How do I Size an Air Compressor for Sandblasting?

air-compressor-sandblasting

There’s a lot to know about sandblasting with it easily simplifying the most complex sanding jobs. Knowing what type of air compressor to use for sandblasting can be very confusing. Here’s your guide on everything you need to know about sizing an air compressor for sandblasting. But first, it’s important to know what a sandblaster does.

What do you use a Sandblaster for?

Sandblasting uses pressurized air to hurtle sand at surfaces, stripping off old paint, rust, dirt, and grease. Either restoring the item to its original condition or preparing the surface for refinishing and repair. The machines are most commonly used in the auto industry, in ship and rail yards and in other industrial applications.

After deciding to sandblast a surface you must choose the correct size air compressor for your job.

What is air compressor sizing?

There’s two important metrics you need to know for sizing compressors and sandblasters.

1. CFM (cubic feet per minute) 
This is the airflow or air volume that a compressor can supply within a minute. An air compressor which produces between 10CFM – 20 CFM is ideal for smaller sandblasting tasks. While a compressor which produces between 18CFM to 35 CFM is better for larger jobs where a more powerful experience is needed. While an industrial type of sandblasting needs a CFM of 50 – 100.

2. PSI (pounds per square inch): 

This is the air pressure generated by the compressor. The tank volume determines how long the compressor can produce air. To find the correct PSI for your job, you’ll need to to consider how long you will be running the tool and how many tools you’re using at one time on the compressor.

A higher PSI means faster cleaning, while these are more expensive you may feel the cost is worth the time saved. You should use a tank with a minimum of 100 PSI for optimum efficiency. If you reduce your blasting pressure by half, your pressure cleaning project will take four times as long.

You must consider both PSI and CFM numbers to make sure they work together.\

What Nozzle Size do I Need?

THE CFM, PSI and Nozzle size all work in unison, so once you have figured out your CFM and PSI, the nozzle size can be chosen. The larger the nozzle, the higher the air pressure and the more air your sandblasting will require.

  • No. 2 nozzle at 100 PSI, your air compressor needs to provide a CFM of 20
  • No. 2 nozzle at 140 PSI, your air compressor needs to provide a CFM of 28

The size of the nozzle affects the blast pattern, going up one size can increase the size of your blast by 10%. If you are working with a precise area of blasting a smaller blast pattern will be required. A nozzle size of 4 measuring 3/16 inch or nozzle size of 5 measuring 1/16 inch is recommended.

To work more efficiently you’ll need a larger nozzle size. Consider nozzle sizes between the range of 6-9 and measuring 3/8 inch to 1/2inch.

It is important to note that nozzles wear out, an old worn-out nozzle requires more volume per minute to maintain the target pressure. You must also increase the size of the compressor for projects with a higher PSI.

Important safety notes

Before operating an air compressor for sandblasting, ensure you have read the manufacturer's guide and you are complying with all the instructions. While sandblasting wear protective clothing including a dust mask, safety goggles, long sleeve shirt and long pants.

Where to hire a compressor?

Instead of looking for an air compressor for sale, you can hire an air compressor machine with iSeekplant. Here you can find the largest range of air compressors to suit any job size in Australia. Give iSeekplant a call today on 1300 691 912 or search for air compressors in your region here.

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