Could use some help with settings

mitch_04

Learnin'
Hi everyone,
I have been spraying quite a bit more lately and I have developed some questions (hence all the threads). I've gone through the gun setting according to Barry and searched to see what everyone is setting their guns to, but I would like to know some other things if anyone could help.


1. What does air pressure do? I've noticed when it's too low it sprays like you are texturing drywall, so I'm assuming it atomizes, but what happens and how can you tell if it's too high?

2. The fluid control obviously controls the amount of fluid, and therefore the orange peel. Once again, it seems that when it's too low it's a texture gun but more of a dry spray than clumps. What I'm having trouble with is how do you know when to stop adding fluid? If I have some orange peel, have I gone too far with the fluid? Or am I spraying too slow? Or a combination of the two...

3. Is it possible to spray epoxy like glass, or is it just naturally a little peely? I know it doesn't have to be, but I spray it often so it's something easy for me to practice with and if I mess up it gets sanded anyways.

I have had the oddest issue on a hood, one half came out very well, then the other side was too dry. Sprayed from one edge to the other, not sure what happened... maybe I held my gun farther away when I switched sides at the middle. I also seem to have the smoothest paint on the edges, great mirror but the rest of the panel isn't as clear .

I know I'm long winded, but it's just my nature to be thorough.
 
Forgot one more...

4. What paints are equivalent for settings? Would the gun be set nearly the same for epoxy sealer and base since they are thinner, and single stage set similar to clear coat?

I swear I can spray clear better than single stage, just not sure why .
 
Different air caps and needles will need different settings. It's always a dance.

If you turn your air cap so it sprays horizontally, then go through Barry's procedure, you'll see when you have hit the optimal set up. The pattern will be even all the away across. Too much fluid and you'll get runs.
Each gun has a sweet spot in its pattern. An easy way to find it is to set your pressure and pull the trigger with nothing in the cup. Hold your hand in front of the air flow and move the gun toward your hand. When you hear the sound change, it will get louder and deeper, you've found the optimal spot for atomization and spraying distance. There is a video from SATA on Collisionhub.com that explains it.
 
If you turn your air cap so it sprays horizontally, then go through Barry's procedure, you'll see when you have hit the optimal set up. The pattern will be even all the away across. Too much fluid and you'll get runs.

I was watching a YouTube video where a painter said when you do this, hold the trigger for 3 seconds. If you get runs, you have the fluid set too high.

Would you (or others) agree with this? Seems like a long pull to me, but if I knew what I was doing I wouldn't be asking these questions!
 
temp/humidity/barometric pressure all effect the gun so it changes often. 1/2 turn of fluid or 5 lbs of air etc . keep a door skin or something handy when you paint. set your gun and test . then adjust. better than trying to set it while painting the car.
 
I've been using my '85 C10 project as a test panel lately, since it'll all get sandblasted when I get to the bodywork stage anyways! I am going to keep an eye out for a big hood to practice on as well, something I can spray a couple lines on and still have some room to adjust and spray a couple more.
 
I was watching a YouTube video where a painter said when you do this, hold the trigger for 3 seconds. If you get runs, you have the fluid set too high.

Would you (or others) agree with this? Seems like a long pull to me, but if I knew what I was doing I wouldn't be asking these questions!

I agree with AAE that one second is plenty long enough. You will find that your spraying speed (distance you cover in one second moving across the panel) will affect this setting as well. For example: pretend you are spraying the top of your desk and moving from left to right, how many inches did you move your hand in one second. This will affect your final fluid adjustment. Learn to be consistent in your spraying speed so that your gun will repeatedly perform well with your settings.
 
Thanks everyone. I did some more spraying today with my LPH80 and did a ton of spray tests on the wall turning down fluid and pattern 1/2 turn each time. I had pretty good luck spraying, but I still just don't feel like I'm "fine tuning" it too much. I had probably 1.5 turns worth of sprays that looked the same to me, on both fluid and fan. I was using a tape measure to keep distance the same throughout. I also was painting something small, so it was hard to tell if any adjustments were affecting it. Either way, it turned out pretty decent.

I'm going through each of my guns, disassembling and soaking them in cleaner (minus the seals, of course). This way, on my next project I can really try to nail my settings. I have recently acquired an old Kelvinator fridge that I'm going to restore, it should be the perfect size to practice on. No acquired positions to spray, just nice straight panels. I'm pretty excited to do it as well.

If anyone else has any answers to my questions in the first post, please let 'em fly! Between advice and practice, I feel like I'm getting there. Even if my spraying isn't always perfect, I'm getting better at diagnosing what went wrong.
 
Mini guns are usually used wide open. I never have liked my LPH80. I'm using my old SATA minijet3 for small stuff.
 
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