Blast Big: 10 Key Factors to Consider when Choosing the Best Blast Cabinet Air Compressor

So you bought a Harbor Freight or similar abrasive blast cabinet or maybe you plan on doing so. Either way you’ve arrived at the inevitable question, “What size air compressor do I need for sandblasting?” A variety of factors require consideration and the decision is more complex than you might think. The vast amount of choices can make things a bit overwhelming. Don’t despair. We’re here to help you choose the best blast cabinet air compressor!

If you’re new to shopping for air compressors, it can get confusing very quickly. Manufacturers and retailers throw all sorts of numbers and specifications at you: 60 gallon, 2 HP, single stage, 220v, 3.0 CFM at 90 PSI. Yikes. The good news is you’ll have a clear understanding of what all that means by the time you finish reading this article.

Things get even more complicated once you realize there are many different types of air compressors and sandblasters. No worries. We won’t be getting too technical with this post. However, we do need to briefly address some of the common features or specifications you’ll encounter on your journey. A good air compressor is an investment and can cost a significant amount of money. We hope this article can help you make an informed decision.

If you’re in a hurry, or don’t want to get into the finer details, here is the best piece of advice we can give you for choosing the best air compressor for an abrasive blast cabinet:

Bigger is better. Fortunately this simple rule of thumb will help narrow down your choices and make things much easier. We’ll get into all the details later, but we can boil it down to this general recommendation: buy a compressor with the best CFM output and the largest tank capacity you can manage with your available power source, space and budget. You want 10 CFM or better.

Seriously. Within reason, nobody has ever complained their air compressor is too powerful for blasting. You’ll hear all sorts of complaining from someone blasting with an undersized air compressor.

If you don’t have time for this whole article, we can provide you with 3 key pieces of information that will save you a lot time.

3 Important Points:

• The options available to you are limited primarily by two factors: your budget and what electrical service you have available as a power source.
• Compressor output is generally listed as Cubic Feet per Minute, (CFM). You need double digit CFM/SCFM output from an air compressor to make powering a blast cabinet with it practical. You can blast with less airflow but it is pretty miserable. Blasting with around 10 SCFM is doable but 12, 15, 18 or 20 CFM or greater is better yet.
• You won’t see double digit SCFM output from a single air compressor powered by the typical 110V/120V electrical outlet.. This is due to electrical limitations. You need 240V electrical to use a compressor capable of putting out 10 or more SCFM.

Curious what other specs you should be looking for? What do we recommend? If you’re looking for more information to help you chose the best air compressor for sandblasting, you are in the right place. We’re here to help. So what are the best features for an abrasive blast cabinet air compressor? There are a variety of factors to consider but we’ve carefully narrowed it down to the top 10 points we think you should evaluate when making your choice.

Top 10 factors for choosing the best sandblast cabinet air compressor:

1. Budget
2. Power Source
3. Air Tank Capacity (Gallons)
4. Maximum Pressure (PSI)
5. Horsepower (HP)
6. Airflow Volume (CFM)
7. Noise Level/Decibel Rating (DB)
8. Duty Cycle (Percentage)
9. Single stage vs Dual Stage
10. Air Compressor Type

1. Budget:

Your budget is going to play a major role in what solution you choose. It should be no surprise: the more you’re able and willing to spend on an air compressor, the better your blasting experience can be.

A good quality air compressor, when purchased new, is not going to be cheap. Pricing varies quite a bit depending on the brand and features. Generally speaking, if you are a hobbyist shopping at big box stores you should expect to pay in the range of $800 – $2500 for a middle of the road air compressor with specs in the neighborhood we recommend in this post.

If that budget is out of range don’t worry. You can get by cheaper. Buying used or refurbished units can be a great way to save money. If you’re on a very tight budget you can get by with an underpowered air compressor. If you must go that route just know blasting performance will be subpar, inefficient and a lot less enjoyable.

Of course, if your are buying a compressor for business or commercial use you can also spend much more than the range listed above. You could easily spend $3,000-$4,000 or much more if you were so inclined.

A decent compressor is an investment, especially if you use compressed air for more than a blast cabinet. A large and powerful blast cabinet air compressor will serve you well. You won ‘t regret purchasing something a little larger than you need.

2. Power Source

Other than budget, your main limiting factor when choosing an air compressor is going to be what electrical service is available at the desired location. If you’re new to the world of electric air compressors, this little piece of information will save you hours of research. The cold hard truth is, you need access to a 240 volt circuit for air compressors best suited for blasting.

More on this later, but you need at least 10 cubic feet per minute of airflow for any sort of consistent or productive blasting. In the United States, most residential electrical outlets are going to be 15 or 20 amp 110/120V outlets. We have a separate post explaining why, but these outlets can’t power larger motors needed for an air compressor producing 10+ CFM. You’ll be lucky to get 5-6 CFM out of most 120V 15AMP air compressors.

Powering a blast cabinet with a 110V/120V powered air compressor is an awful experience. It can be done, but it is terribly slow. The compressor will run pretty much non stop. You’ll get 30-40 seconds of blasting before waiting for the compressor to catch up again. It takes forever, or you overwork the compressor and shorten its life.

I know what you’re thinking. Don’t bother searching for a high cfm 120V air compressor. It doesn’t exist due to the electrical limitations we’ve discussed.

When shopping for an electric air compressor you may encounter the terms “single-phase” or “3-phase” in motor specifications. Most typical residential and commercial power here in the United States is single-phase. Three-phase power is typically found in an industrial setting like a factory. Higher horsepower electric motors often require or run better with 3-phase power. It is generally more efficient and can sustain a higher electrical load than single-phase.

There are ways around the electrical limitations if 240 volt electrical outlets aren’t accessible. Gas powered air compressors exist. Running a 220/240 volt air compressor off of a portable generator is an option. Some people make due by running setups with multiple 120V air compressors or by using a nearby electric dryer or oven outlet for power.

3. Air Tank Storage Capacity

Most air compressors will have a storage tank to hold a reserve of pressurized air. Air tank storage capacity simply tells you how much compressed air this storage tank can hold. This specification is typically listed in gallons in the United States.

Generally speaking, a larger air tank is better for sandblasting. In theory, a larger storage capacity means you’ll be able to blast longer before the compressor turns on and needs to refill.

So how big should an air compressor air tank be for a blast cabinet?

We recommend at least a 60 to 80 gallon tank.

Can you get by with a smaller tank? Yes. It can be done, but we don’t recommend it. What’s the absolute bare minimum we recommend? Central Pneumatic has a sticker on most of their blast cabinet or the packaging stating they don’t recommend anything under 30 gallons. We agree with their assessment. Anything smaller than a 30 gallon tank is probably found on a low output compressor that won’t be very useful for blasting.

4. Maximum Pressure

The maximum pressure a compressor is capable of producing is usually listed in Pounds Per Square Inch, or PSI. It gives a general idea of what sort of pressures you’ll be able to maintain at the blast gun or air tool.

Most of the electric air compressors you’d commonly find sold for home consumer use are going to have a maximum pressure in the 125-200 PSI range with 140-175 being very common. These pressures are all enough for siphon or suction sandblasting. However, bigger may be better here once again. We recommend a max PSI somewhere in the upper end of that range.

Let’s consider the low end. Will a max pressure of 125 PSI work for blasting? Assuming you are blasting at around 90 PSI or less then then answer is. Yes. However, the caveat here is the compressor’s CFM output needs to be sufficient for your blasting needs.

Selecting an air compressor with a higher maximum pressure can help counteract pressure drop and allows higher pressures that can make blasting a little faster. We’ve got a separate post on how blast pressure affects blasting speed, media life and airflow. While you may not need 150 or 175+ PSI at the blast cabinet you can always regulate the pressure down to what you do need.

5. Horsepower

Generally speaking, more power means better airflow and better blasting. The world of horsepower specifications for electric motors is muddy water. In fact, manufacturers used to love to use this specification to make their products look better than they actually were.

They would list “peak” horsepower ratings that the motor only produces for a fraction of a second at startup. These peak or “max developed” HP ratings can be over 5 times higher than actual running horsepower. They’re meaningless marketing gimmicks that end up misleading consumers. We care about real rated or running horsepower the motor can sustain in the real world.

There is a general rule of thumb when it comes to true air compressor electrical motor horsepower and airflow output:

Expect about 3-4 CFM per real horsepower at around 100 PSI.

• 1 HP = 3-4 CFM
• 2 HP = 6-8 CFM
• 3 HP = 9-12 CFM

Earlier we mentioned you can’t get double digit CFM airflow output values out of a 120V air compressor. The electrical limitations we spoke of directly relate to horsepower. Practically speaking, a 15 amp 120 volt outlet can’t safely power more than about a 1.5 HP single phase electric motor. In a perfect world, under ideal conditions with a 20 amp outlet you might be able to run about a 2 horsepower motor. The truth is with a single 110/120 volt unit you’ll only see airflow of about 3-6 CFM.

Want to know more? We’ve got an entire post dedicated to air compressor horsepower and how it relates to airflow and your blast cabinet.

6. Capacity or Airflow Output (CFM)

If you had to choose only one specification to use when shopping for a compressor, this would be the one. On your air compressor buying journey, all roads will lead back to cubic feet per minute of airflow.

The capacity of a compressor is basically the amount of air it can produce at a specific pressure. It is commonly listed in CFM which is Cubic Feet per Minute. It is essentially a unit of measurement that tells us the volume of airflow an air compressor can move in one minute. The higher the CFM rating, the more airflow you have. Don’t confuse this with tank capacity, which is usually listed in gallons in the United States.

There are a variety of different ways CFM is measured and listed by manufacturers. Air flow depends on a variety of factors and it can change depending on temperature, pressure, humidity and other variables. We’ve got a separate post explaining air compressor capacity ratings and the different types of CFM you might find listed. For now we’ll just say SCFM, if listed, can be a little better for comparing output of different units because it is measured under a set of standardized conditions. The problem is there are numerous different “standards” used. Knowing what standards the manufacturer uses is typically difficult. In the end you have to do the best you can and use whatever numbers are made available to you in spec sheets or product listings.

More Ambiguity – Don’t Use “Displaced CFM”

Many manufacturers and retailers will list a displaced or “displacement” CFM number when referring to airflow. Displaced CFM is essentially just a theoretical calculation of the amount of air a compressor should be able to displace or move. It’s one of those “in a perfect world” calculations. It doesn’t tell you much about the actual output in real world use. Therefore, it shouldn’t be used to judge how suitable a compressor is for any one particular task or tool.

Look for Free Air Delivery (FAD) or “Delivered” CFM Numbers

Delivered CFM is what we care about. Look for a specification showing “air delivery” when shopping for an air compressor. You’ll often see this labeled as “air delivery”, SCFM, Free Air Delivery (FAD) or something similar. You’re looking for SCFM or CFM listed at a certain pressure.

For example: 12 SCFM @ 90 PSI

In the U.S. manufacturers typically use SCFM when specifying compressor capacity, as demonstrated above. These specifications will give you a much better idea of what sort of real world airflow you can actually expect at working pressures. They’re almost always lower than the theoretical displacement capacity.

How many CFM is enough for a blast cabinet air compressor?

Some air tools require short bursts of air and a lower airflow rating may be acceptable. Tools that need a lot of continuous air flow need a higher capacity compressor. Sandblasting is very demanding when it comes to airflow. Generally speaking, the more CFM an air compressor can put out, the better suited it will be for abrasive blasting. This makes the CFM rating for a blast cabinet air compressor probably the most important specification to consider. Bigger is most definitely better here. You want the highest delivered CFM output your power source and budget will reasonably permit.

How much is enough for blasting? It depends on a variety of factors such as the type of blasting, media type and size, and the size of your blast orifice and nozzle. Keep in mind it is the blast gun orifice and nozzle size that dictate how much airflow you need. The size of the blast cabinet itself makes no difference.

If you’re looking for a reasonable ball park figure, shoot for at least a double digit CFM. Remember 10 SCFM at around 90 PSI is a good bare minimum starting point. You want as far above 10 as your budget and electrical service allow. You can blast with less than 10 but it is slow going with a compressor that can never hope to keep up. Would 15 or 20 SCFM or more be better? You bet!

7. Volume Rating or Noise Level:

The decibel rating (DB) of an air compressor gives us an idea of how loud the unit is. Bigger is not better here. A lower decibel rating number means a quieter air compressor. What exactly does quiet mean? It’s somewhat subjective, but here are some typical decibel ratings to give you a little better understanding of what decibel numbers mean:

So how loud are air compressors? According to Chicago Pneumatic, most modern air compressors fall into the 40 – 100 dB range. The lower end of that range are going to dubbed “silent” or “quiet” models. Realistically, the more affordable compressors are going to be louder. For the typical garage air compressor you should expect noise levels in the upper end of that range: 80 to 100 dB is common.

Generally speaking, oil-free compressors are going to be louder than oil lubricated compressors. Another general rule is, quiet compressors are going to be more expensive than louder ones.

8. Duty Cycle:

Many compressors are not designed to run continuously. Instead they are designed to run intermittently in cycles.

A cycle involves the motor running for a certain amount of time to provide pressurized air followed by a rest period to allow the motor and pump to cool off until the compressor needs to run again. One complete cycle is essentially the amount of time it takes to fill and use the storage tank.

A “Duty Cycle” specifically refers to how long a compressor can deliver pressurized air during a cycle. Essentially a compressor cycle has a work and rest phase. The duty cycle is the work part of the cycle when the compressor is running. This is often listed as a percentage. It is calculated by dividing the amount of time the compressor is on during the cycle by the total cycle time.

If a compressor has a 10 minute cycle time and a 50% duty cycle it would spend 5 minutes on and 5 minutes off. If the same compressor had a 30% duty cycle rating it would deliver pressurized air for 3 minutes and be off for 7 minutes.

Simply put, the duty cycle rating gives you a good idea of how long a compressor can run and how long you should be waiting for it to cooldown and rest. Keep in mind many affordable air compressors do not have any sort of thermal overload protection or other factors to ensure you’re not exceeding the duty cycle. It is up to you to not overwork your equipment.

Can you run a 50% duty cycle compressor at 80 or 90% duty cycle? Yes but it is ill-advised. This is overworking the unit and you run the risk of damaging or destroying it. At the very least you’ll be shortening the life of the motor and pump. Many manufacturers will say their unit is capable of running a 100% duty cycle but recommend running a 50% duty cycle for longevity.

What duty cycle is best for a blast cabinet air compressor?

Obviously a 100% or continuous duty cycle is best for abrasive blasting. You can make do with a 50% duty cycle, but bigger is better. Anything less than a 50% duty cycle is probably going to mean frustratingly slow blasting. Keep in mind you can always run a shorter duty cycle. You can run a 100% duty cycle at fifty or twenty five percent for example.

9. Single Stage or Dual Stage Compressor

Single stage air compressors compress air once. Air is sucked in and compressed by one or more pistons before being pumped into a storage tank. Dual stage air compressors provide higher air pressure because they compress air twice. The first stage compresses air to a lower pressure. The air is cooled and then compressed again to a higher pressure in a second stage before being pumped to the storage tank.

Compared to dual stage units, single stage compressors are more affordable. They’re probably a better value when it comes to a small workshop or do it yourselfer who occasionally needs smaller amounts of air in short bursts. Single stage units are often smaller, lighter and more portable than their 2 stage equivalents. Single stage compressors can be used as blast cabinet air compressors, provided the CFM output is adequate.

Generally speaking, two stage compressors are often better choice for blast cabinets. Two stage units usually outperform comparable single stage compressors.. Typically, dual stage compressors are more reliable, better built, and require less maintenance. They provide higher pressures, can provide more airflow and they often do so cooler, more efficiently and more quietly than their single stage counterparts. They’re often designed to provide large amounts of air with a long or continuous duty cycle. Of course, these benefits don’t come without a cost. Two stage equipment is usually more expensive, heavier and less portable when compared to similar single stage compressors.

A dual stage compressor may be more ideal for blasting but plenty of people blast with single stage units. If you blast occasionally for hobby or personal use, a good quality single stage air compressor with adequate airflow output will be fine. The minor benefits a two stage compressor offer a hobby user may not justify the added expense. If you blast regularly for business use, spending a little more to invest in a dual stage unit may be a better choice.

10. Types of Air Compressors

There are many different types of air compressors and we could go off the rails here diving into all of them. Fortunately we can narrow it down to the two most common types of air compressors: rotary screw and reciprocating compressors. There’s better news. For home and small shop use, reciprocating compressors are by far the most common.

Rotary compressors are probably better for meeting high demand blasting needs. We won’t get into the details here, but rotary screw compressors are often considered better built, better performing, quieter and longer longer lasting. They’re also many times more expensive making them beyond the budget of most normal DIYers. A new rotary screw compressor with adequate output will set you back at least several thousand dollars and it doesn’t take long to approach ten grand or more. They also are more likely to have special power requirements like 3 phase power. We’ll focus on reciprocating compressors. That’s what you are most likely to encounter and what you’ll probably be considering for a blast cabinet air compressor.

You guessed it. It isn’t as simple as deciding on a positive displacement reciprocating compressor. There are many different types of reciprocating compressors. Here are some features and subtypes you may encounter and our thoughts on each.

Gas vs. Electric

We’re assuming most readers desire an electrically powered air compressor. However, gasoline powered air compressors are available. They offer a good solution where adequate electrical service isn’t available or accessible.

Portable vs. Stationary

Portable electric air compressors often have wheels and a handle to aid with relocation. They’ll have a power cord that plugs into a standard electrical outlet. By nature of their design, they’re often smaller units with less output and less air storage capacity.

Stationary compressors are designed to be installed in a location and not moved. Large compressors with high output and large air tanks tend to be stationary. They often need to be hard wired into a location and often don’t come with a power cord.

Horizontal vs. Vertical

This refers to the air tank layout. Horizontal compressors are lighter and more portable. They’re easier to relocate since they have a lower center of gravity. Of course, there are stationary and portable versions of each.

Vertical compressors take up less floor space. Since the air tank is stood on end vertically, they can often be tucked into a corner out of the way.

Oiled vs. Oil-Free

Oil and oil-free refer to the type of lubrication used for the compressor pump assembly. Let’s take a look at both options.

Oiled

Oiled compressors are internally lubricated with oil, similar to the engine oil in a standard internal combustion automobile engine. Oil splashes on the internal pump parts and keeps them cool and lubricated. Most heavy duty compressors that run continuously in commercial or industrial use are oil flooded units.

Advantages of Oiled

• Potentially longer service life and better reliability.
• Probably provides better cooling and lubrication.
• May be quieter than an oil-free unit. Oil-less compressors have gotten less noisy over the years thanks to improved technology, however.

Disadvantages of Oiled

• Require maintenance like changing the oil and filters.
• Possibility of oil contamination in the compressed air
• Oiled units tend to be heavier and less portable
• Oil units may not be the right choice if being used in extreme cold. The oil can thicken and sludge in very cold temperatures.

Oil-Free

In an oil-free compressor, there is no oil. Instead, lubrication typically comes from a special chemical coating that provides lubrication over the life of the unit. For instance, many oil-free compressors use a Teflon coating to lubricate pistons or piston rings.

Oil-Free Advantages

• Often cheaper.
• Lighter and more mobile.
• No possibility of oil contamination in the compressed air stream.
• Not affected by use in extreme cold.
• Require less maintenance.

Oil-Free Disadvantages

• May not lost as long, especially with heavy use
• Typically run hotter.
• The special coatings used for lubrication can and do wear out.
• While these compressors require less maintenance, that doesn’t mean they never break.
• Generally regarded as louder than oiled units. However technology has improved and quieter oil-free compressors are available.

So which one is better for a blast cabinet air compressor: Oiled or oil-free? For blasting it doesn’t matter a great deal and much of this decision will come down to personal preference.

Conclusion

So there you have it: our list of the 10 most important factors to consider when purchasing a blast cabinet air compressor. Here our are basic recommendations. Of course, these are our opinion. You can get by with less but it is not an experience we would recommend. We’ll leave you with a summary of our recommendations:

• Airflow Output: 10+ CFM at 90 PSI. Ten should be considered the bare minimum. More is better. 15-20+ is better yet!
• Tank Capacity: At least a 60-80 gallon air tank
• Duty Cycle: We recommend a 100% duty cycle. You can make do with 50%.
• Max Pressure: 150 PSI or above
• Oiled or oil-less: Personal preference. We prefer oil lubricated.
• Single Stage or Dual: Dual is generally better for blasting but a quality single stage with adequate CFM output is perfectly fine for occasional normal home use.

Not sure what to start? No worries! We’ve gotten started for you and rounded up some potential air compressors at major national retailers and more. Check them out using the links below:

eBay is a fantastic source for air compressors both new and used.

Browse potential compressors at Amazon

10+ CFM air compressors at The Home Depot

At BlastBig.com our site and products like our metering valves are designed to help you get the most out of your air compressor and blast cabinet setup. They allow you to blast at a lower pressure and allow you to adjust the rate of media flow. Feel free to contact us with any questions and we’ll do our best to help. Good luck on your search!