Wagner HVLP Conversion Gun

[Jerry Bittner]

Trying to put a second coat on a dresser I've just finished and the Wagner HVLP conversion gun NVC Model won't spray. I'm using a water based polyurethane that I've used before without trouble.

I've read the troubles shooting section of the manual and replaced the valve but still no luck. Noticed that when I pull the triger without the can secured but the pickup nozzle can be seen, the fluid in the can bubbles. Which I thought strange since this is the pick up tube for the spray material.

I've disassembled it about five times and looked for blockages but can't see anything out of the ordinary. Thought I've doe a decent job cleaning it after every use, but apparently something is amiss. The Gleem company where I purchased it is down for the day so unless someone can help me, I guess I'm done finishing for the day.

In a follow up post I mentioned tht I found the suction tube was clogged with a small spring. Checked with Gleem and they said there is no spring or valve in the suction tube -- just a tube. And the spring I found is definitely not a part of the gun.

Interestingly enough, he mentioned that they have other reports of foreign objects being in paint that have caused similar clogs. First time report of a spring however. Guess the lesson here is that it would pay to strain your paint or finish thorugh some cheescloth before pouring it in the cup. In other words don't assume the manufacturer's quality control is infallible.

Thanks to all who posted trying to "unclog a clog."

[Jim Becker]

When you cleaned it, did you put the valve on the pressurization connection (between the gun and the cup mount) back on backwards? It's "one way"...

[Mike Vermeil]

I've been using this gun for about 6 months now with no trouble on all types of paints and polyurethanes. When you say the gun won't spray, what exactly do you mean? Is air coming out w/ no liquid, or nothing at all?

[Jerry Bittner]

Thanks Jim for the response. In fact I put a new valve which only goes one way and made sure the arrow points up toward the spray head.

I do get air flow out of the nozzle and have been able to coax a little spray out of it but nothing like it should be.

Disassembled the pickup tube and even tried to run some mineral spirits through it but to not avail. Its only been used for water based finishes.

[Mike Vermeil]

Jerry,

1) Did you check that the valve is working correctly?

2) I'd double check that you have correct pressure getting to the gun, and have the regulator at the gun set properly also. I'm no expert, but I run at least 35 pounds to the gun, and 10-15 at the tip.

3) How many turns is the flow adjustment backed off (the big knob at the back of the gun)? For water based poly I usually back it off 1.25 to 2 turns. If it's not backed off enough, you won't get enough liquid flowing.

4) If none of the above helps, I'd check for passages within the gun being plugged. Water based materials dry very fast, and can be difficult to clean out of the gun if any gets up into the air passages. I accidentally installed the check valve backwards one time, and water based paint flooded all around the nozzle, etc, and cleaning it all out was a pain.

Good luck.

[Phil Phelps]

I'm not familiar with that type of gun, but you have something clogged somewhere. Use pipe cleaners and lacquer thinner to clean the tubes and passages. Hold the nozzel up to the light and clean with a needle. Turn up the pressure to 70. Take a sledge hammer and..... well, try the other stuff first.

[Jim Becker]

Thanks Jim for the response. In fact I put a new valve which only goes one way and made sure the arrow points up toward the spray head.

Umm...I believe that may be the wrong direction. The valve is in the line that supplies pressure to the cup to push the finish up the metal pickup from the bottom of the cup. The one-way valve is to keep finish from backing up into the air supply as you open and close the trigger and have pressure variations. Try it the other way around...

Although I don't disagree with Mike that waterbourne finishes dry quickly...I've left my gun sit for a day and a half without any issues since it's "sealed" when the trigger is not pulled.

[Cecil Arnold]

I think Jim's right, you can check by taking the valve off and blowing through it to see if the air is flowing into the cup.

[Jerry Bittner]

In the department of "can't figure", I disassembled the suction tube and found it was clogged. Along with a lot of gook, out came a spring about 1/8 inch in diameter and about 2 inches long. The question I posed to the Gleem people, (haven't got an answer yet) does the spring belong in the suction tube or is something that got sucked up from the other department of "how the heck did that get into there."

Any way the gun seems to be working well again. But I can't help wonder about the spring.

[Jim Becker]

Hmmm...spring. Not the one that controls the projector needle, I hope...

[Andrew Ault]

Is the spring intended to keep the tube from collapsing?