paint spray guns

I would like to get an inexpensive paint spray gun for spraying primer and enamel on metal objects. I already have a compressor and figure
that buying paint by the quart rather than by the spray can would be cheaper. But since I do not do a lot of painting, using spray cans might be cheaper. Harbor Freight , MSC, and Grainger are all within ten miles.
So what would anyone recommend. I am thinking in terms of one of the Harbor Freight conventional spray guns, but do not have a clue as to which ones work well. So does anyone have one that they like?
Should I consider a HVLP gun? The compressor that I have is only a 2 hp compressor, but a real 2 hp. Will not work on 120 volt circuit.
Also has anyone ever jury rigged a electrostatic spray gun?
Dan
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snipped-for-privacy@krl.org wrote:

I would only consider HVLP. Otherwise plan on painting your workpiece and everything else within 20 feet (my experience).
Look at the CFM ratings of the spray guns, and add in a fudge factor, vs what your compressor is honestly capable of. Even with a small compressor, you can still use it but you may have to let it catch up periodically.
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RB wrote:

If this is your first gun go HVLP. That way you don't have to relearn how to use a paint gun. The HF 47016 guns do a credible job. I have one that I use for spray fill and they seem to work pretty well. Not as good a final finish as my high end Binks but for the price of the tax on the Binks it does a good job. Make sure that if you buy ANY of the import guns you buy some spare parts to fit the gun when you buy it. Who knows what they will change in the next few years and make replacement parts impossible to find!
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What does "HVLP" stand for? My WAG is "High Volume Low Pressure" but a cursory google search doesn't confirm that.
-Frank
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wrote:

you are right, high volume, low pressure for example, http://woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM 4-559&search=&smode see the theory of operation, here: http://www.binks.com/upload/7b0bb727-3b8f-41ea-a9aa-cd283bf76e70/service/81816X.PDF
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On Thu, 18 Jun 2009 15:27:01 -0700, Frank Warner

Add "spray" to HVLP and Google will confirm your WAG as correct. But what is high volume, or low pressure? Not all kit billed as HVLP, notably that from HF, meets the criteria listed here: http://www.fujispray.com/what_is_hvlp.html
The HF offerings may satisfy requirements of the State of California. I have a couple of them and have found them completely satisfactory where autobody quality finish wasn't necessary.
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The greatest benefit of using a spray gun over aerosol paintcans, is that you can apply more durable coatings with a spray gun. I'm not referring to Imron or other high tech coatings, just a durable coat of enamel.
A paint gun isn't necessarily cheaper than paintcans, but real primers are going to allow better adhesion, and better choices of the proper primer for each job.
FWIW, the term HVLP is mostly used as marketing hype. Real HVLP systems work with only about 3 to 8 psi of air from a turbine, not a cheap paint gun attached to conventional air hose at 20-50 psi.
One of the best references for surface preparation and choices of primers and paints, would be a paint manufaturer's finishing or refinishing guide. It will advise you of the proper coatings and associated products.
A 2 HP, 2 cylinder single stage air compressor in good condition is adequate for most spraying jobs, up to overall refinishing of an average sized passenger vehicle.
About the only critical component of a compressed air system for spray painting, would be a good quality oil/air separator in the air line to essentially eliminate the moisture from the air supply. A properly plumbed black iron pipe air system will cool the compressed air and allow much of the moisture to drain back to the air compressor tank, and/or be trapped by drip legs in the pipe system.
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wrote:

I've just got an HVLP gun being delivered. Haven't gone all the way with a turbine driven setup, but hope improve over my conventional gun.
Overspray is a significant issue with conventional guns and HVLP should give less mess and more economy.
My compressor is 2hp and certainly doesn't struggle with my use of the old gun, should cope all right with the HVLP.
Mark Rand RTFM
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Mark Rand wrote:

Maybe. It's the volume that gets you. My compressor is a 6HP (I know, I know) Crapsman oilless on a 30-gallon tank. It had about a 75% duty cycle with a basic cheapo HF HVLP gun. I also tried a conventional gun (also HF) and fogged up the whole lot, but did not run out of air.
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On Tue, 16 Jun 2009 11:30:22 -0700 (PDT), " snipped-for-privacy@krl.org"

If you have air..and it appears you have more than enough..my absolute favorite for general light duty work is:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber
And they go on sale for about $9 regularly.
Gunner
"Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam"
Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno
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I have a binks gun, a high grade chinese copy, and a couple of HF guns - the HF ones will work fine for anything but the finest quality finsh coats - you have a little less control, but they are less than a tenth the price. Gravity feed is good, not siphon, you probably want a touch up gun, not a full sized one. You can manage overspray with a regular gun easily if you are careful with pressure (more pressure = more overspray) just as with HVLP. I have a 5 HP Quincy compressor - it of course easily keeps up.

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On Tue, 16 Jun 2009 11:30:22 -0700 (PDT), " snipped-for-privacy@krl.org"

You omitted two key details: size of workpieces and desired quality of finish.
If you want automotive-grade DOI (distinction of image, aka gloss) you need to buy good guns -- and good paint. But you said "enamel" so I'm guessing you seek a presentable, level finish.
For smallish workpieces, I agree with Gunner: the $13.99 import "jamb gun" he suggested from HF works OK and it's cheap enough to be regarded as disposable. It's a knockoff of the Binks jamb gun. A Binks it emphatically isn't, but still far better than rattlecans. I've used them for shooting primers and such, reserve my good guns for basecoat and clearcoat on automotive work. They work just fine for shooting enamel. They may spit when getting near empty. Good guns don't do that but it's an easy problem to avoid.
The difference between HVLP (or not) in small guns like this is minor. I have both, don't see much difference. The difference becomes significant with bigger guns shooting quarts of paint as in larger panels or whole cars.
I have this HVLP jamb gun from HF, have found it completely satisfactory for small jobs like bicycles, motorcycle gas tanks, etc: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?ItemnumberF719
I guess it does have less overspray than the non-HVLP jamb guns.
Advantages of a gun over rattlecans:
*greater variety of available coatings including two-part epoxies and urethanes
*considerably more substantial film per coat
*you can mix colors from different cans to get exactly what you want
*considerably faster
Disadvantage: you must clean the gun meticulously after each use. Not a big deal, a few minutes and a few oz of solvent, but you either clean the gun immediately after use or discard it when it doesn't work next time.
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The really good guns take more air than your little compressor will deliver. I've got a compressor similar in size, I've used the el- cheapo touchup guns from HF with good results, on-sale at $10 or less. Their "HVLP" conversion gun will also work but the poor compressor will run constantly. I don't consider it the equivalent of a real HVLP that uses a turbine blower, but it does cut down on the overspray. Get the gun stand when you get the gun. I've used both with shellac, two-part urethanes and oil-based wood finishes. For small jobs, I've got a Paashe airbrush, has very good control. Unlike cans, you DO have to clean all parts thoroughly with any of them. A body shop supply will have cheap(er) lacquer thinner just for that. Moisture and oil trap both needed, use new hose that's never had oil blown through it. I seldom use a spray can anymore, the reformulation since CA changed their VOC rules makes the stuff way too heavy and runny.
Another option, for parts that can take the heat, is powder coating. HF has a kit for that as do others.
Stan
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Thanks for all the good advice. I will be getting the touch up gun that Gunner recommended. The HVLP guns are probably worth the extra money to get more of the paint on where you want it, but I do not paint a lot and almost never anything very big.
Dan
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A common method to reduce overspray is to reduce the air flow or supply pressure to the spray gun.
This can be easily done by adding a simple small valve at the handle of a paint gun. It doesn't need to be a pressure regulator, just a simple 1/4 turn open/closed valve that will allow some adjustment of the air flow.
A common practice was to fold the air hose and squeeze with the free hand, just like shutting off the water flow from a garden hose (instead of walking over to the regulator to re-adjust the pressure temporarily).
Siphon cups require a certain amount of air flow to lift the paint up the delivery tube to the spray gun head, but the minimum amount of air flow is surprisingly low. YMMV, as I didn't use cheap paint guns when I was doing a lot of painting.
Gravity cups and pressure cups don't have the same minimum air flow requirements, but with all types of conventional spray guns, the atomization of the liquid paint is reduced at lower air supply pressures. High atomization is important for very high quality finishes (especially polychromatics/metallics), but doesn't matter much for basic corrosion protection.
None of these remarks matter if the paint isn't mixed properly.
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On Wed, 17 Jun 2009 12:46:15 -0700 (PDT), " snipped-for-privacy@krl.org"

I like gravity feed guns (where the paint container is at the top) rather than suction feed guns. I find them a lot easier to clean, although you will need to bend up some 6mm round to make a stand when you want to put the gun down, since obviously it cant sit flat on the table without a flat bottomed paint container underneath. Geoff
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