hvlp or lvlp

priorinapriorina Member Posts: 6

with the order to leave the spray cans, I bought a small compressor, 8 bar/max with tank of 8 litres along with a gun HVLP 1.4. The compressor has a gauge regulator air outlet which set up to 1bar/14.5 psi as recommended for the activator, but the gun does not spray well are many drops. To atomize I have to put it on 2.5-3 bars/30-40psi. I am baffled because in the videos of Jim looks a good misting with 14.5 psi. Maybe I need a gun LVLP? You think? Thank you.


  • WileECoyoteWileECoyote Member, Moderator, Business Ninja Posts: 7,520 El Moderator
    You rate the compressor off of CFM or LPM, not pressure. Most guns take a large volume of air, that a small compressor cannot produce. Initially there is enough air, but the supply drains down incredibly fast, and your pattern changes (like what you are describing)
  • NotSoFastNotSoFast Member, Moderator Posts: 3,535 El Moderator
    I hate to say it, but that compressor seems way too small. We have a 60 gallon (227 liter) and it's still constantly kicking on while spraying. With that said, the LVLP would probably be better since otherwise, you will lose pressure and the motor will kick on after about 2 seconds of spraying.

    What gun do you have? What does your spray pattern look like when sprayed for three seconds on a piece of cardboard. Very few guns atomize thin liquids like activator well at the low pressure required. They are made for 30-60 psi and thick liquids like paint and primer.
  • priorinapriorina Member Posts: 6
    Hello guys,

    thank you for your replies. Attached a video with my little equip to activate. As a beginner I'm making mistakes. The first, as seen in the video, is that I set the gauge output to 1 bar/14.5 psi without pulling the trigger of the gun and therefore the atomization were drops and faulty. Then you can see that I put the gauge at 60psi but when shooting the gun, the working pressure is correct 1bar/14.5 psi. It can be seen that when the engine has started the flow of air is not less than 14.5 psi and holds steady.

    Now if I have a range of fogging normal. Use universal solvent to adjust the fan on a piece of paper and do several passes with different configurations. Which think that is the most suitable?

  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,333 El Moderator
    Man that's a tiny compressor... But your pattern looks pretty darn good overall. Pressure seems a bit high. You will want to set the pressure on your gun while the trigger is pulled.
  • WileECoyoteWileECoyote Member, Moderator, Business Ninja Posts: 7,520 El Moderator
    WAY too much air pressure, and that compressor is WAY undersized. As soon as it kicks in, you already know your pattern is changing.

    Stop being so concerned with pressure on gauges, they essentially mean nothing. Set your fluid flow low, and adjust your air to the minimum pressure to break up the stream completely. The fluid flow is set to the size of your piece, the air is set to break up the fluid.

  • priorinapriorina Member Posts: 6

    doing a first test with the gun doing only one pass. As you can see in the photo, holes appear in the piece that make us think little activity, but the holes started to come out with the sheet in the water after activating it before submerging the piece.

    The gun has no traces of grease after checking it, I do not have a humidity filter (it has to reach me) but the compressor tank does not have water. The spray seems correct. What could it be?

  • WileECoyoteWileECoyote Member, Moderator, Business Ninja Posts: 7,520 El Moderator
    Underactivation. https://k2forums.com/discussion/10060/troubleshooting-your-first-few-dips#latest

    Typically caused by improper gun set up, or not enough passes. That sort of film is going to require a lot more activator. Try it again, but make 3 passes instead of 1 with the same speed
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