Register now to get rid of these ads!

Spray gun problems

Discussion in 'The Hokey Ass Message Board' started by fred56, Sep 10, 2009.

  1. fred56
    Joined: Jul 27, 2005
    Posts: 55

    fred56
    Member

    I went to spray on Black lacquer paint with a Sharpe 998 Siphon feed HVLP gun(I know buy a regular HVLP) and at first it sprayed on nice and the more I painted the paint started to dry gray looking and no matter what I adjusted the results were the same.
    Does anyone have an idea what I am doing wrong?
    Jerry
     
  2. lippy
    Joined: Sep 27, 2006
    Posts: 5,592

    lippy
    Member
    from Ks

    Maybe humidity? Retarder or slower reducer. I can't see how the gun could have any effect on the color change.Make sure your not getting oil or moisture out of the line also. Lippy
     
  3. Rick Sis
    Joined: Nov 2, 2007
    Posts: 710

    Rick Sis
    Member
    from Tulsa OK

    Been getting some rain in Ohio? As Lippy said, the description does sound like it's blushing from humidity. Always best to watch the weather and wait for dry conditions when spraying lacquer. Your Sharpe gun should work fine.
     
  4. skullhat
    Joined: May 30, 2009
    Posts: 892

    skullhat
    Member

    get some slower thinner and retarder in there and try again.

    if you air cap and or fluid nozzle are clogged, the dry overspray produced can give a whiteish or gray appearance

    with lacquer you need`to clean your nozzle and cap more frequently

    skull
     

  5. fred56
    Joined: Jul 27, 2005
    Posts: 55

    fred56
    Member

    Thanks for the fast answers, due to the current weather it sounds like you have a handle on my problem.
    Thanks - Jerry
    P.S. I just checked the gun and found that the air breather hose to the cup was blocked. That couls also have caused the dry overspray.
    Thanks again.
     
  6. skullhat
    Joined: May 30, 2009
    Posts: 892

    skullhat
    Member



    that will do it, they make your gun run "lean"


    its been awhile since i used a gun with a vent in the cup, but i recall in the day always looking for something to stick in the small hole to clear the vent
    or you could stick your finger over the air cap, charge the cup,and make a pressure pot out of it, lol

    now days we use those 3m pps cups, no vent, and they will even paint upside down, and paint flow is conssitant, and they wont leak.

    good luck with that lacquer job

    skull
     
  7. SlowandLow63
    Joined: Sep 18, 2004
    Posts: 5,953

    SlowandLow63
    Member
    from Central NJ

    A piece of welding wire will do the trick, or a paper-clip, torch tip cleaner, etc.

    I've always thought about converting to the PPS system but never have. Its awesome that they spray upside down. I wonder if they can spray in space???????????? :D :D
     
  8. skullhat
    Joined: May 30, 2009
    Posts: 892

    skullhat
    Member

    yes, that part got figured out, lol. its a rule of painting that when in the booth, none of those items can be found within a 100 yard radius.:)


    skull
     
  9. SlowandLow63
    Joined: Sep 18, 2004
    Posts: 5,953

    SlowandLow63
    Member
    from Central NJ

    You don't weld or cut with a torch in your paint booth?? :D
     
  10. skullhat
    Joined: May 30, 2009
    Posts: 892

    skullhat
    Member



    .............sometimes, you know, when you see that last little spot , just as you're ready to paint:eek:
     
  11. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey,

    It sounds like the blocked vent tube/hose is/was your problem.

    What is your lacquer thinned at? Most lacquers are thinned at 150%-175%. If you're tryin to shoot your top coat on thick, that could spell trouble up the road, to say nothing of poor gun performance!

    NEVER attempt to clear the fluid cap or fluid needle of a spray gun by placing one of your fingers over the air ports! Even at 65# at the gun, pressures at this level can force paint & thinner into your skin, and into your blood stream causing blood posioning. I once had an old painter friend who we buried with nine fingers, he lost one doing just what I advise against!

    Swankey Devils C.C.
    '' A legend in his own basement"
     
  12. jimi'shemi291
    Joined: Jan 21, 2009
    Posts: 9,499

    jimi'shemi291
    Member

    PimpinPaint: Man, I am glad you mentioned that SAFETY tip!!! It would be REALLY easy for any guy to fall into that situation, if you got frustrated enough!!! THANKS
     
  13. fred56
    Joined: Jul 27, 2005
    Posts: 55

    fred56
    Member

    Pimpin paint - The thinner was reduced 125% as per their instructions. Do you think I should thin it out further?
    Thanks - Jerry
     
  14. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey Jerry,

    I'd suggest this: Empty and clean the spray gun completely! Pour some fresh thinner into the gun and check the spray pattern on some 36" paper taped to the shop wall. Be sure to adjust the gun for a full, clear pattern, no fuzzy margins, no funny areas in the middle of the pattern. If what you find is that you can't get this from the gun, you've a gun problem, not a paint problem. Repair/replace the gun and try a pattern, again with the 36" paper, this time with correctly thinned paint material. @ 150% with a slow thinner and correct pressure at the gun, you should have no trouble laying down a wet spray pattern. Be sure you're giving it a full 50% overlap on your spray pass. On some of the cheap-ass HVLP guns you have to wait for proper atomization at the spray tip. If you're going too fast for the gun, you'll produce a dry, uneven spray pattern.

    Swankey Devils C.C.
    "I liked the old millennium better"
     
  15. fred56
    Joined: Jul 27, 2005
    Posts: 55

    fred56
    Member

    Thanks for all the information it really helped. I reshot all the bad areas and it came out perfect.
    Jerry
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.