TheCoatingStore.com

Results 1 to 10 of 10

Thread: Hi everyone, Newby here with questions

  1. #1
    Join Date
    Mar 2021
    Posts
    6

    Default Hi everyone, Newby here with questions

    Don't be too hard on me, ok? I know I don't have the right equipment to do this, but I gotta try. This is my old 95 Ranger. Drives good but it is needing paint and It does not matter how it looks. My first question now is what do you guys set your compressor psi to when you are painting hvlp?
    It is a 20 gal tank

  2. #2
    Join Date
    Mar 2021
    Posts
    6

    Default

    I guess what I am asking is does it matter what the psi is at the compressor since it will be regulated at the gun?
    Will turning it down at the compressor help with by not making it cycle so much?

  3. #3
    Join Date
    Mar 2021
    Posts
    6

    Default

    I have 24ft of hose, then the water separator, then the 50ft hose on the reel. I have a disposable moister filter on the gun. The old truck still runs good but it beginning to get a lot of mostly surface rust.

  4. #4
    Join Date
    Nov 2006
    Posts
    2,135

    Default

    I donít think you can paint the entire truck at one time but you can paint sections and stop and wait for the compressor to catch up. You will have to watch the pressure gauge at the gun. If you have a regulator on the wall then set it at 80 or so and set your gun pressure with the trigger fully pulled at what the manufacturer recommends, maybe 23 PSI or so. When your tank pressure falls below 80 then your gun pressure will also start dropping too and causing the gun to stop fully atomizing the paint. The paint will go on thicker and cause solvent pop to occur even hours after you stop painting. This isnít the best way to paint because the paint you apply first will become dry before you are done spraying and the over spray in the air will fall onto that dry paint and mess up the shine. One type of work around is to mask off smaller sections and paint in several sessions. I did that before I got my big compressor. It works but color match between sessions can become a problem with metallics. Solid colors not so much.

    Bob K

  5. #5
    Join Date
    Nov 2005
    Posts
    45,326

    Default

    A 20 gallon compressor is quite small for spraying. In most case we recommend a 60 gallon or larger unit. But like Bob said you might be able to paint it in sections and with many vehicles that's what we do even when the compressor isn't an issue.

  6. #6
    Join Date
    Mar 2021
    Posts
    6

    Default

    thanks guys for being so helpful. My brother just brought over another water separator and a couple more guns to practice with. Well...will it help to have TWO water separators????
    I am not expecting much out of this paint job. It is a perfect vehicle to practice with. I have no intention on ever painting any thing else, so I really don't wanna go out and buy a lot of stuff. But with so knowledgeable people helping me... who knows?
    I do have a project Mustang that will need painting one day.

  7. #7
    Join Date
    Nov 2006
    Posts
    2,135

    Default

    I donít think 2 water separators will help. The second one will just add resistance to air flow. The fact is that water separators only prevent liquid water from moving into the air lines. Liquid water is only half the problem. Water vapor in air that has been heated by an overtaxed compressor will pass through the separator unaffected. That water vapor persists until the air cools in the air line closer to the gun or just condenses as the air leaves the gun in the form of mist. The solution is to cool the air in a metal line that is sloped up away from the compressor and the sloping pipe lets the water flow back to the compressor tank where it needs to be removed by you opening the drain valve in the bottom of the tank. Another solution is demanding less air per hour letting the compressor run cooler. Using a small compressor at 100% of its capacity with no cool down cycle doesnít allow for this. Thatís one reason why spraying in multiple sessions would work better for you.

    Bob K

  8. #8
    Join Date
    Mar 2021
    Posts
    6

    Default

    ok.Got it,thanks. I feel like I am getting somewhere now. I bought the infamous HF purple gun, of course $9.95 Black Friday. It is rated that it needs 6CFM@40PSI
    Lke I said, I have available a couple more on borrow. Let me know which one do you think be better for this small tank even though I will be painting in sections, or if it will even matter sinse I will not be painting the entire truck at one time

    The other gun is a Campbell Hausfeld Gravity Feed 2.3 CFM@30PSI Air Compressor Recommendation of 13 Gallon or larger

    The last one is a siphon fed 1.5CFM@30PSI Central Pnuematic. That must be a HF brand, I think. Any way, which gun would be best in my situation
    The compressor is 21 Gallon 4.0 SCFM@90 PSI 1.5 Running HP 175PSI. On this comp, I think they have played with the numbers a little to make it seem better than it is.

    I looked up to find the diff between CFM and SCFM and still didnt understand Thanks everyone

  9. #9
    Join Date
    Mar 2021
    Posts
    6

    Default

    About the conventional Siphon feed. It only has a 1.8 tip. The paint will be single stage acrylic. The other two guns have 1.4

  10. #10
    Join Date
    Nov 2006
    Posts
    2,135

    Default

    I haven't used any of those guns so I canít give good advice about them but I like using a smaller tip to get better control of the paint going down. The larger tip may hose the paint fast and result in runs. Try just holding each one and try the trigger feel. Use the one that feels best in your hands or switch around and see which one works best for you. You may not even notice a difference. Put a half pint of thinner in each one and spray it on some cardboard to get the feel of how they spray. Use the one with the most even spray pattern.

    Bob K

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •