How To Choose The Right Air Compressor Tank                        

The Right Air Compressor Tank Is Dependent On:

                  What the PSI of the tools required
                  What jobs are you going to use the compressor for 
                  What does the job require in running time to complete
                  How many tools will be operating off the same compressor
                  How much total CFM capacity are the tools

The tank and tool requirements must also be matched to the compressor rating, for instance you don't need a 60 gallon tank on a small Hp compressor. unless your using a lot of air tools at the same time, if you do then you need the Hp and pump capacity to keep enough reservoir for the tools to run without draining the air tank.

The tank is a buffer. It lets you use more air than the compressor can deliver for a short time. If you get too small a tank you won't be able to use more than the compressors output for as long. By having more reserve volume of air you can operate your tools by not running out of air pressure.
See 60 gallon air compressor for more information about air compressors and job requirements.

A air compressor tank should always be sized so that the compressor isn't running constantly. There should be enough tank capacity to establish an adequate amount of reserve air in the tank. The less time the compressor is running the less wear and tear. When compressors run they generate a fair amount of heat by compressing the air.

This can lead to more condensation, the hotter the air supply the more condensation will occur. Without an air dryer this could cause more moisture to condense on the interior of the tank which allows rust to form more quickly. The time of year is also a factor. Summer when the air is more humid will naturally produce more moisture and more condensation. If the compressor must run continuously in hot humid weather, the over heated air will hold a maximum amount of water vapor.

This is a major factor for paint spraying or any process where water in the line will be a problem, any time of year. The resultant condensation can get past the usual water traps and make it's way into the paint. Condensate will also build up in the tank more rapidly. See air compressor dryer for details on how to remove moisture.

You can not effectively connect several small tanks on one small compressor for more volume. Yes you get more volume but the small compressor pump runs forever to fill it. Always size the tank to the job requirements and the pump capacity of the motor.

 Rusting Of An Air Compressor Tank

Rust inside of an air tank is considered normal, so does that mean the tank will rust out fast? The tank won't rust out fast if you drain the water out after each use. The tank itself is not rust proofed on the inside as air tanks are welded and the heat would destroy any rust proofing on the inside of the tank.  There is no known way to effectively apply rustporoofing to the interior of the tank after assembly. It would be a very difficult job and it is impossible to say that the paint or other material would stick to the surface even if you could do it.