Todd or anyone else (about HVLP)

[aurelio alarcon]

I have a small 4.5 gallon tank, rated at 7.7 @ 40psi Porter Cable compressor. I would like to know if I can use a spray gun with this compressor to spray paint and other finishes? I know a complete system would be better, but I am trying to get the most out of what I have. Finances won't allow me to make such an investment at this time. But I would like to get a spray gun to do small jobs. I have found a HVLP spray gun requiring 7.0 scfm @ 40 psi. Additionally, I found some guns that come in pint size and are gravity fed. I know very little about spray guns and what is required of them. Can anyone help?

[Eric Apple - Central IN]

I have a small 4.5 gallon tank, rated at 7.7 @ 40psi Porter Cable compressor. I would like to know if I can use a spray gun with this compressor to spray paint and other finishes? I know a complete system would be better, but I am trying to get the most out of what I have. Finances won't allow me to make such an investment at this time. But I would like to get a spray gun to do small jobs. I have found a HVLP spray gun requiring 7.0 scfm @ 40 psi. Additionally, I found some guns that come in pint size and are gravity fed. I know very little about spray guns and what is required of them. Can anyone help?


I actually prefer to use the conversion guns that run off of a compressor. 7.7@40psi is plenty to run many many guns. You may not be able to spray "paint" as in latex with a small volume of air without a pressure fed gun. However, clear finishes (varnish, shellac) and dye stain with a gravity fed (cup on top gun) is very possible. I suggest that you checkout homesteadfinishing.com and give them a call with your requirements.

[Todd Burch]

Hi Aurelio.

If your specs are correct on the compressor, and the specs for the HVLP gun coincide, then you should be fine.

In a prior life, I sprayed SEVERAL automobiles with a conventional gun and a Sears 2HP compressor with a 20 gallon tank. (Many times I had to wait for the compressor to catch-up, but it worked!)

The gravity guns are easy to clean. Siphon cups are easy, but not as easy. Pressure rig setups (2-quart cups or 2.5 gallon pots) are more geared towards the higher-volume user. Both gravity and siphon styles are more difficult to maneuver on completed pieces or inside/under cabinets and the like.

Guns are purchased with tips based on what you will be spraying. For instance, the tip for spraying oil based enamel would be different than what you would use for spraying a toner.

Todd.

[Jim Becker]

"Can spray" with your current compressor and "should spray" with your current compressor are two different questions. Why? Let's assume that the unit can provide enough air (SCFM) to operate your gun. With a very small tank it's going to be running constantly, which not only is noisy, but also can cause a significant moisture problem. Even with a good filter that will be challenging. Your choice of finish will also matter...water based finishes will probably work better for you with that compressor than solvent-based--again due to the potential for moisture in the air stream, despite filtration.

Most HVLP conversions guns will be "happier" with at least a 20-30 gallon tank on the compressor. Even then, they will run pretty frequently. (I know that from experience as my current compressor is a 20 gallon unit and I use a Wagner HVLP conversion gun for all my spraying) I'm not saying this to discourage you from aquiring and using an HVLP conversion gun; 'just trying to help set expectations. Those small 4-5 gallon compressors are best suited for nail guns and the like where actual air usage is a lot less than the constant stream demanded by spraying finishes.

[Jason Roehl]

I have a small 4.5 gallon tank, rated at 7.7 @ 40psi Porter Cable compressor. I would like to know if I can use a spray gun with this compressor to spray paint and other finishes? I know a complete system would be better, but I am trying to get the most out of what I have. Finances won't allow me to make such an investment at this time. But I would like to get a spray gun to do small jobs. I have found a HVLP spray gun requiring 7.0 scfm @ 40 psi. Additionally, I found some guns that come in pint size and are gravity fed. I know very little about spray guns and what is required of them. Can anyone help?

Aurelio, I think I have the same or a similar PC compressor. I have used it to spray with fine results. There are a couple things to keep in mind, though. A conventional spray gun will result in ALOT of overspray. Cover everything except what you want to spray, and you'll be fine. As some of the other guys mentioned, a conversion HVLP gun would be better suited, but you'll spend a few more bucks on one.

Jim mentioned the moisture issue--there are moisture filters on the market, readily available. I've not had a problem, even using my compressor for extened periods of time with a filter.

As for the extended use, my compressor (and probably yours, check the manual) is rated 50% duty cycle. That means that out of every hour, you can only use it for 30 minutes. If you are spraying constantly, with only brief let-offs of the trigger, the compressor will run almost continuously, so make sure you're at a good stopping point within 30 minutes (ideally 1 coat), then take a break for 30 minutes or more and do something else.

Hope this helps.