What Size Air Compressor For Sandblasting? [GUIDE] CFM For Sandblasting

If you have a sandblaster or you’re looking to purchase one for a painting project at home or in the workshop, you may now be wondering what size air compressor you need to run your sandblaster.

This page will serve as a guide into what size air compressor you need for your sandblasting by presenting all the key considerations and relevant information!

Table of Contents

• Key Considerations – Choosing an Air Compressor for Sandblasting
  • Are You Using the Sandblaster Intermittently or Continuously?
  • What CFM Rating Sandblasting Gun Have You Bought or Are You Considering Buying?
    • Example of a Small Sandblasting Gun
    • Example of a Medium Sandblasting Gun
    • Example of a Large Sandblasting Gun
  • What Pressure Rating Sandblasting Gun Have You Bought or Are You Considering Buying?
  • Air Compressor Duty Cycle
  • CFM Delivery Capability of the Air Compressor
    • Example of an Air Compressor Suitable for a Small Sandblasting Gun
    • Example of an Air Compressor Suitable for a Medium Sandblasting Gun
    • Example of a Large Air Compressor Suitable for Large Sandblasting Guns
    • Example of an Extra Large Air Compressor Suitable for Powering Multiple Sandblasting Guns Simultaneously
  • Air Compressor Tank Size (Compressed Air Storage Capacity)
  • Distance You’ll be Using the Sandblasting Gun From the Compressor (Hose Length)
• FAQs (Frequently Asked Questions)
• Reader Questions and Responses
  • How do I size an air compressor for sand blasting?
  • Can my Craftsman air compressor run my sandblaster?
  • Answer
  • Sand blaster air consumption?
  • Answer
  • Air needed for 5 gallon blaster?

Key Considerations – Choosing an Air Compressor for Sandblasting

There are a few very key considerations you must look at when finding an air compressor suitable for a sandblasting gun. These are:

• Use cycle – Continuous vs Intermittent Use
• CFM requirements & CFM rating of the sandblaster
• Pressure requirements of the sandblasting gun
• Duty Cycle of the air compressor
• CFM delivery capability of the air compressor
• Air compressor tank size (compressed air storage capacity)
• Distance you’ll be using the sandblaster from the compressor (hose length)

Are You Using the Sandblaster Intermittently or Continuously?

The first thing you must consider is whether you require require continuous or intermittent use out of your compressor for your sandblasting guns work.

If you only require intermittent use of your sandblaster then a small compressor may suffice but if you require continuous use then the compressor has to have the discharge capacity that the sandblasting gun demands.

A typical use cycle on a sandblaster in a non-assembly line environment is likely to be far less than 50% of the time drawing it’s full CFM rating.

What CFM Rating Sandblasting Gun Have You Bought or Are You Considering Buying?

Sandblasting guns come with CFM ratings, often expressed as SCFM ratings (as it’s a standardized unit). This can also be expressed as “Air Consumption”. For more information on SCFM vs CFM visit our guide for air tools & air compressor ratings.

Example of a Small Sandblasting Gun

Here’s an example of a small sandblaster (probably more small-medium), the LWJDM pneumatic sand blasting machine which is rated at an average consumption of 6 CFM.

• Operating Pressure: 90 PSI
• CFM: 6

Example of a Medium Sandblasting Gun

This sandblaster handheld gun by Neiko is a medium offering that has a 7 CFM average air consumption according to its technical specifications. From browsing Amazon it appeared that the majority of Sandblasters available had an average consumption of 7 CFM.

• Operating Pressure: 90 PSI
• CFM: 7

Example of a Large Sandblasting Gun

Here’s an example of a larger sandblaster by Le Lematec. It’s rated at an average air consumption of 12 CFM with optimal operation within 90-100 PSI as per the product description.

• Operating Pressure: 90-100 PSI
• CFM: 12

What Pressure Rating Sandblasting Gun Have You Bought or Are You Considering Buying?

All air tools, air sandblasters being no exception, have a recommended operating pressures.

As presented in the previous section, both the LWDJM and Neiko sandblasting guns have a recommended operating pressure of 90 PSI.

The larger Le Lematec sandblaster recommends operating pressures between 90 and 100 PSI for optimum performance.

Note: it is important to not exceed the maximum operating pressure or operate on a pressure too low, to ensure you get optimum sandblasting results.

Air Compressor Duty Cycle

The typical duty cycle of an air compressor is normally 50% as can be seen in this Craftsman 919 manual. It states that the maximum compressor pumping time per hour is 30 minutes.

If you want to know more about air compressor duty cycles, how they’re expressed and calculated, you should read my article on air compressor duty cycles.

Here’s another example of a product manual which describes the duty cycle of a compressor in these terms:

“INTERMITTENT DUTY FORMULA

Pump-up time should not ordinarily exceed thirty (30) minutes or be less than ten (10) minutes. Shutdown periods between cycles of operation should be at least equal to the pump-up time. Note: When the compressor is regulated by constant speed control, the shutdown period is the time the compressor is operating unloaded.“

This pretty much describes a 50% Duty Cycle.

CFM Delivery Capability of the Air Compressor

The CFM ratings of air compressors tend to be based on the output of the air compressor pump.

In order to understand what ability the air compressor has to deliver CFM continuously you need to multiply the CFM rating by the Duty Cycle percentage.

So an Air Compressor CFM rating of 14 CFM with a 50% Duty Cycle would have the ability to deliver:

14 CFM * 50% = 7 CFM

Example of an Air Compressor Suitable for a Small Sandblasting Gun

Here’s an example of an air compressor which delivers 2.4 CFM – and the product manual describes what would be determined as a 50% duty cycle. Therefore the compressor would actually deliver 1.2 CFM (2.4 CFM * 50%).

This compressor isn’t really suitable for any of the sandblasters. It could be suitable for a small sandblasting gun given that you only require intermittent use. But, this compressor wouldn’t be suitable for continuous use on any of the sandblasting guns presented in this article.

The small-medium LWDJM sandblaster requires 6 CFM, if the use was intermittent and only needed 20% of the time (12 minutes per hour), then the sandblaster only requires 1.2 CFM (6 * 20%). Therefore, this compressor would be capable of providing that that CFM.

But, this isn’t ideal at all. You will be having to stop frequently for the compressor to keep up with the tools demand.

However, if you required to use the sandblaster on a 50% duty cycle, the sandblasting gun would require 3 CFM (6 * 50%). The air compressor running at it’s recommended 50% duty cycle would not be able to provide the amount of CFM required by the sandblasting gun.

It would only be able to provide the 3 CFM requirement if you overworked the compressor by running it on a 90-100% duty cycle which is strongly not recommended!

Example of an Air Compressor Suitable for a Medium Sandblasting Gun

Here’s an example of an air compressor which is rated 5.30 CFM – and though product manual does not describes the duty cycle, a customer Q&A response has declared that the compressor has a 70/30 (70%) duty cycle. What would be determined as 20-25 minutes rest after each hours use.

Therefore, this air compressor is actually capable of delivering 3.71 CFM (5.3 * 70%). This is undersized for continuous use of any of the sandblasters presented in this page.

However, if the sandblasting gun only required being used intermittently (50% of the time) then this compressor is suitable for not only the LWDJM sandblaster (6 CFM * 50% = 3 CFM) but also the medium Neiko sandblasting gun (7 CFM * 50% = 3.5 CFM).

If you were to obtain a sandblaster with a CFM of below 3.71 CFM then this compressor would be capable of delivering continuous use to that tool.

Example of a Large Air Compressor Suitable for Large Sandblasting Guns

Here’s an example of a large Air compressor, the Ingersoll-Rand 8 Gallon twin compressor capable of delivering 11.5 CFM with 100% continuous duty cycle.

This compressor is suitable for providing continuous use to the small LWDJM and medium Nieko sandblasters provided as well as powering the larger Le Lematec sandblaster intermittently (12 CFM * 50 % = 6 CFM).

If this compressor were to have a 50% duty cycle instead of its 100% duty cycle however, and therefore would provide 5.75 CFM (11.5 * 50%) it consequently wouldn’t be able to power any of the sandblasters continuously.

But instead, it could work intermittently if the LWDJM tool required 3 CFM (6 * 50%) and the Neiko tool required 3.5 CFM (7 * 50%).

Example of an Extra Large Air Compressor Suitable for Powering Multiple Sandblasting Guns Simultaneously

Here’s an example of an industrial air compressor which delivers 38 CFM – and the product manual describes what would be determined as a 100% duty cycle.

This is a stationary compressor, that has a continuous run & automatic stop/start feature making it capable of powering small, medium and large sandblasters continuously and even all of them simultaneously!

Air Compressor Tank Size (Compressed Air Storage Capacity)

Tank size will determine how much air is available to be drawn down at any time. This is also a key enabler in keeping a compressor within it’s duty cycle.

Therefore an 14 CFM compressor with a 50% Duty Cycle can be used to run an air sandblaster that’s rated at 14 CFM – if used intermittently with a sufficiently large air tank.

To keep a compressor running for at least 10 minutes with a sandblasting gun consuming 14 Cubic Feet of air per minute for 50% of the time, the storage capacity would be:

14 CFM * 10 minutes * 50% = 70 Cubic Feet of air (at atmospheric pressure (15PSI))

As atmospheric pressure is 15 PSI and the output pressure is 90 PSI and pressure and volume are inversely proportional 15 PSI / 90 PSI = 6

Therefore, you need 1/6th the volume of air at 90 PSI

70 Cubic Feet * 1/6th = 11.67 Cubic Feet

11.67 Cubic Feet = 330 Litres

This example is to give you a basic idea on the capacity needed.

Distance You’ll be Using the Sandblasting Gun From the Compressor (Hose Length)

Long hoses will result in pressure drop, which is not desirable. I could not find any recommendations in any of the sandblasting gun manuals, but it can generally be recommended that the hose length should not exceed being just long enough to serve the working area.

Any hose length over 25 feet will result in pressure drop that will need to be compensated for to ensure that the sandblaster is receiving the right operating pressure.

For further information on air hoses visit our Air Compressor Hose & Tube Guide.

FAQs (Frequently Asked Questions)

Reader Questions and Responses

How do I size an air compressor for sand blasting?

by Randy Murphy
(Piqua Ohio, USA)

I purchased a Snap-On Pressurized sand blaster, Model Y441 pressurized tank @ 80 psi.

It has a 1 inch delivery hose coming out of the tank. I have hooked up the supply line, which is .5 inch copper feed line, with a .5 inch hose.

Snap-On rep. said this unit should blow paint off down to metal with no problem. It take me two minutes to get a 1 square ft. area and lots of media. Please help suggest a fix.

Sandblaster CFM Requirements – Answer

Response: Hello Randy. From your post I understand that you feel that the Snap-On Pressurized sand blaster may be being under-powered by the .5 inch copper supply line versus the 1.0 inch delivery hose?

Am I correct in understanding that the 1.0 inch hose is the media delivery to the blast nozzle, or is that the compressed air supply to the blaster?

Randy, I don’t do much blasting, so I don’t know if 2 minutes to get 144 sq/inches of metal back down to clean profile is fast or slow.

I do believe that somewhere in the specs for the sandblast unit it should tell you what the compressed air feed flow rate for that blast gun, at 80 PSI is. That’s the info that will tell you whether you have enough flow or not.

What’s that spec, please? If you can’t find it, ask the rep.

The PRESSURE DROP page on this site has a chart to give you some idea of the flow through various sized orifices if that helps.

Anyone else?

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Can my Craftsman air compressor run my sandblaster?

by jdub
(wv)

I have a craftsman 1hp, 3gal air compressor.

Can i use this with a sandblaster, and if so what size will fit this small compressor?

Answer

Response: Jdub, it is pretty hard to answer this question for you without knowing a bit more information.

Your air compressor is pretty small, and will put out about 4 CFM of compressed air at 90 PSI at the very most, and that’s being optimistic.

Your 3 gallon air tank will supply a sand blaster for only a few seconds before becoming empty, and since your compressor is so small, it will be running continuously trying to catch-up with the air in the tank, and will not be able to do so while you are running the blaster.

You haven’t provided the info I, or you, need to determine if your air compressor is adequate so you do need to read the pages on this site regarding sizing an air compressor.

However, I strongly suspect that if you try to run your sandblaster with a 1 HP air compressor, you will not have any success. Sandblasters are high demand air tools, and your little compressor won’t even come close to the flow needed.

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Sand blaster air consumption?

by Matthew
(Albuquerque, NM, USA)

On your page about air consumption, it is listed that a sand blaster will consume 300+ CFM. That seems like a whole lot.

Maybe you made a mistake there on that page because I’ve looked at other websites and they list sand blasting CFMs a lot lower, I think that the highest listed that I saw was 150 CFM.

I’m just a hobbiest more or less, so I don’t need a huge compressor. What would you suggest? –Matthew

Answer

Response: Hi Matthew…

Your comment is a valid one in that there are hand-sized sand blasters that use minimal air, and sand blast booths that will use hundreds of CFM of compressed air to work properly. Graco sells a blast solution that uses 425 CFM, for example.

Rather than showing a range, I simply picked a high consumption number to force viewers to focus on knowing the CFM requirements of the blaster they wished to use.

You say “I’m just a hobbyist more or less, so I don’t need a huge compressor.”

Well, depending on the hobby, you may need a huge compressor, or, for example, if you are brushing a few small plastic models, a really small air compressor will do.

Which leads me to your question… somewhere in the specs for your air using equipment, should be information about that equipment’s air demand, typically in PSI and CFM.

I cannot suggest a compressor size, as I do not know what your air tool requirements are.

Without that information being used in the sourcing of your compressor, you are destined to either get one that is too big, to small, but rarely an air compressor that is right on in terms of air supply versus air demand.

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Air needed for 5 gallon blaster?

by Glynn Hancott
(Ontario Canada)

CFM = cubic feet per minute – what is the volume of air that is required from my air compressor to effectively run a five gallon Sand Blaster?

Answer

Response: Glynn, we, myself and others who visit this website, can’t help answer this question except in generalities as the flow and pressure requirements for any air tool, including your sand blaster, are brand specific.

Then, you don’t say, but do you plan on blasting all day every day at work, or are you just doing a small job, a one off, for example?

The amount of blasting you will be attempting will have a bearing on the size of compressor and tank required.

I can’t be sure, yet based on trying to blast with my little blast kit, my guess would be that for any kind of regular use, I expect you’ll need at least a three, and probably a five HP sized compressor, with a 30-60 gallon tank.

That’s just a guess, as you really need to find out what the specs for your blaster call for.

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If you have any questions regarding what size air compressor you need for a sandblaster, please leave a comment below with a photo if applicable so that someone can help you!