TheCoatingStore.com

Results 1 to 8 of 8

Thread: clogging spray gun tip

  1. #1
    Join Date
    May 2007
    Posts
    11

    Default clogging spray gun tip

    I have been cleaning this gun after every spray, including pulling the needle, brushing etc. The paint is always strained going into the cup.
    I have had this problem with the gun strainer both installed and uninstalled.

    The gun works for about 2 minutes, then you get paint fade, you can't get media running through it unless you tighten your pattern All the Way In full tight.
    If you fan it out again, barely any material. The flow adjustment doesn't help. This is happening with primer, base and clear.

    I noticed that the tip appears to be getting clogged.

    Could this be a problem with air pressure? I may be setting the pressure wrong. The gun uses 6-9 at the cap and 30-43 at the gun. But, I set the gun at 43 lbs without the trigger pulled!
    If memory serves, I think the pressure drops to around 20 psi with the trigger pulled.

    Thanks
    Last edited by graphixv; 05-26-2013 at 07:19 PM.

  2. #2
    Join Date
    Nov 2006
    Posts
    2,046

    Default

    First, set the pressure with the trigger pulled. Donít worry about the cap pressure. That is stated for legal reasons but there is no way to measure it without a dedicated tool for doing just that. When you set the inlet pressure as the gun manufacturer states then you will get the proper cap pressure.

    Your paint flow problem sounds like the vent for the cup is plugged. As long as it comes out good at the beginning then you can rule out a plugged tip. As you remove fluid from the cup a vacuum starts to form in the cup preventing further flow of paint. If the cup vent is open then the vacuum can not form and the paint will flow until the cup is empty. You didnít say what gun you have so I canít tell you where the cup vent is located, but when you find it you should be able to check it by pushing the tip of a tooth pick through the vent opening. If you have a DeVilbiss gun there is a cap on top of the cup cover vent. Both the vent hole in the white cup cover and the vent hole in the black cap need to be checked.

    Bob K

  3. #3
    Join Date
    May 2011
    Posts
    21

    Default Vent ...........

    If the vent is plugged it will run out of air ,sounds like vent to me .

  4. #4
    Join Date
    May 2007
    Posts
    11

    Default

    To be honest, I didn't realize spray cups even had vents! This is my first paint job.

    What is weird is I can see material (trash) on the sides of the needle, clean it off and then the paint starts flowing again. At least, for another minute or two. Can it be a vent if clearing the needle causes paint to resume flowing? The tip is the 1.4.

    Up to this point, I've been painting doors and trim pieces entirely off the car. But I'd rather fix some of my issues before I drive what's left of the car body in.

    I'll check the cup again in the morning. The manual shows an Air Release Plug on the top of the cup (perhaps this is the vent) but doesn't mention anything about it in the manual at all. I have to respray some primer that had to be sanded out when I cleaned off the gun needle and the thing started hosing it out!
    Yeah, I ran primer. Primer!
    Last edited by graphixv; 05-27-2013 at 12:11 AM. Reason: No links please

  5. #5
    Join Date
    Nov 2006
    Posts
    2,046

    Default

    Air probably got into the cup while you were cleaning the tip and broke the vacuum. If you want to test it, fill the cup with water, put the cover on the cup and start spraying into the air. If the vent hole is plugged the spray will soon slow down or stop. To prove that it is really plugged lift the cover off and with the cover gone it should spray well until the cup is empty. Take the gun apart and dry it out well incase it isnít designed to be used with water.

    Bob K

  6. #6
    Join Date
    May 2007
    Posts
    11

    Default

    I went ahead and made sure the vent was clear, it did appear to have some blockage before I cleaned it out.
    However, whenever I have been cleaning this gun I have been shooting thinner through it and have had no problems shooting all the thinner in the cup.

    I went ahead and did my primer touch up after making sure the vent was clear but had the same issues.

    I even upped the pressure at the gun.

    I'm having to wipe off the tip off about every 60 seconds to keep it clear of trash and to keep material moving. I'm planning to try a little reducer in my base and see if I have the same problems then. So much for technique. Kind of hard to do that fighting your gun the whole time.........

    N

  7. #7
    Join Date
    Nov 2005
    Posts
    41,167

    Default

    Quote Originally Posted by graphixv View Post
    I went ahead and made sure the vent was clear, it did appear to have some blockage before I cleaned it out.
    However, whenever I have been cleaning this gun I have been shooting thinner through it and have had no problems shooting all the thinner in the cup.

    I went ahead and did my primer touch up after making sure the vent was clear but had the same issues.

    I even upped the pressure at the gun.

    I'm having to wipe off the tip off about every 60 seconds to keep it clear of trash and to keep material moving. I'm planning to try a little reducer in my base and see if I have the same problems then. So much for technique. Kind of hard to do that fighting your gun the whole time.........

    N
    Remove the air cap and fluid tip and clean both well then closely inspect the fluid tip to make sure it doesn't have any nicks or scratches near the tip. Are we talking about a "name brand" spray gun or is it a no-name type? Also make sure that the holes in the air cap are clear.

  8. #8
    Join Date
    Jul 2011
    Location
    South Africa, Pretoria
    Posts
    460

    Default

    What size needle are you using and how is the viscosity of the paint?
    And as Len said, strip the gun and clean it real good.

Tags for this Thread

Posting Permissions

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