First, you need to know that this work requires a lot of air, which requires a compressor that can produce a high volume of air. Most newcomers focus on the HP of a compressor and the tank size, and both of those are of no concern to a glass blaster. The first thing you have to realize is that any compressor that will do a decent job for you requires a 220V outlet. For many individuals, that means getting a new 220V service installed. Space requirements may be a consideration as there are horizontal compressors as well as vertical ones.
The most important specifications to examine are the output of air at a given pressure. These specs are usually expressed as a certain number of CFMs (cubic feet per minute) the compressor produces at a given psi (pounds per square inch), which is a pressure setting. To do an adequate job at blasting most anything, you want to look for a compressor that delivers, at the very least, 11 to 13 CFMs at 90 psi. This should be your main focus. The size of the tank does not much matter, since any 60- or 80-gallon tank will be depleted in a matter of 10 to 15 minutes.
Compressors are also made in a few different quality categories, from home use to contractor use, to commercial use. With each category, the quality of the components becomes noticeably better and more heavy duty. Buy what you can afford to get started and keep in mind that you can always upgrade down the line.
-Ruth Dobbins, Professional Glass Consultants