Need to learn about HVLP and air spray guns:

[speeder]

As some of you may know, I do house painting and various other renovation work including stripping, wood repair and staining/refinishing. I have never branched-out into cabinet work other than painting them, of course. I've been meaning to pick-up an HVLP sprayer w/ gun for years but for some reason never have. I've used them and had no problems but now I want to buy one.

Are they appropriate for small automotive applications, like painting wheels and other parts? Or do I need a regular air gun, like a Binks 7? Obviously, I would have to thin-down my materials to the consistency that these guns like but that is not a problem. I have a set of truck wheels that I would like to paint with industrial oil enamel that is normally used on railings and other metal, outdoor architectural applications. (Wrought iron, etc.).

I have a decent compressor already, so all I really need is the gun and some knowledge. That's where you guys come in.

Should have called-out Tim Hancock in the title, I hear that he's the resident Pelican paint expert.

[Zeke]

HVLP's come in a couple of varieties. I have both. The first one is a Wagner turbine powered thing with a garden sized hose providing the air. Not a bad machine for lacquers and thinned enamels. The newer water borne architectural paints don't spray as well with this unit.

The second one is a top load spray gun used with a conventional air compressor. Not that much different than your mentioned Model 7 other than less of a cloud of atomized paint.

As with any gun, the paint is the key. Vinyl acrylic house paints don't spray all that well compared to solvent based enamels.I think you'll get used to either if you experiment a bit.

Ask your dealer/supplier about different fluid nozzles, needles and air caps. I have a heavy material set up of those 3 parts that moves and atomizes heavier material as well as the smaller set up for clears like polyurethane. But, you can only go so far. They don't paint wall paint.

[speeder]

Thanks, Milt. I was thinking of using this only for painting metal w/ solvent-based materials, maybe some cabinet work as well when I get good w/ the gun. I just don't know much about them, ie. difference between top-feed (gravity) cans vs. suction cans, HVLP vs. air guns, etc...

I have a Binks Superbee airless that I never use anymore for painting houses. I'm thinking about painting wheels and maybe the inside of the bed of my old truck.

[BGCarrera32]

My advice would be to pick up one of the $150-ish DeVilbiss kits from Eastwood or somewhere. For primers (heavier build up stuff) you want a larger tip like 1.5-1.8 mm, less for a BC/CC type paints- 1.2-1.4mm.

I had a $350 Binks M1-G with a 1.4mm tip, and I thought it was a waste because I end up color sanding and buffing anyway. On the other hand I bought a $250 Sata touch up mini-gun and that is the cat's patoot. I would get something not too cheap, but there is no need to blow a ton of money on it either.

From Wikipedia:

HVLP (High Volume Low Pressure)

This is similar to a conventional spray gun using a compressor to supply the air, but the spray gun itself requires a lower pressure (LP). A higher volume (HV) of air is used to aerosolise and propel the paint at lower air pressure. The result is a higher proportion of paint reaching the target surface with reduced overspray, materials consumption, and air pollution. A regulator is often required so that the air pressure from a conventional compressor can be lowered for the HVLP spray gun. Alternatively a turbine unit (commonly containing a vacuum cleaner derived motor) can be used to propel the air without the need for an air line.

A rule of thumb puts two thirds of the coating on the substrate and one third in the air. True HVLP guns use 8–20 cfm (13.6–34 m3/hr), and an industrial compressor with a minimum of 5 horsepower (3.7 kW) output is required. HVLP spray systems are used in the automotive, marine, architectural coating, furniture finishing, and cosmetic[clarification needed] industries.

[look 171]

We run 3 Accuspray guns. One for Lacquer (I still like pre cat lacquer and use it a lot), the other with a larger needle for water base lacquer or poly. The last one is for paint like doors and cabinets. I like Accuspray is because you can change needle size in seconds and the guns are rebuildable. The turbine does not collect compressed air so there is no water build up that may ended up in the finish. I know there are filters but the other adv. to that is the the air actually comes out hot or may be warm so it drys the finish a bit. The gun can be dial so fine that you can spray the width of an inch of finish on a face frame. great for touch up work on the job. Most people now make a non bleed gun. this way you are not blowing dust all over the place. Make sure you buy a bleeder or else you can ruin your turbine. There's a Korean lady on La Brea that carries their parts. I just mail order everything and stock up.

Binks Mach 1 is a good gun if you have the compressor to drive it. It can deliver a lot of material on flat large surface like tall pantry sides. That gun is perfect for lacquer build-up. I saw a really nice up to date hvlp gun at the vendor a few months back. It was design by ex-engineers that worked on the Mach 1. I tink it was $300 for the gun. When my binks goes, that's the gun I like to have in the shop. You can get them from Louis and Co. We don't do much finishing anymore because it is too much work and I have to careful with the AQMD Nazi and the a couple of butt heads around our complex. I have my painter do it on the job. If he gets fine, it isn't so steep. He hasn't yet.

Jeff

[look 171]

Speed,

Where can you get solvent-base industrial paint? Is it in gallons or qts?

[speeder]

You can still get quarts anywhere, gallons are getting scarce in Los Angeles.

[look 171]

Know a place where they can mix custom colors without going to automotive paint suppliers. They are starting to get rid of solvent base paint also? I know the water base paint from places Dunn Edwards do not hold up for more then 5 years on exterior wood work. What do you have luck with?

[speeder]

Dunn Edwards still sells Syn Lustro in qts. AFAIK. The last time I checked, (maybe 6 months ago), my DE rep located plenty of gallons of SL in white mixing base outside of L.A. (Like Phoenix, maybe)?

Syn Lustro is oil-based industrial paint that is labeled for metal use, (AQMD thing), but it's the same old SL as always other than lower VOCs. It's great on exterior wood if prepped/primed/applied right. I guess that goes for any paint.

Ben Moore still sells exterior oil in qts., last time I checked. I think everyone does.

Need anything painted? I'm always looking for work.

[look 171]

Thanks for the tip.

No, no painting right now. I try to not get involve in bidding on exterior painting because it makes my final number seem lower unless its a higher end job where people have bucks and do not want to deal with the headaches. So many times these home owner come back with a lower number then what I have to shell out to my painter. I know their work is crap. I shall keep you in mind the next time. You do much lacquer work?

[David McLaughlin]

I use a regular gravity spray gun and a HVLP spray gun for painting small items at my day job (Lexington*Studios). I paint items as small as a 4"x4" clock to as large as 2'x4' toy boxes. I'm also shooting latex high hide house primers and latex paint. Because of the work I'm doing I don't worry about a little texture but with the right mixture I could shoot a super smooth surface too. With a solvent based paint the work would be even easier.

[Tim Hancock]

Denis,

I own and have used a variety spray guns over the years to paint several cars, airplanes, motorcycles, wheels ect. I have old school Devilbiss suction feed guns, a couple of small cheap suction feed trim guns, a couple of cheap gravity feed trim guns, a Binks M1G gravity feed, several cheap brands of gravity feed HLVP guns and a Croix turbine HLVP system.

The majority of my painting in the last 15 years has been with cheap gravity fed guns (One cheap gun in particular that I bought at a flea market at Oshkosh has painted at least 2 airplanes and 2 cars). I have sprayed lots of different primers including epoxy. I mainly have painted with urethanes like Dupont Imron, PPG Durathane and Nelson Fulthane but I have also sprayed Dupont Centari, PPG Delstar and a couple of types of base/clear systems with these cheap gravity fed guns with great results.

I hardly ever use my Croix turbine HLVP system as it just does not produce as good of results with urethanes IMO (I mainly have used it for spraying airplane fabric dopes). I got my Binks a couple years ago from work as the shop guys had mistreated it and they bought a new cheap gun to replace it. I cleaned it up and it works fine now, but it does not magically do a better job than the cheap gravity feed guns I have been using for years.

I have done some painting at work (when our machine painter was sick) with the cheap Harbor Freight gravity feed guns spraying Polane (similar to Imron) and they work just as good as my no name gravity feed guns at home. I would not hesistate to paint another Porsche or airplane with one. Typically sale priced at $14.99, I would simply buy one or two (keep one for spare parts or as a primer gun) and be done with it. Use a paint strainer when pouring mixed paint into the gun and be sure to clean the gun well after every use and it will serve you well.

When using these "HLVP" gravity fed guns, I always use higher pressure than called for to better atomize the paint (usually set my regulator to around 50-60 psi). Sure it wastes a bit more paint through overspray, but even though the paint is expensive, the huge amount of labor I put into the prep makes me not worry too much about wasting maybe $50 of extra paint when painting a car.

Here is a link to the Harbor Freight gun I have used at work without any problems... it will be just fine for occassional use spraying auto paints. 20 Oz. High Volume Low Pressure Gravity Feed Spray Gun





Here are some pics of some of just a few of my projects using a "cheap" gravity fed gun spraying Imron, Delthane, Fulthane, Delstar and Centari. I could get the same results using a $500 gun or a $14.99 gun. I am not a professional painter, but with careful prep and time spent learning/figuring out how much paint to lay down, one can turn out some nice work out of a home shop with inexpensive equipment.









Edit: I guess I never answered your question about oil based enamel.... Yes I have sprayed thinned down oil base enamel "tractor" paint with these gravity fed "HLVP" guns. It will work, but you have to play with it a bit to figure out how much to thin it. It takes forever to dry and therefore is not very forgiving in regard to runs/sags due to over application.

[gr8fl4porsche]

I have many spray guns. Airless, conventional, HVLP, gravity fed - you name it.

We tend to use the $20 cheap Chinese ones from Harbor Freight for most items except fine automotive finishes.

They work fine and when they wear out or get too dirty - into the trash they go.
We buy 5-6 at a time. They definitely put out the overspray, but if that is not a concern, go for it. Your wheels will turn out fine.