Low CFM vs High CFM Spray Guns – A Complete Guide
Spray guns vary in the volume of air they need to be able to spray your coating. Air volume can often times be a problem depending on what other tools or applications you run in your shop. Typically your air compressor is one of the highest expenses in your shop and if you are limited on the Cubic Feet of Air Your Compressor Provides, you may be considering a spray gun that uses a small volume (CFM) of air. This article will cover the benefits and drawbacks of Low and High CFM spray gun air caps.
Low CFM Spray Guns
Low CFM Spray Guns use less air at the cap. The greatest benefit to a Low CFM Air Cap Spray Gun is that it will reduce the work on your compressor. However, the reduction in air consumption comes with a few drawbacks as well. The volume of air the gun will use differs depending on the model. In general, he lower the CFM of the air cap the less effective it will be at atomizing coatings, which depending on your specific coating will result in a lower quality finish. In addition, certain coatings will not be able to be sprayed at all without significant finish quality problems like orange peel. The reason for this is because as the pressure of air you spray at increases; the CFM of air you use increases as well. With heavy bodied coatings, you typically need a higher pressure to adequately atomize the coating which will also require a high CFM.
Who LOW CFM Spray Guns are Well Suited For
- Hobbyist with occasional painting projects and small air compressors
- Small solo wood workers who have limited compressed air availability and will be using lighter coatings
High CFM Spray Guns
High CFM Spray Guns provide the greatest versatility when it comes to their ability to spray coatings. Certain style guns like the Binks Trophy Spray Gun will allow you to change between air cap technologies. By having an adequate compressor for your spray gun and being able to use a conventional, hvlp, or LVMP air cap (which you can learn more about each here) you can have the ability to spray any coating you would need to. High CFM spray guns will also be able to provide a better finish. The better finish is a result of providing more atomization air to the spray gun which allows for better break up of your coating. The biggest drawback to High CFM Air Spray Guns is they require more compressed air. If you are limited on air volume in your shop you may not be able to support a High CFM Spray Gun. If you do not have the adequate volume of air for your spray gun you will notice that the pattern will be inconsistent and/or it will sputter because the atomization air runs out in the middle of painting.
Who High CFM Spray Guns are Well Suited For
- Industrial, Automotive, and Wood Working Professionals
- Hobbyist who have an appropriate sized Compressor
Ultimately by knowing what your goals are for painting you can better select equipment that is well suited for your application. By evaluating the finish you want, the coatings you plan to apply, and the air you have available you will be able to choose whether a High or Low CFM spray gun is right for you.