What is the Best Type of Spray Gun For Wood Finishing
Applying a finish to wood is the final step in many wood shops work. It is also one of the first things a customer notices and can say a lot about the quality of the product you produce. To achieve a quality finish their are three important things to consider, your prep of the surface, the coating you apply, and how you apply it. The focus for this article is how you apply it and specifically the best type of spray gun for wood. Ultimately the best type of spray gun will depend on a variety of factors.
Type of Coating You Are Spraying
Wood finishes usually come in a few main categories including stain, sealers, topcoats, varnishes, and paints. Each of these will be applied slightly differently. If you are applying light bodied coatings only like stain, sealers, topcoats, and varnishes they can be sprayed effectively by gravity, pressure, air assist airless and suction fed spray guns well. A gravity fed or suction fed spray gun will make sense especially if you will not be using a lot of coating at a time if you will spray more than a quart or two you will want to consider a pressure fed spray gun with a pressure pot or if you need a lot of production an air assist airless outfit. If the coating you are spraying is highly viscous or “thick” such as latex paints you will be best using a pressure fed spray gun or air assist airless outfit with high production so that you do not have to thin your coatings excessively which can alter your coatings performance. Unlike gravity and suction fed spray guns which require material to be thin to flow through the gravity gun or be pulled up from the suction cup, air assist airless and pressure fed spray systems allow for fluid pressure to be increased to cause the coating to flow to the spray gun.
Spray gun technologies include HVLP, Air Assist Airless (which is similar to HVLP but high production) LVMP, and Conventional Spray guns. HVLP, LVMP, and Conventional come in gravity fed, suction fed, or pressure fed varieties. The cost of each technology and feed style varies. For example, a quality Binks or Devilbiss HVLP Spray Gun can often cost around $400.00 while a Binks or Devilbiss Conventional Spray Gun can be as low as $200.00. Meanwhile, an air assist airless outfit will cost between $3000 – $5000. In addition to the spray gun if you are going to buy a pressure fed spray gun you will need a pressure pot or 2 quart pressure cup which is good for smaller amounts of coating. Pressure pots and 2 quart cups do come in an outfit which provides all necessary hoses to spray as well as the pot and spray gun for about $500 – $900 dollars depending on the outfit you choose.
HVLP vs LVMP vs Conventional Spray Guns vs Air Assist Airless and Specific Recommendations
Each of these categories of spray gun have their benefits and drawbacks to wood finishing. HVLP, air assist airless, and LVMP are more efficient at applying coating to your product which reduces coating waste. Conventional however has the best ability to break up thick coatings and Air Assist Airless has the highest production ability with transfer efficiency similar to an HVLP Spray Gun. When it comes down to pure finish quality Conventional and LVMP guns will provide the nicest finish, but LVMP spray guns are more efficient making them a perfect choice for wood finishing with stains, sealers, and topcoats. For an idea of an HVLP Spray Gun vs LVMP Spray Gun check out this video review. If you are under inspection for emissions HVLP spray guns are a must because while a LVMP spray gun is similar in transfer efficiency to an HVLP spray gun, they are not typically approved for VOC reduction. If you want to be able to effectively spray a variety of coatings from the gun including glue, you would want to consider a conventional spray gun. Finally, if your looking for high production with a fine finish you should consider an air assist airless spray gun outfit. Some Spray Guns will even allow you to use them as an HVLP, LVMP, or Conventional Spray Gun by changing the air cap. The Binks Trophy Spray Gun provides this option and is a great fit for woodworking (it is the spray gun that is compared in the video mentioned).