Pulled out my old Accuspray today to shoot some paint at some cabinets. I had not used it in a few years . Last time I used it was to spray some three part marine linear polyurethane (Awlgrip – nasty stuff). Gun was cleaned well and and it had been stored back in its original carton.
To spray waterborne enamel, the local Accuspray dealer suggested a #10 air cap and a .51 needle / nozzle. I bought one, changed it according to the Accuspray manual. However, when I turned on my turbine, I had a fairly strong stream of air around the tip. Problem is that this occured before I squeezed the trigger. I did not get any paint, just the stream of air. When I did pull the trigger, I was able to get paint, but it wasn’t atomized the way you’d like – it was a bit chunky. Could tell that the one quart pot wasn’t being pressurized the way it should be.
What might be my problem? I had changed out the packing before I used it a couple of years ago. Could that be the culprit? What else might I try. When this gun works well, I don’t recall getting much, if any air at the tip before I pulled the trigger. This is definitely different. Would appreciate any thoughts.
Regards,
Bob
Replies
I'd empty the gun then set up to spray with nothing in the cup. If you still get air at the nozzle, then the air cap might not be matched to the needle. If it never leaked air before like this, I'd thin the paint and try spraying again. It sounds like your material is too thick to atomize properly.
Robbie,
If you had your one-quart pot screwed on tightly while it was stored, you could have compressed the gasket to the point where it's lost its ability to seal properly.
-Jazzdogg-
Whether you think you can, or you think you can't, you're right.
Thank you for the responses.
Jazzdog: With respect to the jar top, I changed the gasket before spraying. At any rate, the premature air release is actually from the aircap itself - almost as if the trigger is being pulled but no fluid is released. It is a good thought, though. Thanks.
Jackplane: I will give your suggestion a shot. The aircap is a #10 and comes with the .51 needle / tip as a kit and so hopefully they were adequately matched at the factory. You may also be right about the material being too thick. I did thin it 10% with water and added another 10% Floetrol. Until I get full pressure to the pot, I cannot really tell. Right now the pressure is escaping the aircap before my pot is fully pressurized. I am still able to spray, but it is not as fine an atomized spray as I'd like it to be.
I called Accuspray and they thought it could be that the "seal and pappet valve??" might be the culprit and suggested I take the entire gun apart and replace the valve and seal.
Yikes! I guess no guts, no glory. Never expected to be taking this thing apart.
Try cleaning and lubing it first. Then take it in if you need to.
Darkworksite4:
El americano pasado hacia fuera ase la bandera
The technical guy at Accuspray was pretty good. He gave me some thoughts and on Saturday morning, I did something I never wanted to do... disassemble the spray gun and take it apart. As it turns out, it was the pappet valve that was stuck. This is the little plastic plunger that the trigger depresses after it depresses the needle plunger. Essentially, it was stuck in the "on" position and so air was being sent to the tip constantly, making it difficult for the cup to pressure up.
Was able to take it apart and reassemble it in 20 minutes and the repair was effective.
cool I really like those accuspray guys.
Darkworksite4:
El americano pasado hacia fuera ase la bandera
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