Sand blasting is a quick and convenient way to remove unwanted material from just about any surface. A sand blaster can be used to remove rust and other debris from metal. It can also be used to remove paint from a surface, either across the entire surface or in a targeted area, such as graffiti removal. Using a sand blaster is relatively easy, but there are a few tips that could help prevent new users from making costly mistakes.
A sand blaster works by firing sand toward an object at high velocity. When the sand hits the object, it will bounce back in your direction, so it is important to dress with safety in mind. Protective eyewear and a respiratory filter should be worn if nothing else. This provides the minimum level of protection.
If possible, visit a local paint store to purchase masking tape and a pair of disposable (paper) full body coveralls, including a hood. Draw the hood tight around your face and use the masking tape to seal off the wrists and ankles of the suit. A sturdy pair of gloves should finish off the ensemble. Sand has a way of finding a way into the smallest areas and is abrasive against the skin, so it is important to do everything possible to keep it out of your clothing.
Sand blasting requires two basic materials–sand and compressed air. Both are important. Having the right air compressor is where most people make their first mistake with sand blasting. Sand blasting requires a minimum pressure of 60 to 70 PSI, with 90 to 100 PSI being considered ideal. Most private air compressors can only run constant at this rate for a few minutes before you will have to stop and give the compressor time to rebuild. This stopping and waiting will eventually get the job done, but it will take a long time. Using a larger, commercial air compressor is required for any large sand blasting job.
Using the right sand is also important. The sand should be small, of uniform shape and size and free of any debris (pebbles, tree bark, etc.). Many people like to use bags of commercial sand designed for children’s sand boxes, which seems to be perfectly suited for sand blasting. Most importantly, both the sand and the blaster nozzle need to be completely dry. If either is even slightly damp, the sand blaster will clog.
Sand is not only expensive, but it can be heavy to carry if you have bags of it to transport. By collecting and reusing the same sand, you will need to carry fewer bags and will also save money. Cover the area you will be working in with a large tarp. After you run out of sand, replenish your supply from the tarp. Use a sieve (sifting screen) to separate any debris or rubble from the sand before reusing it. This will prevent paint chips or other items from clogging the sand blaster.