HVLP with Turbine

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Advice on whether to switch from a siphon gun to an HVLP spray gun. May 17, 2005

I'm thinking of switching to an HVLP sprayer. My compressor is big enough to run the new gun's needs. I've only used the traditional, siphon feed guns, usually with a small cup size (10 oz.). I don't do a lot of finishing, so it has suited me well so far. I don't like fog in the air, and I don't like overspray. Plus, not wasting material sounds attractive. I usually rub out all of my gloss finishes, so "off the gun" isn't that important, however, I might like to go that way for my satin finishes. So, this is why I'm thinking of HVLP. I'm reluctant to change because I am used to what I've got going. But I am hopeful that I might be pleasantly surprised.

I noticed that the HVLP guns come in gravity feed and siphon cups. I'm inclined to go with the gravity feed as the cup sizes are more like what I'm used to, and it seems like there would be less trouble. I have never used a gravity feed, conventional or HVLP. I am intending this to be used for precat clears.

Forum Responses
(Finishing Forum)
From contributor D:
I predominantly use my HVLP setup over others because of the reduced overspray. It's not quite as low as an airless or an air assisted setup, but I feel it gives me the best control for the multiple tasks that I ask of it.

I mostly spray large jobs, which is why I choose to spray from either a 2 1/2 gallon or 5 gallon pressure pot. I save my cups for touchups, which I also use a HVLP for.

I am presently using 2 Accuspray setups and 2 Titan setups. 3 four stage systems and one compressed conversion system. The one thing I have found is the lifespan of a hot turbine varies dependent on the environment. I've had units last 8 years and I've had units last 8 weeks. Most of these units are not designed to stay on for hours of uninterrupted service. I find when I am spraying paneled walls and the unit is on for long periods of time, I need to be a little more aware of the servicing I give the unit. I have had hoses melt from the excess heat, turbine fans and impellers expand due to excessive heat and seize the motor. The number one complaint I get when working onsite with my turbines is the noise. It's basically only a vacuum, but it does add to the noise pollution on a construction site.

I spray everything with them. NC lacquer, precat, postcat, acrylics, vinyl sealer, conversion varnish, polys and on occasion, oil and latex paints. All with great results.

From the original questioner:
Have you had any experience with the HVLP gun/regular compressor setup? I would be going that route as opposed to the turbine. I understand that there can be advantages to both. Seems like most of the guys on this board use the turbine setup. The smaller guns suit me well as opposed to the pressure pot setups. I can spray one of our amplifier cabs down easily with a 7oz. conventional siphon feed gun. I don't use a lot of material during a finishing session. I'm looking mostly to increase quality with a new gun.

From contributor J:
A couple things I don't like about mine is the bulk of the hoses and the noise - mine sounds as if you're working next to a jet engine. Also, the heat that builds up after continuous use seems to cut down on the efficiency of the unit. And last, the heat also gets transferred to the coating and flashes off too fast, not to mention the hot hose in the summertime. I do like the hot air it blows for curing coatings, but just not as it's coming out of the gun. Mine is the Titan and maybe newer models are different (I think mine was one of the first ones out on the market).

From contributor C:
I have used two HVLP conversion guns, one gravity feed and I would not recommend it. They are very sensitive to viscosity and in lower temperatures, do not atomize well. I just converted to a pressure assisted Binks 1sl and find it infinity better. I do furniture and cabinets, so I don't need an outboard pressure pot. The 1 qt size is great and much better balanced and more easily maneuvered inside tight spaces than a gravity feed setup. I sprung for the regulator on the pressure assist and am glad I did - this setup will atomize almost anything with great finish quality.

From contributor A:
What do you intend to spray? Gravity guns are not the best things to use for insides of cabinets or for doing stools/chairs. Turbine units with bleeder guns are also a nuisance in these spraying conditions. If anything, look for a turbine rig that has a non-bleeder gun if you are going to get a turbine.

From the original questioner:
We spray amplifier cabs and speaker enclosures. We don't spray the insides or any area that is really hard to get to. Mostly, the surfaces are flat (facing up).

From contributor D:
I do have a couple HVLP conversion guns. My favorite is my Binks Mach1. It was my gun of choice when I had my shop and spray booth. I still use it today if conditions permit. I finish onsite and like the portability of my turbine carts.

If you are only spraying the outside of case goods, I see no reason why you wouldn't want to go to a HVLP conversion setup. I wouldn't consider it without a regulator on the gun for adjusting to the proper air flow.

Use whatever cup setup you are most comfortable with - either should serve you well. My thoughts would favor a gravity feed gun if you are using little amounts of finish. Siphon guns are a little finicky when you start running low on materials and tilt the gun (siphon tube) away from the material in the cup.

Make the switch, you'll be happy you did.

From contributor G:
I switched from Binks 7 air to Binks Mach 1 HVLP. The main issue was to save money on coatings. We did, but later the coatings manufacturer raised prices and we were back where we began.

HVLP guns seem to operate on the fringe of just enough atomization - input air approximately 43lbs is best. Being used to an air gun, you will probably at first not like the HVLP. But once you learn how to operate it you will save money and reduce fog. Excellent atomization produces fog, less atomization = less fog. You will find yourself basically using a 4 inch patten and spraying closer to the part. The gun kind of paints it on like a liquid brush.

My setup was: coating side - ARO stainless steel diaphragm pumps (there are cheaper) - fluid reg. (right on the pump) - gun. Air side: compressor - air dryer - air regulator - gun. Also air reg to input side of pump. We replaced 8 guns, adjusted to them (had resentment), then never looked back. Great finish, cleaner, lighter. The mach 1 is a good gun, but expensive. And I would guess it will work well with most delivery setups. Having the correct orifice makes a big difference - say stain vs top coatings. Those Binks guys can help. We also went with the flexible tips with some, but can't remember if with stains or tops. I would also consider the imports - but would want a satisfaction guarantee of some type.

From contributor M:
If you decide to get a conventional HVLP gun look at Astro. You can buy the gravity HVLP for about $80.00 at Spray Gun World. They sell different tips for about $30.00. I bought one of these with the 1.7mm tip and got an additional 1.4mm tip. I must say I can't believe how well these guns spray. I spray lacquer on my cabinets and in the summer I use the same gun for spraying paint for auto bodywork. I went back and bought a mini hvlp and it has really helped me inside cabinets. These guns don't use a lot of air either - your larger compressor would have no problem with these. I like this gun so well I'm going to get the same thing in a siphon feed next. If you check the auto paint forums, you will see these guns being praised. They are remarkable for the money.

From contributor O:
Try Binks Mach1 with 2qt. pressure pot. This should work well except for items that have silicone.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor K:
I have a CS 9100 Capspray 4-stage turbine with a siphon feed cap spray gun #4 tip set and the finishes that I am able to achieve for hand rails and doors is amazing the only problem that I have with the system is the system needs to be well maintained. As well the lacquer finishes take a little more practice and trust in the product that you chose to use as some produce a better finish than others. I always sand with 200 then 400 grit sand paper before recoating. There are about three coats of lacquer and then an old English oil rub and they look like glass. Itís sweet and simple. I like the comments made by others in this article they are very useful.