Hi, I am getting ready to spray my firewall and undercarriage finally! ALl my friend has is HVLP guns, and i only have a 26 gallon 6CFM compressor, my friend also has a similar compressor, i am wondering if i can connect them together using a tee on one compressor and a hose going from the other to the Tee, and then from the tee out to the gun, there is a pressure guage on the gun so we can adjust for final air pressure? is this feasible? I really don't have any choice, and i know that even 12 PSI will barely be efficient, however we are not spraying an entire car. I already pieced the connections together but don't have the other compressor yet.

my friend just hooked up 3 air compressors together. Pretty much the only benefit he gets from that is the extra cappacity and the ability to run an extra motor to fill the air tanks back up quicker. I don't know if my post will help, i dont really know much bout AC

The problem is you will get allot more water in your system. If you can build a 620HP motor I would invest $600-800 in a good compressor tongue.gif

Well, we will have a water trap on each compressor so that should help/ i don't have 220 in my garage so buying a new compressor/110 volts would be a waste.

You want both traps after the two or however many compressors, that's what I do. No point in running it through a trap just to have it go through another compressor. Do the double filter after all compressors. Might want to run 220 to the garage as I did, it is really easy, you might need it for a plasma cutter or welder someday!

well the way it is going to be is like this; have one compressor; coming right out of the pressure regulator will be a water trap, then out of the water trap there will be an air hose that will travel to the other tank;. Now out of this compressor there will be a water trap coming right off the tank/pressure regulator just like the other one. Out of the trap will be a "tee" now this is where the hose from the other compressor will hook up to one side of the "tee" out of the other port on the "tee" will be the final air hose which will go straight to the spray gun where there will be a pressure guage. My main concern is if this will actually double the CFM? will this add both of the CFM ratings toghether? I would assume it will work but who knows! Any more help is great. P.s. also Since there will be a water trap right at each compressor i don't see the need to run two right before the final hose? make sense? thanks!

By ganging the two compressors together, you will effectively have twice the CFM.

Your assumption about the water traps is a little off. The process of air compression produces heat...significant heat especially in smaller compressors with relatively small tanks. In order to remove the moisture from the compressed air, it must first have the opportunity to cool down so that the moisture will be condensing to a liquid state. Until it does that, the water trap(s) won't be very effective. What that means to you is that the further away from the compressor outlet(s) you place the water traps, the more water they will be able to remove because the air will have had a chance to cool.

A better way to plumb the compressors would be to run an airline directly from one compressor to the other. From the second compressor, run a 25-50 hose and then install one or more water traps. (With small, hot-running compressors, only one trap may not be sufficient.) A regulator can be placed in the airline after the water traps. This would be a basic, minimum for a temporary set-up. More permanent installations could include metal pipe from the compressor to the water traps, etc.

Simply said, the further from the compressor, the more effective the water trap will be. At the same time, the more the air has been re-cooled prior to reaching the water trap, the more effective it will be.

We see similiar set ups in industrial plants. They will run mulitiple screw compressors to achieve the same thing. You will need to regulate the air right at each compressor, but don't bother to use a water separator/filter at this point. Run the lines to a common accumulator, either a storage tank or a length of steel pipe [ 3/4" - 1" steel pipe approx. 16' -20' long , longer if you can fit it is better ]. Install the filter/water seperator at the end of the steel pipe run, the steel pipe will act as a volume accumulator and also as a heat exchanger. The air will cool down in the steel pipe and effectively remove water vapor. Putting a water trap right at the compressor is useless. I have 1" sch.40 steel pipe mounted on the wall, going down 2 sides of the garage, total run before the water trap is about 30 feet from the compressor. I also istalled a pipe tee in the line with a pipe nipple facing down with a ball valve at the end for an additional water trap before the water separator. Even in the most humid conditions, my air supply is "dry". 2 small compressors still won't be as efficient as a larger one though. A large capacity single stage is good for most home based shops, a 2-stage is obviously better. The other thing that you will have to address is the electric supply. Each of the small compressors will draw 10 - 12 amps for a total draw of 20 - 25 amps. The safe limit for a 110VAC circuit is 20 amps on 12 gauge wire is 20 amps. Hopefully you don't have 14 gauge wire in there as it is only safe for 15 amps and will "overheat" if you try to draw more amperage through it. Unless these are running on seperate circuits, you are running the risk of electrical hazzard, that is if the circuits breakers don't trip anyway. If you have two seperate 110VAC lines into the garage of at least 12 gauge wire, you can easliy have one of these converted to a 220VAC 20 amp circuit by any electrician. 220VAC 20 amp will support most if not all large single stage compressors. If you are going to run a new line make it at least a 30 amp {10 gauge} or 40 amp {8 gauge} into a master disconnect with its own breakers and set up a sub panel in the garage to feed additional circuits as needed. Well worth the work, and not really that expensive to do.

Naturally you will get more volume of air by using more compressors.
Just connect the two together anywhere ahead of the regulators and like was said have the water trap as far away from the air tanks as posible.

You only want/need one regulator ahead of the gun but if you have two water traps it won't hurt to use them both.