Spray Gun Compressed Air Filter Guide
Clean air for your spray guns is critical in achieving the finish you desire. Contamination in you filter air can result in fish eyes, dust in your finish, adhesion problems, poor gloss, and poor coating performance. These issues cost both time and money in your painting and are critical to reduce and eliminate. Fortunately, with proper air filtration you can prevent these issues from occurring.
Types of Compressed Air Filters for Spray Guns
There are a variety of compressed air options for spray guns but they will primarily be in two categories those that filter air near the spray gun and those that filter air at the compressor. Both options have benefits and drawbacks which we will discuss. Within each system you have 3 stages of air filtration. For an overview of the 3 stages of air flitration here is a good article covering the 3 stages of air filtration. The summary of air filtration is that it comes in 3 stages first is an oil water seperator, second is an oil water seperator with a coalescent filter, and the final (most clean air option) is an oil water seperator, coalescent filter, and dessicant dryer (which provides the greatest degree of clean air by taking the air down to a dew point removing all moisture).
Filtering air at the Compressor
Air can be filtered at the compressor using a refrigerant or desiccant dryer and an oil water separator. This has its pros and cons
- Will filter all air for your tools – this helps reduce any performance or equipment failure as the air will be clean for all your tools
- Only need to worry about maintenance for the equipment at the compressor vs needing to be aware of air filters that may be at various air line drops throughout your facility
- Save on equipment problems due to clean air throughout your plant
- Expense – a full refrigerant dryer along with an oil water separator for your compressor can be highly expensive. They can easily cost $16,000 or more.
- Desiccant dryers for compressors can cost more than even a refrigerant dryer
- If you have minimal air tools it will be a greater expense than is necessary
Filtering Air Near the Spray Gun (off an Air Line Drop)
- Will be less costly – A typical extractor and coalescer filter will cost around $600 dollars. Even a unit with dessicant (the cleanest degree of air you can have) is only around $800. This is significantly more affordable than a extractor and dryer for an entire compressed air system
- Will maximize the quality of clean air – By having the air filtered immediately prior to the source of the gun you remove any contaminants that might be residual in the plant piping from years of use or wear and tear
- Doesn’t filter air for all equipment which can result in damage to other air driven power tools