Orange Peel Factors

[theodoropoulos]

i try to spray acrylic bronze with a 1.4 nozzle but there is always an "orange peel" which i cannot get rid off.

My question is what is the combination of

a)air pressure

b)viscocity of liquid/thinner percent

c)nozzle

d)liquid fluid

e) distance from theme

in order to achieve a perfect paint/finish..

most of them i am concerning about how an acrylic liquid viscocity is connected with nozzle....i mean if my nozzle is 1.4 and see orange peel,

should i try with 1.8 or 1.0???

Edited August 9, 2010 by theodoropoulos

[ihocky2]

Generally the first things to try with orange peal are reducing air pressure and/or increasing gun to work distance. A larger tip will only get you more fluid, good for dry spray issues, but orange peal is typically an air pressure issue. Those are the first to things to try, after that you can move onto other factors.

The smaller tip provides better atomization, so you don't need as much air pressure to break up the fluid. When setting up for new products I usually start at the bottom of the recommended air pressure and increase until I get good atomization and stop there. I used to start at the high end, but learned quickly it took too long to get a good setup until I got rid of orange peal.

[theodoropoulos]

Generally the first things to try with orange peal are reducing air pressure and/or increasing gun to work distance. A larger tip will only get you more fluid, good for dry spray issues, but orange peal is typically an air pressure issue. Those are the first to things to try, after that you can move onto other factors.

The smaller tip provides better atomization, so you don't need as much air pressure to break up the fluid. When setting up for new products I usually start at the bottom of the recommended air pressure and increase until I get good atomization and stop there. I used to start at the high end, but learned quickly it took too long to get a good setup until I got rid of orange peal.

it would help me a lot to give typical min prices for poly and water based finish...Stew mac refers 30 and 40 psi...

but in my project i spray with HVLP water based Bronze type B and it needs 70-90 psi.....I think its crazy ....

What's your opinion?

[ihocky2]

With an HVLP gun you are not as worried about the air pressure going into the gun as much as you are the pressure at the air cap. Without getting a gauge to test pressure at the air cap it is all guessing. But for my mini HVLP gun I have the regulator mounted directly before the quick connect to the gun. When I have the trigger pulled the pressure drops from the 80PSI coming out of the tank to about 5 to 10 PSI running through the gun. The pressure you want to watch is the pressure with the gun operating. That is your working pressure and what breaks up the paint. HVLP moves a TON of air, so your pressures will be really low with the trigger pulled and really high with the trigger closed. If my tank pressure is below 70 psi I get crap atomization because I don't have enough air coming out at the air cap to break up the fluid.

I hope this helps.

[theodoropoulos]

With an HVLP gun you are not as worried about the air pressure going into the gun as much as you are the pressure at the air cap. Without getting a gauge to test pressure at the air cap it is all guessing. But for my mini HVLP gun I have the regulator mounted directly before the quick connect to the gun. When I have the trigger pulled the pressure drops from the 80PSI coming out of the tank to about 5 to 10 PSI running through the gun. The pressure you want to watch is the pressure with the gun operating. That is your working pressure and what breaks up the paint. HVLP moves a TON of air, so your pressures will be really low with the trigger pulled and really high with the trigger closed. If my tank pressure is below 70 psi I get crap atomization because I don't have enough air coming out at the air cap to break up the fluid.

I hope this helps.

sure!!!thanx!