Follow up to paint gun question

[aurelio alarcon]

Ok, let me see if I got this correct. I can use a HVLP spray gun as long as the rates of both coincide, right? Or I can use a regular spray gun as well. But I really should have a larger capacity compressor tank or my compressor will constantly kick on. I would assume that this is not desirable. I have looked at a small garavity type fed pint size spray gun that said that it was for touch ups and a siphon type quart size gun that said that it was HVLP. I am not sure what you guys are talking about when you mention "conversion". If I use this HVLP spray gun system do I need something other than the gun and the compressor-- some type of converter? Well, I appreciate all your help. I can see that I need to do more research. In addition to what I just metinoned, I need a filter as well I take it?

[Jason Roehl]

Ok, let me see if I got this correct. I can use a HVLP spray gun as long as the rates of both coincide, right? Or I can use a regular spray gun as well. But I really should have a larger capacity compressor tank or my compressor will constantly kick on. I would assume that this is not desirable. I have looked at a small garavity type fed pint size spray gun that said that it was for touch ups and a siphon type quart size gun that said that it was HVLP. I am not sure what you guys are talking about when you mention "conversion". If I use this HVLP spray gun system do I need something other than the gun and the compressor-- some type of converter? Well, I appreciate all your help. I can see that I need to do more research. In addition to what I just metinoned, I need a filter as well I take it?

My apologies, Aurelio, for being as clear as mud. Traditional HVLP uses various types of turbines for their atomizing air (think vacuum cleaner in reverse--it's about what it sounds like, too). This air is pushed through a larger hose, maybe 1" inner diameter. Then, the fluid is moved into the gun in one of two ways--by siphon off the large volume of air, or by pressure through a second hose and a small compressor. Some stand-alone HVLP units have the very small compressor onboard with the turbine.

Several years ago, somebody outlawed the use of conventional spray guns used with a compressor (for commercial purposes only, I believe), because of the low transfer efficiency, which put lots of spray mist and thereby, solvents, in the air. This led to the popularization of "conversion HVLP" guns, which are set up to convert the higher pressure air from a compressor to a lower pressure for atomization. This reduces the airspeed at the tip, resulting in less "bounce-back" and a much greater transfer efficiency.

You can usually tell the difference between a conventional cup gun and a conversion gun by looking at the air holes around the tip. A conventional gun will typically have 4-6 small holes. A conversion gun will have those same holes, plus usually a "donut" hole directly around the fluid tip that allows for a large volume of air to pass at low pressure.

[aurelio alarcon]

My apologies, Aurelio, for being as clear as mud. Traditional HVLP uses various types of turbines for their atomizing air (think vacuum cleaner in reverse--it's about what it sounds like, too). This air is pushed through a larger hose, maybe 1" inner diameter. Then, the fluid is moved into the gun in one of two ways--by siphon off the large volume of air, or by pressure through a second hose and a small compressor. Some stand-alone HVLP units have the very small compressor onboard with the turbine.

Several years ago, somebody outlawed the use of conventional spray guns used with a compressor (for commercial purposes only, I believe), because of the low transfer efficiency, which put lots of spray mist and thereby, solvents, in the air. This led to the popularization of "conversion HVLP" guns, which are set up to convert the higher pressure air from a compressor to a lower pressure for atomization. This reduces the airspeed at the tip, resulting in less "bounce-back" and a much greater transfer efficiency.

You can usually tell the difference between a conventional cup gun and a conversion gun by looking at the air holes around the tip. A conventional gun will typically have 4-6 small holes. A conversion gun will have those same holes, plus usually a "donut" hole directly around the fluid tip that allows for a large volume of air to pass at low pressure.
First of all, thank you very much for clarifying this. I did notice that the gun that I was looking at did mention "large holes". Secondly, would you recommend a spray gun? Perhaps the one that you use or one similar? You did mention that you use a compressor similar to mine. Finally, if nothing else, could you point me in the right direction as far as specs, etc. ?

[Jason Roehl]

First of all, thank you very much for clarifying this. I did notice that the gun that I was looking at did mention "large holes". Secondly, would you recommend a spray gun? Perhaps the one that you use or one similar? You did mention that you use a compressor similar to mine. Finally, if nothing else, could you point me in the right direction as far as specs, etc. ?

Well, I don't have a conversion HVLP gun, so I can't recommend one there. The conventional one I use is just a $45 Coleman gun. It was the most expensive Coleman that Menard's sells (it was rated for automotive finishes), and it has served me well.

Which compressor do you have? Mine is the 3hp/4gal twin stack, rated at 135psi max, and 7.7cfm@40psi and 5.3cfm@90psi. CFP23400S, I think.

[Phil Phelps]

Aurelio, here are a couple of guns I use. The red one is a Binks BBR siphon gun. One of the best I've ever used. Lays down a finish as fine as you'll ever want. Overspray? You bet. The other is a "knock off " of a Croix conversion HVLP. The "spacer" between the handle and the inline regulator is a porus cylinder that allows ambient air flow. You see the difference between the guns right away. The big difference is this. HVLP produces less air at the tip, resulting in less overspray. It also delivers much more material. You have to get used to this, or you'll have runs everywhere. Much less overspray with the HVLP, but, you'll still need a spray booth, or wide open spaces, to use either. The HVLP conversion gun needs a lot of air to work properly. I set my compressor regulator at 80psi, and adjust my inline regulator for best operation for the material I am using. It won't spray at 30psi like the siphon gun. You can get away with a smaller tank with the siphon gun. I haven't used a compressor smaller than 30 gallon. The best gun? I deal with a pro supplier, but I can tell you the age old saying, "you get what you pay for". A good HVLP will cost you about $350 without the extras, inline reg., cups, etc. I really can't see spraying either in a shop with no exhaust equipment. And let me add these two things. The HVLP is no good for latex paint. I don't like watering down any latex for spraying, anyway. Let alone the HVLP. Shop for your equipment at a spplier of spray equipment. Good luck. Hope this helps.

[Jim Becker]

Secondly, would you recommend a spray gun? Perhaps the one that you use or one similar?

I have a review of the Wagner HVLP Conversion Gun that I use on my site. It's a very nice gun for a very reasonable price and is pretty easy on the compressor side of things. I run it at 40 PSI from the compressor and between 10 and 15 PSI at the gun's regulator.

[aurelio alarcon]

Well, I don't have a conversion HVLP gun, so I can't recommend one there. The conventional one I use is just a $45 Coleman gun. It was the most expensive Coleman that Menard's sells (it was rated for automotive finishes), and it has served me well.

Which compressor do you have? Mine is the 3hp/4gal twin stack, rated at 135psi max, and 7.7cfm@40psi and 5.3cfm@90psi. CFP23400S, I think.here are the rates of mine. It is the 3151 Job Boss

Lubrication = Oil-Free
Tank Size Gal. = 4.5
HP (Peak/Run)3.5/1.6
Max. PSI = 150
Air Delivery @ 40 PSI = 7.7 SCFM
@ 90 PSI = 6.0

[Jason Roehl]

here are the rates of mine. It is the 3151 Job Boss

Lubrication = Oil-Free
Tank Size Gal. = 4.5
HP (Peak/Run)3.5/1.6
Max. PSI = 150
Air Delivery @ 40 PSI = 7.7 SCFM
@ 90 PSI = 6.0

Ahhh...is that possibly the one with the extendable handle and the tires? I've been drooling over that one since it came out. Mine's just a tad heavy to be carrying around, but I do it anyway.

[aurelio alarcon]

Aurelio, here are a couple of guns I use. The red one is a Binks BBR siphon gun. One of the best I've ever used. Lays down a finish as fine as you'll ever want. Overspray? You bet. The other is a "knock off " of a Croix conversion HVLP. The "spacer" between the handle and the inline regulator is a porus cylinder that allows ambient air flow. You see the difference between the guns right away. The big difference is this. HVLP produces less air at the tip, resulting in less overspray. It also delivers much more material. You have to get used to this, or you'll have runs everywhere. Much less overspray with the HVLP, but, you'll still need a spray booth, or wide open spaces, to use either. The HVLP conversion gun needs a lot of air to work properly. I set my compressor regulator at 80psi, and adjust my inline regulator for best operation for the material I am using. It won't spray at 30psi like the siphon gun. You can get away with a smaller tank with the siphon gun. I haven't used a compressor smaller than 30 gallon. The best gun? I deal with a pro supplier, but I can tell you the age old saying, "you get what you pay for". A good HVLP will cost you about $350 without the extras, inline reg., cups, etc. I really can't see spraying either in a shop with no exhaust equipment. And let me add these two things. The HVLP is no good for latex paint. I don't like watering down any latex for spraying, anyway. Let alone the HVLP. Shop for your equipment at a spplier of spray equipment. Good luck. Hope this helps.
hmm, conventional or siphon or hvlp....I'll check them all out. But I'll tell you what kiddos, that 45 dollar coleman is starting to sound better and better....hmmm. I will absorb all of this info...After receiving some of you guys input, Jason's in particular, I read an article concerning the hvlp method, it's origins, etc. at Fine Woodworking and now have a better grasp...er...I think. Eco, Waste, safety, etc. They even made reference to someone using this type of method that was included with a vacume of all things. Of course, progress has been made. Just enough progress, I might add, to leave me somewhat bewildered. This is why I find woodworking and it's accompaniments so interseting!

[aurelio alarcon]

Ahhh...is that possibly the one with the extendable handle and the tires? I've been drooling over that one since it came out. Mine's just a tad heavy to be carrying around, but I do it anyway.
that is the one. It is so portable. It's a sin!

[aurelio alarcon]

I have a review of the Wagner HVLP Conversion Gun that I use on my site. It's a very nice gun for a very reasonable price and is pretty easy on the compressor side of things. I run it at 40 PSI from the compressor and between 10 and 15 PSI at the gun's regulator.
website! Your website is excellent as is the article on the paint gun. I have bookmarked your site and will absorb as much as possible! Thanks