HVLP Sprayer Techniques for Your Woodshop

When you're putting finish on a woodworking project, it's really hard to beat the benefits that we can get from HVLP. HVLP is high volume, low pressure. They work differently than guns that attach to an air compressor. Number one thing, significantly less over spray from this system than you're going to have from a gun that connects to an air compressor. Another thing that I really like about what we're looking at here is, in addition to the HVLP, and we're gonna talk more about that, we have a turbine here, this is what's providing the air to our guns.

So it's a self contained system. What's great about this is that with a compressor, we can get moisture and oil in the line, if that has the opportunity to migrate into your gun, into your finish, onto your project, that can be really bad. So the promise with the turbine is that it's gonna provide clean air so that we don't have that problem. With our guns, got two different setups here. This is a bottom feed gun, our other is a gravity feed gun.

The HVLP that we're talkin' about is compatible, is gonna work with either of these. Next thing we're gonna do is have a look at the controls on the guns and what it takes to get them set up so that you're getting this great finish I keep talking about. Now in the world of accessories, one of the things I think merits a mention is this flexible hose that's on the end of my turbine hose. So, this darker blue hose is the one that came with the turbine and it works fine if you're working on larger areas where you don't have to do a lot of movement, a lot of intricate movement with the gun. What I found spraying furniture and cabinets, wanting to get the inside surfaces, this whip has quite a bit more flexibility to it and made it a lot easier to get to those interior surfaces.

Makes it a little bit easier to have a fluid motion of the gun. So, as I said, next thing we're gonna look at setting up the gun. Following that, we're gonna look at spraying a project, talk about more benefits and how to set up our HVLP system. Next step, let's look at what it takes to get the gun to operate the way we want it to operate. I'm gonna be spraying blue paint onto some white paper here so it's really easy for you to see the pattern.

Of course, all the setup that we do we can do with a clear top coat. The project we spray in just a little bit, we will be spraying a clear top coat onto that. So let's just talk through the controls a little bit before the turbine starts up and I put my mask on, so you can understand where we're going here. Got a hand full of things to work with. First, let's start here at the nose of the gun.

This is called the air cap. And one of the things we can do is get inside and change the nozzle that we're using based on the viscosity, the thickness, of the material that we're spraying. So that's internally, then the air cap right here, when these ears are in a horizontal position, the resulting fan is in a vertical position. Then of course if we do this, just the opposite. Now coming around to the side of the gun, the control right here is gonna let us very easily dial in the width of fan that we're spraying.

So, maximum width, and then if I dial that way down, which you're gonna see in just a little bit, that narrows it down. That would allow you to shoot say finish on just the edge of a shelf and nothing else. So we'll go back to wide fan. Back here at the end of the gun, this is our fluid control. So as I dial this way in, it reduces the amount of liquid we're gonna get through the nozzle, and as I dial it out, we'll get more liquid, you'll see that happen.

And then down here on the hose itself, there's kind of a gate valve. And that, just like you would intuitively imagine, controls the amount of air going to the gun. So one of the things this will do is if I'm getting a lot of bounce back from my project, over spray, then I can reduce that amount of air so that I'm not getting so much bounce back off my work. So let's go through, we'll do some test spraying here, and I'll tell you where I'm at right now. I've got that blue paint loaded, I've got my fluid control dialed way in.

So we're gonna get very little liquid to start. That's a good place to start to make sure that in your test pattern you're not just fire hose spraying your work. So we'll start real dry and then we'll increase that as we go to get more liquid coming out. I've got a helper gonna turn on the turbine for me when we're ready. And Jenny, I think you can go ahead and hit it.

We're gonna start at the top of the paper, see what we get. We're not getting enough liquid. We can open up the fluid control valve to allow more liquid to flow through. Remember that we can change the width of the fan. That setting will dial our fan width down.

We can change our air cap so the fan changes. And then again, if you're getting a lot of bounce back you can change the amount of air flow. All right, Jenny. So you can see, it's very easy on the fly to make the adjustments that you need to make in order to really control the quality of finish that you're applying. It's a great idea when you're spraying to start on test paper like this so that you can see the pattern that you're producing.

And again, in this case it's blue paint to make it easy for you to see. But if I was starting with a clear coat, I'd be doing the same thing. So, fluid control, width of fan, air cap direction, and again, you can change that nozzle size as needed in order to make changes that you need for the viscosity of your finish. And then finally, our valve here that lets us control the airflow itself to the gun. Now let's have a look at spraying a pretty cool project I made.

I've got my walnut handkerchief table laid out here, ready to spray. We know the gun is all set. So I'm gonna kick the turbine on. Wanna have the turbine removed from your finishing area, so you're not drawing air born finish back into the turbine. So I've got it off to the side.

As I work through this, you can watch for as I change fan direction depending on where I'm going, change fan size to spray different parts. So these things that we just talked about on the control side, at this point, I won't be messing with the air control that we looked at, and the volume of liquid control, because those should be set. Maybe a little micro adjusting once we see the finish go on the wood. But they should be in a pretty good position already. So, just watch as we go, and we'll get some finish on this walnut table.