All of the woodworkers I know like the woodworking part, but most of them dislike the finishing part. They have a great time using their tools to craft something beautiful and useful and then get paralyzed when it is time to wrap it up. They want it to come out perfect or at least really good, and are sure that they are going to mess it up. Usually, they have tried applying a finish with a brush roller, a cloth or all of the above and more, and the results were never great. It is possible to get a good finish with a brush or any of the above, but it isn’t easy and usually comes up short of perfection.
In the quest for a better finish, many woodworkers ask me about spray guns and spraying in general. They are looking for a better finish, a finish that is easier to apply and a finish that makes their hard work shine. Their reasons for not already owning a spray gun are numerous, but when I am asked if they should purchase a spray gun, my answer is always a loud and excited, “YES!”, followed by, “What in heck are you waiting for?”
On my list of essential woodworking tools, a spray system ranks near the top, only after a table saw, jointer and planer (and, logically I suppose, after sandpaper). I use a spray gun on nearly every project and for a multitude of reasons, with the main reasons being quality of finish, speed, speed and speed. Quality of finish is self explanatory, but the triple-speed thing may need a bit more description.
With a spray gun, the application is fast (speed #1). From spraying stain to applying the last coat of finish, the spray gun can move some material quickly. There is no faster way to get finish from the can to a project, short of just dumping it on. If the gun is working well and the finish is flowing nicely, I can often put down finish as fast as I can move.
The spray gun also allows me to use fast-drying finishes (speed #2) like lacquer or conversion varnishes, which are impossible to apply any other way. With lacquer products, the finish is often hard enough to sand and be re-coated in just 15 to 30 minutes, compared to a full day with oil-based polyurethane. Lacquer dries so fast, that I often spray parts just before heading to an install, throw them in the bed of my truck, and they are ready to install by the time I get to the job site. It can’t get much faster than that.
The best part for me, not being the most fastidious of woodworkers, is the time it takes to prep the spray area when using lacquers (speed #3). Besides covering areas from potential over spray, there is no prep required. I usually spray right next to my table saw or anywhere that I have room in the shop and do nothing about the dust. I just blow off the piece I am about to spray and get on with it. The finish dries so fast that dust doesn’t have time to get in it. I literally do nothing before I spray, even if I am standing in a pile of sawdust (the piece I am spraying is on sawhorses and not in the pile of dust, of course). I would never even think of working like this using something like an oil-based polyurethane, which seems to pull in dust from everywhere. (Quick note: I do use the gun to spray slow-drying finishes too, but the spray area needs to be clean and dust free, and I would prefer to skip that here in the speed, speed, speed section.)
Spray Gun FAQs
Besides the above four advantages, I am often asked additional questions when it comes to spraying, but I must warn you, the answer to all of them is still, “Buy a spray gun!” Here are some of the most common questions:
- Can I spray ________ with it? Yes, YES, yes, yes and YES! You can spray any liquid finish by changing its viscosity and/or your spray tips, if needed. It is no different from a brush – a spray gun is just a vehicle to move finish from the can to the project.
- I don’t have anywhere I can spray inside. Can I spray outside? I think outside is the best. Spraying outside requires no exhaust fans and usually provides ample space to work. Plus, it is just nice to be outdoors. I often move outside to finish large projects, or if I am out of room in the shop and need to spread things out. The best outdoor spot is a garage (with the door open), which has good ventilation, controlled wind, and a shield from the sun – a lot like an actual paint booth.
- What about the fumes when I spray indoors? Yes, there are fumes when spraying solvent finishes, but they can be dealt with quickly and easily. First, spray near a window with a fan in it (instant paint booth). Second, wear a mask while spraying. Third, don’t spray when your wife is home.
- Won’t the over spray get on everything? Sort of. The spray gun will shoot finish beyond the workpiece (over spray), but most of it will land in the form of dust. Fast drying finishes like lacquers dry almost instantly in the air, so only over spray close to the workpiece is wet and sticky. Even the over spray on the floor directly beneath the sawhorses just sweeps up.
- Isn’t a spray gun a pain to clean-up? No. If you stick to solvent-based finishes, like lacquer, that dissolve with lacquer thinner you only need to clean-up when the gun isn’t working right and then only by soaking the parts in lacquer thinner. If I am spraying lacquer, I treat the gun just like a can and leave the finish in it until the next time I spray. If you are using finishes that aren’t soluble after they dry you can’t be so cavalier, but it still isn’t a big deal. Often, it is only a matter of spraying the solvent through the gun until it is clean.
- After I berate someone for not already owning a spray gun and then tell them over and over again to buy one, the next question they ask is usually, “Which one should I buy?” My answer is simple, “Not a cheap one.” I have used several different high-quality, name-brand HVLP spray systems, and all of them did a good job. There are, of course, subtle differences in the way the guns work and some may be better than others, but none of the higher-priced systems will be a bad purchase. I have personally used HVLP systems from Fuji, Apollo and Graco, and all of them give similar results. At the same time, it is worth noting that I have used cheap no-name guns, and they were painful to use. The spray was splotchy and the guns would only put down a wet finish in the very center of the fan pattern compared to the entire width of the fan pattern from a good gun.
Spray Gun Choice Considerations
When selecting an HVLP gun there are lots of choices, and again, as long as you don’t buy a junk gun they are mostly just different, and not necessarily bad. I currently use an older HVLP system made by Graco. It has a turbine and a small compressor that pressurizes the 2-quart pressure pot for the gun. I use a pressure pot because it holds more finish, so I can refill less often and keep moving. Plus, with the pressure pot system the gun profile is small to fit into tight spots. For most uses and especially for those of you that don’t even own a gun, one without a pressure pot is fine, leaving you only to decide on two items, the type of gun (bottom-feed or gravity-feed) and the air delivery system (air compressor or turbine).
As far as the guns go, I prefer the bottom-feed gun because it holds more finish, and since it is the type of gun I started with, it just feels right. At the same time, I know several people who use gravity-feed guns with no complaints. They like that the gun is a little lighter and fits in smaller spaces, and they don’t mind refilling as often. Between the two there really is no bad choice.
The air delivery system is the other area to focus on when deciding which system to purchase. The guns can either be powered by an air compressor or a turbine, and you get to choose which makes the most sense for you. Again, neither is wrong or bad, just different. First off, do you own a large compressor (5 hp, 50-gallon tank)? If you do, and you don’t need to be portable, you can save some money and just buy a gun. If you don’t, I wouldn’t recommend buying a big compressor just to spray. I would spend the compressor money on a turbine unit because it is very portable. I know I often take my gun with me to the job site or just outside, and I appreciate not having to lug around a giant compressor just to spray.
Here are the key decision points to address when purchasing your new system:
- Do you already own a large compressor and don’t need to be portable? If you already own a large compressor you can save money by only purchasing a compressed air gun. Don’t buy a big compressor just to spray, spend the money on the more portable turbine system.
- Would you like to use your spray gun outside of the shop, maybe at the job site or at your house? Turbine systems are the lightest and most portable. If you need to take your spray gun with you, pick a turbine. If you are only spraying in the shop, either a turbine or compressed air system will work.
- Are your jobs big? Bigger jobs (full kitchens, for example) require more material and may benefit from a system that can hold more finish. If you are spraying very often or are consistently spraying large jobs, think about a system with a pressure pot. Otherwise, stick with a gravity-feed gun or bottom-feed gun. Note that even large jobs can be sprayed without a pressure pot, but will require more refills.
- Do you have extra money? Here’s your chance to spend it. None of the good spray guns are inexpensive. Expect to pay $800-$1,000 or more for a complete turbine system. And, remember, don’t buy a cheap one.
If you have been thinking about buying a spray gun, stop! There is no reason (except for money) to think about it anymore. Start living your woodworking dream and buy one. No one, and I mean no one, has ever been unhappy knowing that they had a good spray gun to use whenever they needed it. You will use it so much more often than you think, and, though a good spray system is expensive, it may make you actually enjoy finishing.
If you have any concerns about using or purchasing a spray gun, let me know below in the comments section. I am certain that I can allay any of your fears and maybe even answer a question or two.