Sandblasting can simplify even the most difficult and most complex sanding jobs. An air compressor is needed to do any sandblasting, so knowing the right size air compressor to use is very important.
Generally speaking, most sandblasting jobs can be accomplished if your air compressor has a 5 to 10 gallon tank, can produce 90-100 psi. For smaller jobs the air compressor must have 10 CFM of airflow, but for larger, more heavy-duty sandblasting operations, 30 CFM would be required. However, When it comes to what size air compressor for sandblasting, it will depend on your application.
The problem is that finding out what size air compressor to use for sandblasting can be difficult if you are unfamiliar with air compressors in general.
In this article, we will go over everything you need to know about a sandblaster’s compressed air requirements. We will also discuss how a sandblaster works.
What Is A Sandblaster Used For?
Sandblasters use compressed air to blow sand onto surfaces at a high speed. This works very well to strip off rust, dirt, grease, or even paint. People use sandblasters for all kinds of tasks ranging from preparing a surface for repair and refinishing to restoring something to its original condition.
The sectors that make the most use of sandblasting are the automotive and ship-building industries.
What Are The Size Properties Of An Air Compressor?
While there are many properties of air compressors, the three most important when it comes to sandblasting are its tank size, CFM rating, and PSI rating.
The second important factor is CFM, or Cubic Feet per Minute. CFM is a measure of how much air a compressor can move, in volume. The last factor is PSI, or Pounds per Square Inch. PSI is the measure of how much force the compressed air has behind it.
1.Tank Size
An air compressor’s tank size will determine how long it can run before the compressor has to kick back on.
If you are dealing with a 50% duty cycle compressor, then you are going to want at least a 10 gallon tank for sandblasting. If you have get a 100% duty cycle compressor, however, most medium-duty sandblasting jobs can be done with a 5 gallon tank.
2.CFM
CFM is air volume or total airflow that a given air compressor is capable of. When it comes to sandblasting, an air compressor that can do 10 to 20 CFM is ideal for simple sandblasting tasks.
If you are doing a little more work and need some more power, then you should use a compressor that can do 25 to 35 CFM. Taking it a few steps further, you would need a 50 to 100 CFM air compressor to do industrial-scale sandblasting work.
3.PSI
This is the amount of force or air pressure that can be generated by a given air compressor. To find the correct PSI for your job, you will need to know how much PSI your equipment requires.
How Much PSI Does An Air Compressor Need For Sandblasting?
Tank volume is represented in gallons and is a measure of how much air your air compressor can store. For sandblasting, it’s important to have a decent-sized tank.
As a general rule of thumb, when it comes to sandblasting, the higher PSI the better. That means you will have to spend a lot less time cleaning up afterwards (unless you have an enclosed box for sandblasting) because you will easily be able to blast away the sand that went all over the place when you were working.
You want to make sure that you have an air compressor capable of at least 100 PSI for sandblasting.
What Size Air Compressor Nozzle Is Needed For Sandblasting?
There are many different ways of sandblasting and they each require their own speeds and pressures.
It’s important to keep in mind that the larger the nozzle, the higher the PSI and CFM will need to be to be able to support the larger size. This is because as you reduce the volume of the air’s vessel, you also decrease its pressure.
So, if you have a medium-sized nozzle and need more speed but your air compressor is already cranked to max, you can just get a smaller nozzle. Below are two examples of some common nozzle size, PSI, and CFM combinations.
- If you are using a No. 2 nozzle and your air compressor can do 100 PSI, then it needs to also be able to provide 20 CFM of air flow
- If you are using a No. 2 nozzle and your air compressor can do 140 PSI, then it needs to also be able to provide 28 CFM of air flow
The size of the nozzle is important when sandblasting because the size of the nozzle affects the blast pattern.
Going up one size typically increases the blast size by 10%. So, if you are trying to do precision work you will need a smaller blasting pattern. For this, a No. 4 or No. 5 nozzle, which measures 3/16 inch and 1/16 inch, respectively, is recommended.
If you are needing a larger area, then the good news is that you can work much more efficiently if you use a larger nozzle size. For this you can use anywhere between a No. 6 and a No. 9 nozzle, which range between 3/8 inch and 1/2 inch.
NOTE: Nozzles do not last forever. As they age, they lose their stiffness and begin to flare out a bit. So, an old nozzle will require a lot more CFM to maintain a set target pressure.
Other Considerations
In addition to the things we have already talked about such as PSI, CFM, and tank size, there are a few other key aspects that need to be taken into consideration when you are trying to find out what size air compressor to use for sandblasting:
- The air compressor’s duty cycle
- Sandblaster-to-compressor distance
Duty Cycle
The best air compressor for sandblasting will have a 100% duty cycle. An air compressor’s duty cycle is a measure of how long it can stay on and running compared to how long it has to stay off to rest or ‘cool down.’
So, if you have a rather large job and cannot afford an air compressor with a very large tank, it’s best to make sure your air compressor is 100% duty cycle. This will ensure that it can stay running as long as you need it to.
If you are limited in budget or for whatever reason cannot find an air compressor that you like that has a 100% duty cycle, then you should go for something that has no less than a 50% duty cycle and a 10 gallon tank.
CFM
The amount of CFM you need comes down to your particular sandblasting gun. So, check the marketing material or product packaging for your gun and see how much CFM it requires. You will find this measure often labeled as SCFM which means standardized CFM. It may also be listed as ‘Air Consumption’ or ‘Air Requirement.’
Examples of Various Sandblasting Guns
Light Duty – Neiko 30068A
This Neiko hand held sandblaster gun is light-to-medium duty device and it requires 7 CFM of air flow according to its manual.
This sandblasting gun is great for small tasks like etching glass or mirrors. This can also be used to remove paint, oil, rust, and other forms of oxidation, dirt, and muck from all sorts of surfaces.
PSI Required: 90
CFM Required: 7
Heavy Duty – LE LEMATEC Portable Sand Blaster
On the other end of the spectrum we have the LE LEMATEC Portable Sand Blaster. This sandblaster is a larger machine meant for much more heavy duty work than the sandblaster mentioned above.
This one needs at least 12 CFM of airflow to run and at least 90 PSI to properly function.
PSI Required: 90-100
CFM Required: 12
When it comes to finding the right size air compressor for sandblasting, its important to remember this: Just like any other air tools, sandblasters have recommended operating pressures that are listed in their marketing material.
As you can see from the above examples, whether it’s light or heavy duty, most sandblaster guns require about 90 PSI to operate.
Note: For the best sandblasting experience, make sure to not exceed the maximum operating pressure of your gun. It’s equally important to nor operate on too low of a pressure, either..
Frequently Asked Questions
How Many CFM Do I Need For Sandblasting?
For smaller sandblasting tasks you generally need an air compressor that can produce somewhere between 10 and 20 CFM of airflow. Larger jobs like sandblasting the paint off of an entire car require an air compressor that can do 20 or more CFM.
How Much Air Pressure Do You Need To Run A Sandblaster?
Most sandblasters need at least 90 PSI to operate. Some of the larger models recommend ’90 to 100′ PSI. There are, however, a class of very small sandblasters that are used for ultra-light-weight tasks. Ultra-light duty sandblasters can run on as little as 50 PSI.
How Many CFM Do I Need For a Blast Cabinet?
While the exact CFM will vary depending on the size of your setup, generally speaking, most blasting cabinets need an air compressor that can do somewhere between 10 and 20 CFM paired with a small nozzle. This is usually fine for light-duty, intermittent use.
Conclusion
Sandblasting is a useful skill and it can make even the most difficult and most complex sanding job seem really easy. So, if you are new to the trade, it can be really useful to know what size air compressor is best for sandblasting.
Most medium-duty sandblasting jobs can be carried out with an air compressor that can produce 90 to 100 PSI at 10 to 30 CFM of airflow while storing it in a 5 to 10 gallon tank.
We hope this article helped you find the best size air compressor for sandblasting. Thank you for reading!