasive to impact the surface and create a clean bonding pattern (contour). The surface profile resembles an enlarged mountain range with many peaks and valleys.
When sandblasting small parts, it is helpful to do so on a table just below waist level. Place the items you want to clean in the middle of the table and begin sandblasting the area facing you. Once that surface area is complete, move the part (usually a quarter turn) to expose a new surface area. Repeat this until all surfaces are clean. Most 3D parts require at least eight strokes to complete. This also helps reduce back fatigue.
Instead of trying to dump a 50 or 80 pound bag of abrasive into a sandblasting tank, pour the material into a 5 gallon bucket where it will be easier to handle.
Small Parts and Discs If you have a lot of small parts to handle, consider building a stand with a mesh bottom. Deardorff bought some used grocery store shelves at a local auction to support his sandblasting of small parts.
For small parts, another option is to keep a few pliers on hand. Attach the pliers to the component as handles. Deardorff also uses a short piece of pipe welded to a flat base to hold the pliers while blasting. Of course, the tool will have to be moved to clear the masked area.
When sanding smaller rims, lay one rim flat on your work surface. Then place the other rim vertically on top of the first, sanding one side at a time. Once you’ve completed a section, simply use your free hand to rotate the rim you’re working on until you’ve finished the entire rim.
For larger wheels, place a 2-by-6 or 2-by-12 board in front of the workbench. Place the rim on the table so that the wheel rests on the board, just as the wheel would rest on the track. Then remove the rim from the board and sand the bottom of the rim. To finish one side, rotate the rim 180° and sand the other side.
Mixing one size or type of abrasive with another size or type of mesh can often provide better blast cleaning performance in certain types of applications.
For example, when dealing with heavy rust or scale, you can use a coarse-grained consumable abrasive to destroy heavy objects. Adding finer-grained abrasives to the mixture will allow you to further clean metal profiles.
When you are finished, empty the sandblasting tank. The small amount of abrasive at the bottom of the sandblasting tank will absorb moisture, which can also freeze in cold weather.
Post time: Jan-20-2025