What type of respirator should I use for spray finishing?
I recently bought an HVLP sprayer. So far, I've applied water-based finishes while wearing just a cheap respirator. I'd like to get a better respirator for spraying other types of finishes.
—Tim Hollefsrud, Pierre, S.D.
If you're wearing just a disposable paper filter mask now, Tim, a respirator would be a big improvement. Any respirator you buy needs to pass two crucial tests.
First, the respirator must fit tightly against your face to keep fumes from bypassing the filters. To test for a tight seal, fit the respirator to your face as the manufacturer recommends. Then remove the filter cartridges and place your hands tightly over the cartridge mounts. Try to inhale and see if air is slipping in around the edges of the mask. If so, adjust the mask until you achieve a tight fit or try a different mask. Something as simple as facial hair can interfere with a mask seal.
Second, check whether the respirator can be fitted with the correct cartridges for the finishes you'll be spraying. Look for the filter's National Institute for Occupational Safety and Health (NIOSH) rating. Avoid filters with an "N" rating, which won't trap airborne oil particles. Use an oil-resistant "R" filter or oilproof "P" filter. In addition to the letter, there will be a number rating of 95, 99, or 100, depending on whether the filter works at 95, 99, or 99.7 percent efficiency. Any of these will be adequate for most household spray finishing jobs.
For protection when spraying both water-based and solvent-based finishes, look for a filter with an organic vapor rating. Some filter cartridges may be rated for both particle and organic vapor protection.
To protect your eyes and lungs at the same time, consider a full-face mask. Examples include AOSafety's QuickFit (AOSafety, 800/225-9038 or aosafety.com), shown above, or the 3M 6000 with a full facepiece (800/328-1667 or 3m.com/occsafety). These cannot be worn over glasses, but some types can be fitted with built-in prescription lenses. Removable plastic films can be applied to the facepieces to keep your vision from being obscured by overspray buildup.