HVLP Spray Gun Vs Conventional Spray Gun VS LVMP
Different spray guns have different benefits that stem from their air caps. Air caps are critical to atomizing your coating well and each type of air cap atomizes in a different way. Each cap also results in more or less transfer efficiency. As I have mentioned improving transfer efficiency is one of two keys to reducing finishing costs. In this article we will cover the differences between each of these air caps, there benefits, and there drawbacks.
HVLP Spray Guns
HVLP stands for High Volume Low Pressures. They use a lot of volume of air and convert it to a low pressure. The benefit is a soft spray that reduces overspray, which reduces coating waste and saves on paint costs. The drawback is that thick coatings are often not able to be atomized well. Heavy body coatings that will not atomize with HVLP well include Epoxy and Zinc Coatings. They are about twice as efficient as Conventional Spray Guns applying about 65% of your material to the target. However, a high quality HVLP Spray gun will usually cost more than a conventional gun (anywhere from 150 – 250 dollars more).
Conventional Spray Guns
Conventional Spray guns utilize air at a higher pressure than HVLP spray guns. The benefit is that regardless of how thick the coating is it can be atomized by increasing the pressure and atomization can be higher than HVLP. The drawback is that transfer efficiency is significantly reduced to around 35 percent which results in extra coating waste and increased coating costs. If you have heavy bodied coatings like glues, epoxies, and zincs conventional air caps often make the most sense. It is also the perfect option for a tight budget as they are cheaper than HVLP and LVMP guns.
LVMP Air Caps
LVMP stands for Low Volume Medium Pressure. LVMP spray guns take a smaller volume of air and produces a medium pressure. In essence, it uses less air than an HVLP air cap but with a slight bit more pressure than HVLP. The end result is that transfer efficiency is similar to HVLP air guns (around 60%). An LVMP gun will not atomize quite to the extent of a conventional gun (which atomizes more than any other air gun) but will provide a finer finish than HVLP as it uses more pressure to help break the coating apart well. This can be a great set up for wood stains and similar thin finishes that need the finest atomization. The drawback to a LVMP gun is that it is often not listed as meeting codes for emissions reduction. If you are under watch for emissions make sure to speak with your states environmental agency or do not use a LVMP air cap. They are also more expensive than Conventional Spray Guns.