View Full Version : Cheapo gun sputtering
07-21-2006, 10:06 PM
I have a cheapo hvlp gun I am using to apply urethane primer to a fender. The gun keeps cutting out as I sweep across the fender. I read a few of the other posts and did find that the nozzle was loose (bubbles in the can) but while tightening rid me of the bubbles, i still have the sputtering. The gun has a can filter installed. My question is should this filter be removed when shooting primer? And also I had the issue earlier with the primer being almost dry when it hit the panel, could this be because of the air escaping into the can?:confused:
07-21-2006, 11:50 PM
The gun has a can filter installed. My question is should this filter be removed when shooting primer?
Absolutely! get that filter out of there , those things are more trouble than there worth with topcoats let alone primers , I don't know if it will solve your sputter , but it sure can't hurt ;)
07-22-2006, 01:03 AM
If that primer is going on dry then then either the primer is mixed too thick (thin it down a little) or you're holding the gun too far away. Or your air pressure is set too high. Or the tip is dirty. Or the air vent hole in the spray gun cup is clogged. If one or more of those don't clear up the problem then let us know.
07-22-2006, 07:04 AM
I am using a primer that calls for 4:1. What do I use to thin it out and how much?
07-22-2006, 09:06 AM
acrylic urethane reducer, not more than 10 % by volume.
07-22-2006, 09:35 AM
I use a turbine spray set up and I find that the hot air coming from the turbine (usually 90 degrees I think) heats the paint that's being sprayed and makes it dry a lot faster. Some high build 2k primers I've sprayed dried pretty much instantly on contact w/ the surface being sprayed. I started adding a lot more reducer and have been getting consistently better finishes.
07-22-2006, 06:09 PM
So instead of 4:1 should I go to 3:1 ? Too much or too little ...
07-22-2006, 06:15 PM
If you're using a urethane primer then the 4:1 ratio is 4 parts primer to one part hardener/catalyst. So just add a little urethane reducer to the primer and you should be fine.
07-22-2006, 09:51 PM
Thanks..I appreciate the help..I will try that tomorrow and report back.
07-23-2006, 07:34 PM
I pulled the filter and tried ...It worked much better but I still have an issue... The finished product looks almost striped. I overlapped each pass at 50% bt it seems as though the top and bottom of each pass was dry when it hit the car. The center is smooth bt top and bottom are not.. Too much air? Not enough material???
07-23-2006, 09:37 PM
Ya , i'd try cutting back the air , also maybe try turning your fan control down some to cut back the distortion in your spray pattern. Those cheap guns can be ok for primer, but you have to diddle with the settings a bit to get what you want.
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