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  • Spray guns

    I have a cheap Harbor Frieght spray gun that I've used on a couple of projects and haven't really been pleased with the results. It has a cup on the bottom and has to siphon the material up into the gun. I am thinking of getting a gravity fed gun or a system that has a "pot" that the material is put in and then the compressor is hooked up to it. I don't have a lot of experience with spraying and would love to hear from those of you that have more experience than I do.

  • #2
    Re: Spray guns

    Several issues need to be answered.

    Capacity of air compressor, type of painting to be done.

    You can get quality guns in both siphon and gravity feed. Gravity feed guns generally are hvlp.

    If you want to paint latex, get an airless.

    A more expensive gun will probably do a better job. Get one from a local auto paint store. Those guys can talk to you about tip sizes, pressure, volume, etc.

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    • #3
      Re: Spray guns

      The 2 quart pressurized pots that can hang on your belt are very handy. With only hoses going to the gun, it is easier to get into tight spaces, and you can turn the gun upside down, sideways, etc with no change in fluid feed or spillage and no need to turn the air cap to change the direction of the fan pattern. Very handy in spraying furniture, cars, etc. With the pressure feed or gravity feed, you can lower the air pressure (which also reduces overspray), and also run your coatings a little thicker, meaning less coats and possibly better flow out.

      That said, if you are spraying a water-based heavy pigmented coating like latex house paint, an airless is about the only thing that will atomize it, and it still may need backrolling. I have sprayed it with a binks model 7 and a pressure pot, but had to backroll do get a decent finish.

      JMTCW

      Go
      Practicing at practical wood working

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      • #4
        Re: Spray guns

        I have looked into the pressure pot systems more and they seem inticing. I would be using it to spray lacquer, that's about it.

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        • #5
          Re: Spray guns

          Binks and DeVilbiss sell them in a variety of sizes, but they are a bit expensive. If you are doing a lot of spraying, they are well worth it, though. I have not looked lately, but imagine there are cheaper alternatives out there. With lacquer, you won't need much pot pressure to get the fluid to the gun (only about 5 psi) unless you are working a long distance from the pot.
          They also sell pressurized 1 qt cups that attach directly to the gun (They have a pressure guage and manifold where the air supply connects to the gun, and a small pressure tube that goes to the cup. I do not recommend this, tho, because you lose the ability to turn it upside down or on its side when the fluid gets low (the pickup tube will rise above the fluid level) and you still have that big cup getting in your way in tight spots.
          There is one downside to the 2 qt pots I have used. The top screws onto the cup portion, and both are aluminum. I have had them seize up where it takes a strap wrench to unscrew it. Tighten it only enough to hold pressure and pick up a plastic strap wrench to have on hand if you need it. Also, make sure you bleed the pressure off the cup before opening it.
          One other tip if you have not used a pressure pot before. If you get trash around the fluid needle while spraying, it will not fully close, so the fluid will keep coming out in a little stream when you let off the trigger. I usually keep a coffee can handy to direct the nozzle into while I get the pressure off the pot. It pays to keep your equipment clean and strain any questionable material when filling the pot.
          Lacquer is one of the easier coatings to use from an equipment cleaning standpoint, so you shouldn't have any problems.

          Go
          Practicing at practical wood working

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          • #6
            Re: Spray guns

            I have used the pressure pot system for nearly 30 years,

            the biggest problem I have encountered, is not being able to get the material hose as clean as I would like to, and if your not using it daily, (when I was building cabinets no problems as were spraying nearly ever day, I jsut put the gun a small bucket of lacquer thinner some times paint thinner mix, (to slow down the evaporation) at night and all you had to do was pick up the gun and spray, as the material would not dry out in the pot, (now it would if left in the hose for long periods of time as the hose is not as tight as one would think and the solvent would permanent it way through the hose). but great for over night or week end.

            but when you put it away for some time it seems like I would always get some flakes that would be coming out of the hose, from dried lacquer that I could never entirely get out, the lacquer flakes mess up the gun some but enamel paint flakes mess up the project.

            I live in farm country, so I started to use a hose call "EVA hose rated for NH3 use", NH3 is use for fertilizer that is an ammonia gas, it is a semi clear hose and it is relative cheap, and is 3/8" in size, and tough as nails, as when it is used to apply NH3 it is normal about -33C below zero. usually good for over 75 pis, it is a harder but still flexible plastic than vinyl hose. It is cheap enough to toss it and start out with a new clean hose nearly ever project. last time I bought a material hose it was about $35 for 15 foot, and that was 15 years ago, so I have no idea what they are now, but at .22 cents a foot, a hose is $3.30 for 15 foot of hose, it holds up to lacquer very well.

            some possibilities. (sites listed for reference)
            http://www.nstock.biz/asp/product.as...rchFor=&PT_ID=

            http://www.murrayequipment.com/dyncat.asp?SGroup=EVA Tubing 3/8 Inch

            http://www.google.com/search?tab=iw&...q=EVA+nh3+hose

            Caution: when ever spraying lacquer or any solvent based product, extinguish all open flames any where near the work area, (pilot lights and other)
            Last edited by BHD; 05-28-2007, 11:39 AM. Reason: typo
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            • #7
              Re: Spray guns

              Being pretty new to woodworking, and thus new to finishing, I'm dissatisfied with the results when applying polyurethane via brush to some cabinets I'm finishing up. I'd much rather spray it on. While the aerosol versions of polyurethane have worked well for a couple of projects, I'm wondering about buying some sort of sprayer for applying the final finishes (not latex).

              I have a smallish pancake compressor with a pretty low CFM (2.6 at 90 psi) Is there any sort of sprayer that would work for something of this size?

              Any thoughts on something like this Black and Decker Airless Stainer?

              This is all for low-volume household projects, preferably less than, say, $150.
              Last edited by steveKane; 05-28-2007, 10:54 PM. Reason: (minor edits)

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              • #8
                Re: Spray guns

                I use an inexpensive ($50) HVLP - gravity fed unit from Rockler for all my wood projects. I'm sure there are better systems, but I have no complaints about this one.

                http://www.rockler.com/product.cfm?p...55&filter=hvlp

                I usually run it at 35 psi and get nice results. Not sure what your compressor will produce at 35-40 psi, but the gun needs at least 7 cfm.

                Hope this helps a little...

                Steve



                Originally posted by steveKane View Post
                Being pretty new to woodworking, and thus new to finishing, I'm dissatisfied with the results when applying polyurethane via brush to some cabinets I'm finishing up. I'd much rather spray it on. While the aerosol versions of polyurethane have worked well for a couple of projects, I'm wondering about buying some sort of sprayer for applying the final finishes (not latex).

                I have a smallish pancake compressor with a pretty low CFM (2.6 at 90 psi) Is there any sort of sprayer that would work for something of this size?

                Any thoughts on something like this Black and Decker Airless Stainer?

                This is all for low-volume household projects, preferably less than, say, $150.

                Comment

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