Hey guys,
My friend and I got the purple harbor freight HVLP Gravity feed spray gun. I was going to roll-on rust-oleum marine paint, but I've now decided to spray it. I believe that HVLP guns are supposed to be regulated at the gun at 8-16 psi, correct? The reason why I am asking is because if I do so, it sprays like crap; very spattery. I thinned the paint according to the can (10% xylene, for spray applications). If I turn up the gun to 30-35 psi, it sprays very nicely. Why is the gun spraying like this at lower psi? Any help/set-up tips with the Harbor Freight HVLP??

 

16 psi is to low, just turn it up as you were doing. Some techniques, different styles are up to 50-60 psi. Different materials, applications, environments may all have different pressures, so one standard pressure for everything isn't realistic. Test little spray outs to find out what suites your needs.

 

i found a couple of good tutorials online...showing how to spray a test area
http://www.hotrodders.com/kb/b....html

 

Roll on paint is very thick even when reduced.An automotive spray gun is used for very thin paint.The viscosity of the paint or thinness depends on what size tip you need to use.Something that thick in auto terms you could use a 1.8 fluid tip anything smaller and you would have the problems youre having.

 

If you have it at 8-10psi at the regulator, that's like 1-2psi at the cap.

You need to have 8-10psi at the CAP. Which means like 30-45psi at the regulator.

 

lol wow....thanks guys!

 

yea like they said. you set the regulator at 40 psi when the trigger is pulled. its around 43 when the trigger is idle.

 

you need 30 psi @ the gun with with the trigger pulled and real paint.

once you have those two things go to http://www.autobody101.com and read up on how to do an atomization test.

that gun is harbor freight p/n 90977 requires 5.9 cfm @ 29 psi.

the gun is spattering because there's not enough air to atomize the paint.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eda6 &raquo;</TD></TR><TR><TD CLASS="quote">you need 30 psi @ the gun with with the trigger pulled and real paint.

once you have those two things go to http://www.autobody101.com and read up on how to do an atomization test.

that gun is harbor freight p/n 90977 requires 5.9 cfm @ 29 psi.

the gun is spattering because there's not enough air to atomize the paint.

</TD></TR></TABLE>

Good info man...

 

do understand I know you can turn the pressure up and it will work but hvlp are meant to keep vocs down and put more material on the vehicle at A LOWER PRESSURE. He could have bought a standard cheap gun and it would have served his purpose