Spray Gun Help
Thread Starter
Racer
Joined: Nov 2005
Posts: 340
Likes: 0
From: Dublin
Spray Gun Help
Was putting primer on last week with the gravity fed gun, but I seem to be having problems getting the correct fan width. I did manage to get most of the car primed and was delighted with the results, but I'm hopefully laying the paint down this weekend.
Then gun I have doesn't have an operating pressure stamped on it.
But from what i've read online the working pressure is between 10 and 20 psi.
I set the regulator to 20psi so i'm getting 10psi at the gun ( do not have and pressure indicator at the gun but the regulator drops to 10psi which I read is normal to lose 10psi in the line.
How much of a lower pressure should or could I go?
Then gun I have doesn't have an operating pressure stamped on it.
But from what i've read online the working pressure is between 10 and 20 psi.
I set the regulator to 20psi so i'm getting 10psi at the gun ( do not have and pressure indicator at the gun but the regulator drops to 10psi which I read is normal to lose 10psi in the line.
How much of a lower pressure should or could I go?
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
What size tip are you using? Is it compatible with your paint (per tech sheet) Mike is correct pressure is measured at the gun several things will effect it. Hose size, the length of the hose and the size of the hose couplers.
Safety Car
Joined: Jul 2005
Posts: 3,694
Likes: 833
From: WI
Actually, a lot of guns measure pressure at the CAP, not the inlet of the gun. In these cases, the instructions are easy to misinterpret. It's hard to know w/o looking at your gun, I would up the pressure and do a few test passes and see how it sprays. I'm guessing you might end up at 45-50 psi at the gauge on the gun. That's just a guess based on my use of some different guns. Be sure your paint is mixed properly as well. What kind of gun are you using?
Mark G
Mark G
Last edited by Mark G; Jun 30, 2012 at 12:02 AM.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Actually, a lot of guns measure pressure at the CAP, not the inlet of the gun. In these cases, the instructions are easy to misinterpret. It's hard to know w/o looking at your gun, I would up the pressure and do a few test passes and see how it sprays. I'm guessing you might end up at 45-50 psi at the gauge on the gun. That's just a guess based on my use of some different guns. Be sure your paint is mixed properly as well. What kind of gun are you using?
Mark G
Mark G
PSI is at the air cap on HVLP guns.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
Actually, a lot of guns measure pressure at the CAP, not the inlet of the gun. In these cases, the instructions are easy to misinterpret. It's hard to know w/o looking at your gun, I would up the pressure and do a few test passes and see how it sprays. I'm guessing you might end up at 45-50 psi at the gauge on the gun. That's just a guess based on my use of some different guns. Be sure your paint is mixed properly as well. What kind of gun are you using?
Mark G
Mark G
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
It sounds like you intend on using a primer gun to paint topcoat. 
But better than a brush I guess.
You'll want as wide of a fan spray as possible. I'd suggest starting at 40 psi gauge and adjust for paint viscosity. Too much pressure means you lose a few ounces bouncing off the panels as overspray. But too little gun pressure means the paint won't be atomized the way it's intended. I'd err on the former every time.
But hey, what do I know?
But better than a brush I guess.You'll want as wide of a fan spray as possible. I'd suggest starting at 40 psi gauge and adjust for paint viscosity. Too much pressure means you lose a few ounces bouncing off the panels as overspray. But too little gun pressure means the paint won't be atomized the way it's intended. I'd err on the former every time.
But hey, what do I know?
Thread Starter
Racer
Joined: Nov 2005
Posts: 340
Likes: 0
From: Dublin
Hey
Thanks for all of the advice
It turned out that the problem was the gun itself.
The fan spray adjuster had no effect on the width of the spray. Was set to very narrow
I used the pot spray gun I had; much better results. Although I do have a couple of questions that i'll start in post.
thanks
Thanks for all of the advice
It turned out that the problem was the gun itself.
The fan spray adjuster had no effect on the width of the spray. Was set to very narrow
I used the pot spray gun I had; much better results. Although I do have a couple of questions that i'll start in post.
thanks