Replies

1. 
   Andrew | May 12, 2003 10:10pm | #1

   Your friend is right, but, it is entirely possible to run an hvlp gun with your compressor. Some of the better guns don't need much air at all, and compressors will put out more cfm's at a lower pressure. Worst case scenario is that you have to stop every now and then to let the compressor recharge, but as long as your not in a production situation it will be fine.

   Any compressor you find at a hardware store is likely to be rated at peak hp. Once you start looking at industrial compressors (ingersol rand, quincy, kellog), then you'll see honest ratings for hp and air flow.

1. 
   cutter | May 12, 2003 10:48pm | #2

   Thank you very much!

   What do you suggest for most "bang for the buck" in an HVLP gun for my compressor?

   In the non-HVLP type, have you seen the "Critter" - about $50 - that uses mason jars for the paint reservoir.  Seems to be popular.  Is it worth considering for non-critical work?  I like the idea of the mason jars for various paints, and the fact the feed tube is all you really need to clean.

1. 
   TomT226 | May 13, 2003 02:25pm | #5

   http://www.homesteadfinishing.com for exellent HVLP conversion guns.

1. 
   cutter | May 13, 2003 06:43pm | #6

   Thanks everyone for the helpful advice.

1. 
   riverr1 | May 14, 2003 03:54am | #7

   Andrew,

   I could be wrong, but actually aren't most of the top of the line HVLP's running at a high CFM? Most good manufacturers make a middle of the road gun the runs on less air, but the good guns start at about 14 or 15 CFM, and the top of the line guns, some of them push 25 to 30 cfm.

   BTW, IR does not use the "special" hp rating.

   Don

2. 
   Andrew | May 14, 2003 05:33am | #8

   Yes Don, some good HVLP's do use a lot of air, however I've never heard of anything other that a turbine powered HVLP needing over 20 cfm.

   From what I understood talking to my local finishing guy, the low end guns aren't nearly as efficient with air, so they always need higher cfm's. Then there are the LVLP guns, which most people will just refer to as an HVLP gun, (so they tend to get mixed up together) that can run on less than 5 cfm. When you get into "real" HVLP guns, air requirements depend on your set up. Pressure pot systems need more air flow than a siphon feed or gravity feed gun. My friend has a very nice Graco gun with a pressure pot, and he only needs about 12 cfm to run it (he ran it from a 3 hp ingersol rand compressor ) and it only struggled a little doing production spraying. If it was a siphon feed gun it would be even less. It was my understanding that HVLP came about to

   1) reduce overspray and waste and

   2) to eliminate the need for a huge air compressor to spray finishes. You'd need a pretty big compressor to deliver 30 cfm even @ 40 psi.

   What you may be thinking of is the CFM at the tip of the gun. HVLP guns are designed to further reduce air pressure and increase the air flow inside of the gun, which is why you can have 40 psi in and 10 psi coming out at the tip. Sorry if I was confusing in my first post.

   And yes, I'm aware that ingersol rand uses honest hp ratings.

   Andrew

3. 
   riverr1 | May 14, 2003 06:54am | #9

   Andrew,

   I agree that they ain't common, but Graco makes a gun the operates at at 58 cfm.

   When I  bought my gun (sharpe) I was willing to drop the money for a good one, but then I found out what I would have to drop for a compressor. Well, the rest is history. The high end Binks and Sata operate at 25 to 28 cfm. The industrial stuff, way over that.

   Yea, I assumed you knew IR posted an honest hp. Wasn't really posting that bit of info for you or anyone else, but for general FYI to whoever.

   Don

4. 
   Kevin | May 15, 2003 08:41pm | #10

   I've got a DeVilbiss GTI gravity gun (which is an HVLP gun). According to the service bulletin it will produce 10 psi at the tip with 30 psi gun inlet pressure. So... using that as a baseline of what's coming into the gun... I read further down the bulletin that with the #100 aircap the air consumption for the GTI is 16 SCFM at 10 psi air cap pressure. With the better atomizing #2000 air cap (I have both) the air consumption is 15 SCFM at 10 psi air cap pressure. According to the service bulletin, drops in air pressure is a bigger problem for this gun that drops in CFM. So... reading inbetween the lines a bit I deduce that a compressor that is capable of supplying a steady 18 CFM would be more than sufficient to feed this gun.

   As an aside... I bought this gun in a pawn shop for $73 in excellent condition. That was a couple years ago and at the time this same gun was retailing locally for about $450. Mine is an early English made model, though. DeVilbiss makes all of them in Taiwan now. So, I imagine that were I to sell it I could get slightly more for it than for a used Taiwanese made GTI. The relevant point I'm trying to make here is that it doesn't hurt to cruise the pawnshops once in a while. That said... I absolutely love this GTI. It is a fantastic gun! I also have a cheap copy of a SATA gravity gun (also an HVLP) as well as a 2 gallon Binks pressure pot with a standard DeVilbiss JGA gun attached. The pressure pot/JGA set up is worth more... but, I'd rather lose that than my GTI - it's no contest really. The GTI is my pride and joy. LOL

   Regards,

   Kevin

2. 
   forestgirl | May 12, 2003 11:08pm | #3

   I think the critical spec for compressors is CFM at given pressures, not horsepower.  Whatever tool you connect will have certain air flow and pressure requirements, and your compressor needs to be able to provide that.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

3. 
   Paul_Snyder | May 12, 2003 11:43pm | #4

   Very few compressors tell you the "working" horsepower or actual CFM. They like you provide the numbers that sound the best. Some of the better brands (much more expensive), provide real numbers.

   FG has the key piece of info - how much air, in CFM, does the compressor supply? With that number in mind, you can select a spray gun that will work with your compressor. Some spray guns need 20 CFM and some as low as 1 CFM (touch-up gun).

   The Wagner HVLP spray gun is a good buy at $130. It will operate with a compressor as small as 1.5 - 2 HP since it only needs about 5 CFM to spray well. A quick search on google will produce some retailers for the spray gun.

   Paul