In professional shops, where time is money, spray guns rule. And, new innovations in spray equipment have made this technique suitable for the hobbyist.
• Gun Type: High-volume low-pressure (HVLP) spray guns can be powered by a compressor (for large shops) or by a portable turbine blower.
• Check the specs: Atomization pressure at the spray gun, transfer efficiency, overspray, hose flexibility, and air temperature are important.
• Ventilate for safety: Always work with proper ventilation.
The most common spray-gun equipment uses a technology known as high-volume, low-pressure (HVLP). The original HVLP spray-gun system was powered by a high-output, high-pressure compressor, which is not ideal for the home shop. While professional shops can make do, home hobbyists or small shops are more likely to use newer turbine HVLP spray systems, which feature a gun and a small turbine-powered blower.
If you already own a compressor, you can buy a decent spray gun for as little as $100. You can also spend as much as $1,000 for a top-of-the-line turbine HVLP system, and there are plenty of choices in between.
Check the specs
Atomization pressure at the spray gun must be 2 psi or greater to spray most finishes successfully. Transfer efficiency, which is a measure of how well the gun delivers the finish, should be 65% or greater, running at air pressures of 10 psi or less, according to industry regulations. Aim for a low overspray rating, which refers to the amount of finish that doesn't make it onto a workpiece.
Ventilation for safety
When performed indoors, spraying should always be done in a well-ventilated area, either with a commercial spray booth or a shop-made one. The cost, both financially and in the amount of square footage a booth takes up, makes spraying less appealing to small, home-based shops. That said, it is possible to spray finishes outdoors, in good weather, but there are drawbacks, such as wind-driven dust and pollen, as well as insects that can contaminate the finish film.