Sandblast Cabinet Buying Guide
What Kind of Sandblast Media will You Be Using
Sandblast media comes in a variety of forms from steel shot, to plastic bead, to aluminum oxide. All sandblast media have a variety of properties that include friability, hardness, shape, and size for a more detailed discussion of media please see here. The point is each media has advantages and drawbacks, specifically different media types have different cleaning strengths, surface profile alteration abilities, and different speeds at which they can clean. Media that is highly abrasive like aluminum oxide will require lining of the sandblast cabinet to protect it from premature wear. Additionally heavy bodied media will not be able to be propelled well by suction. For a general idea of media types and their use see below.
- Steel Grit – comes in a variety of grades and is ideal for removal of product from a surface, steel grit will alter the profile of a product and is often a good choice for creating an anchor profile or removing rust. Heavy bodied steel grit will not work well with a suction sandblast cabinet
- Steel Shot – Steel Shot will allow for alteration of a surface through a process called peening. It can be used to strengthen a surface by compacting the metal into a condensed mass. Heavy steel shot will not work well with a suction fed blast cabinet.
- Aluminum oxide – This is more abrasive than grit and will allow faster removal of contaminants but with less life cycles
- Plastic Beads – Plastics are used to clean a surface without causing any change to the surfaces profile.
How do you Want to Deliver the Sandblast Media?
With all the variety of media there are also a variety of options as to how the media is delivered inside the cabinet. Media can be supplied by air pressure from a pressure fed cabinet, fed by a suction based blast cabinet, or even mixed with water to create a slurry in a wet cabinet. Pressure fed cabinets will clean parts faster than a suction fed cabinet but will cost extra. Suction fed cabinets will be more cost effective than a pressure fed sandblast cabinet and are often ideal for lighter production needs (<2 hour a day) they will also require less air (by about 1/2 the amount of air needed for an equivalent sandblast nozzle with a pressure cabinet) but will also be about 1/3 the speed of a pressure cabinet. Cabinets with water mixed are a great solution for a finish similar to plastic beads (where you want to polish a surface but not alter it) and they can also remove grease while polishing reducing cleaning steps. They can be more expensive and require additional maintenance due to water being included in the system.
Product Movement, Surface Profile, and Shape Considerations
If you have a large product you will need to think about how you will load, unload, and manipulate the part in the blast cabinet. It is recommended to leave a few feet on each part of your product to allow for maneuvering of the product inside the blast cabinet. Loading options can include a table that will slide and optionally rotate the product inside the cabinet allowing for ease of finishing, or certain cabinets offer a clam shell feature that open allowing a product to be inserted, or you can have a side access that swings open. The sliding table is easiest with heavy product, the side with a swing is the most affordable, and the clam shell is convenient for larger objects. The downside to a clam shell product is that they can have issues with containing media over the long term. If your product consists of uniform surfaces to be cleaned and there will not be a need for cleaning recesses or difficult to reach areas a mechanical driven sandblaster might be perfect for your needs. If you need a polished surface without any alterations you would want to consider a plastic bead blast cabinet or similar non abrasive media cabinet. If you want no surface alteration and removal of grease or similar contaminants you may want to consider a wet blast cabinet.
With so many variables to consider about buying a blast cabinet its important to evaluate all the variables to make sure it will support you in your production needs well. A reputable sandblast cabinet manufacturer will offer laboratory services that they will take your product and ask you for your surface profile goal. They will then run the product through a variety of pressure’s and media types to achieve your desired surface profile. A recommendation of media type and pressure settings will be given. This will determine the style cabinet best suited to meet your production needs and product profile goal.