stopping orange peel

[mongocanfly]

I had some bad orange peel on some of my parts I painted the other day...during the same paint session some of the other parts came out flawless and slick as glass...
so I know some of its operator error
my paint pds says to set the hvlp gun inlet pressure at 8-10psi..im using a eastwood concours pro hvlp gun...from past experience turning up the pressure helps eliminate the orange...the last pieces I sprayed I turned the reg up to 12psi..and it seemed to help a lot..just wondering , how high can I go and will it help by adding more psi's...im using a 1.3 tip..
I just found a video on the gun where he sets the gun at 30psi...
https://www.youtube.com/watch?v=SQe3D4KuSBQ
so how much is to much?
the paperwork on the big gun doesnt say anything about setting inlet psi's

the instructions for the small detail gun I have says, inlet at 22psi..its also a eastwood concours...used it for the 1st time the other day, and I ran it at 22psi and a 1.0 tip ,and it painted good

[dsraven]

check the gun specs, most say the pressures you listed but that is nozzle pressure, not in;let line pressure. usually I set mine at 28-32 psi line pressure.
if you have a piece of cardboard you can hang on the wall or better yet something hard that won't absorb the paint like cardboard will, fill the gun then shoot a quick pattern check to ensure you are getting a nice fan. 8 to 10 inches away. if good then turn the nozzle sideways and shoot another one horizontal, this checks the amount of paint coming out. if it runs then turn the needle plunger screw in a bit and try again.
usually I set my needle screw almost all the way out to start, then adjust the air screw and do a few patterns, adjust stuff till you get it the way you like, then shoot the paint. another thing that can happen is the nozzle gets a paint icicle hanging off of it, or the vent in the cup gets partially plugged so sometimes it seems like you get a good texture and then suddenly it is orange peel, thats when the vent plugs and you get a dry fan because there is not enough paint coming out for the amount of air in the fan.
hope that helps.
my gun is a devilbis starting line, came as a set with a primer gun as well. seems to do the job pretty good. I did fight the same issue as you but found out the pressure set out by the paint supplier is nozzle pressure not line pressure. some of the primers are pretty thick so that doesn't help. I was having some isues with the high build epoxy but added some reducer and it flowed out better. cranked the line pressure as well. thats when I found out the pressure recommended was the nozzle pressure. dunno how youre supposed to measure that anyway.
post up a few pics, would like to see how it turns out.
if orange peeling go over it with more paint after setting the gun a bit different, after checking the vent and nozzle of course.

[mongocanfly]

I do the spray pattern test each time...it always looks good on paper...and I use dekups system on the big gun..so venting is no issue..i keep thinking its a pressure issue
and I clean the nozzle between each coat to prevent buildup

[notsolo]

Good video about the pressure settings!.....Also could be the speed your moving the gun and keeping the gun angle at 90 degree's. I have sprayed some awesome orange peel.

[mongocanfly]

I tried to be extra careful to keep the gun at 90deg to the surface..and I was moving sorta fast..

[mongocanfly]

Ok..finally got a reply back from Eastwood..they are limited staff so it took awhile..their tech says I need 28-30psi at the inlet ...so this may be my issue...
This was his reply ..I dont know why they couldnt have put this in the instruction manual...

First of all the PSI give to you about the paint is measured at the tip. If you have a regulator at the gun set it around 28 to 30 psi when the trigger is pulled. Make sure the air valve on the bottom of the gun is wide open, your using a regulator. Orange peel is usually caused because the paint is drying to fast and its not flowing out. If your pressure is to low also you may not getting enough paint for it to flow out also. May also need to increase the amount of material coming out of the gun. A little more paint might also help you stop the orange peel.

[notsolo]

You have probably seen this, or some like it. it helped me get better results. Wish we had resources like this 30 yrs ago..... https://www.youtube.com/watch?v=AYB4Yxeq_M8

[nsb29]

Adjusting you’re gun it’s like adjusting the carburetor you have to get the right air flow versus material but your pressure was definitely too low spi Has some information on their site a on adjusting your gun

[mongocanfly]

Yeah , I realize that now...what's odd is some of the painted parts are slick as glass..but I'm definitely cranking up the psi's

[MP&C]

http://www.spiuserforum.com/index.ph...84/#post-54102

[lupo]

Originally Posted by notsolo

Good video about the pressure settings!.....Also could be the speed your moving the gun and keeping the gun angle at 90 degree's. I have sprayed some awesome orange peel.

That was a great video. Troubleshooting charts say the gun pressures to high pressures or is to low. Big help. I've made a lot of orange peels and I always suspected the gun pressure was to high and too close to the surface. Late in life I learned to spray a scrap piece of metal not paper to see where I was at.

[mongocanfly]

Thanks Robert..so much to learn...

[Gregski]

Originally Posted by notsolo

You have probably seen this, or some like it. it helped me get better results. Wish we had resources like this 30 yrs ago..... https://www.youtube.com/watch?v=AYB4Yxeq_M8

I am a robot, I am a robot...

[mongocanfly]

Haha..last night while I was fixing my orange peels...I kept repeating that...ima robot,ima robot,ima robot...in my robot voice

[mongocanfly]

well I turned my gun pressure up to 29psi..what a difference it made...I had to repaint all my previously painted parts
when I started trying to wetsand the painted parts ,the orange peel really started looking bad...the more I sanded the worse it looked....1500g was a waste of time...600g would wear you out just on one panel..so I dropped down to 400g...and it still wasnt easy ..but I got it all out...
that led to repaint because I started getting into primer..
the paint went on almost smooth as glass..a huge improvement from before
I havnt wet sanded anything yet but it looks so much better than it did...if it wasn't for the nibs, id almost let it go like it is..

[dsraven]

I've been shooting primer at 28 to 32 psi line pressure. I have a gauge on the gun inlet and hold the trigger while adjusting the line pressure. When good I remove the gauge. Also important to use a 3/8" or larger air hose and run compressor at around 120 psi for good air flow. Some guys also swear by high flow quick connects. It makes impact guns etc work properly. Paint guns too.years ago a shop i worked at had run 3/4 inch black pipe air line.
We found the 1" impact guns ran slow. They upgraded to 1 inch and the big guns worked like they were supposed to.not enough air flow available to get the big truck lug nuts off before.
Glad you got it figured.

[theastronaut]

Just now seeing this, sounds like you're on the right track with pressure adjustments.

I have a 1.3 reduced pressure gun (between a conventional and HVLP) and the 1.3 tip is kinda slow on getting enough material out of the gun and onto the panel even with the fluid control all the way open. You need enough material on the panel so the atomized paint can flow back together and flow out smoothly, so once you have the pressure like it needs to be (sounds like you're already there) try gradually opening up the fluid control if you have it closed off partially. That'll get more material on the panel faster so it flows out easier. It also means runs happen faster

Using a slower reducer and activator gives the paint more time to flow out before it sets, which can also help reduce orange peel. This is important on higher solids paints.

[mongocanfly]

Thanks John...I'm running the fluid almost wide open with a 1.3 tip now....when I put the gun together after cleaning, I start running the needle in with the handle pulled all the way back..when I feel resistance I turn the knob a half round more..I did one session at 29psi...it was good..the next I turned it up to 30.5psi...seemed to lay down a little better..but during wet sanding I cant really tell any difference it all seems the same....
I'm trying to clean up with 2000g but I think I'm gonna have to go 1500g in some areas...
I'm scared to wet sand to much....

[dsraven]

one thing I do when painting is over shoot onto the masking in a couple spots, full overshoot like you are actually painting that masked off spot. that way you get a good idea of how the actual paint on the panels is cured without touching that part, just touch the masked off area. with clear I touch it and pull my finger away. if there are no stringy things coming off when I pull my finger away then it is ready for the next coat.
an extra coat of clear on top gives just a bit more thickness to work with. wet sand the orange peel till smooth and then give it another shot of clear if you are worried about getting thin. that is if the gun is set up now so you get a smooth finish. then color sand it and it's all good.
post up some pics of how it worked out for you

[mongocanfly]

Raven..I'm using single stage paint...

[dsraven]

Ok, well same goes. Shoot a masked off area so you have a test area.

[mongocanfly]

I do carry the spray on past the tape...and I have a paper sheet hanging on the wall that I test spray on..thanks for the tips...