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Old 08-06-2015, 08:48 PM
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patriot patriot is offline
Join Date: Apr 2015
Location: Land of Enchantment
Posts: 107
Default Dumb, dumb, dumb, ...

I'm going to expose my stupidity, but hope this will help someone when they have a similar problem.

It's about my trusty gravity-feed spray gun. It just began pulsating - spray, no spray, spray no-spray etc etc etc .... This was driving me nuts. It was PERFECTLY clean. I could see through every orfice in the air nozzle, the fluid nozzle and the needle assembly was spotless. I could also see through the opening that the fluid passes through. It WAS CLEAN!! So what the heck was the problem?

The air pressure was set correctly. So what was the problem???

I have been using it to spray on water-based stain and shellac of the 1-lb variety. Both have the consistency of water. Nothing thick like latex paint. It worked fine about a month or so ago, but not now.

I used acetone to clean it after spraying stain and alcohol after spraying shellac. The acetone removed all of the brown residue of the stain so I know that worked.

The filter was a bit brown but I would always run either water or alcohol through it when done. But this made no difference at all. It continued to sputter.

Then today a little voice said, "Yo bozo, remove the filter and try it." I did and the pulsating was gone. I grabbed the filter and tried to blow through it and I could not. "But, but ..", I said, "It's nearly clear!" Yeah, well, in this case that meant NADA NOTHING. The filter was plugged even though it appeared to be clear.

So the moral of this story is just because the filter 'looks' clean or clear does not mean that it really is. It could be that the shellac caused this, but because I always ran alcohol through it after using it, I am not sure that shellac was the culprit in this case. Could be that filters just get plugged up and you have to replace them every once in a while. I am no expert so I am not certain of this.

I hope this helps someone.

Phillip Anthony
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