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Discussion Starter · #1 · (Edited)
I am sure this question gets asked a ton, but here it goes.

I am having an issue with really only one thing and that thing is this: The PSI coming into my gun is set at 45. I pull the trigger and the gauge on my regulator at the gun inlet drops by 15psi. Now I set this to do just that with the air knob on the gun. Is this telling me that my PSI overall being sprayed with is 15psi?
I also tried this: I would pull the trigger of the gun and set the PSI at the regulator to 45PSI while it was in action, if you will. When I let off the trigger the PSI would return/rise to 60, because of the air knob being set for 15psi.
Which is the right way or am I way off?

The problem I am getting for the most part is when I try to adjust my gun settings I keep losing my spray width. I am trying to achieve around an 8" spray pattern.

I have sprayed before with BC/CC and had the same issue and learned from that due to spraying to heavy of a paint job and clear, which turned into pinning later from lack of solvent coming out properly.

I am stepping up to metallic now on two cars I am painting this week and want to not have that happen again. I do not want to be sanding that much again. The jobs came out nice, but it was a lot of extra work that is not really welcomed this time.

Any and all tips for tuning the gun better than I have in the past would be great. I do not want to kill my new paint job on my 67 GTO Convertible this time around.
I will attach a pic as soon as it lets me, I had one posted in this edit but it disappeared and now I can't.

Thank you,

Brian
 

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The gun psi is set with the trigger pulled. So if you're supposed to set a gun to 23 psi you'd pull the trigger and adjust the regulator until it is at 23. When you release the trigger the pressure reading on the regulator will increase.
 

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Guns

Apart from the gun adjustments when you are getting such a large pressure drop when you pull the trigger, are you using a 10mm hose . I used to use a smaller diameter hose , and suffered a large pressure drop. The gun adjustments on my iwata 400 are fan width and fluid control. Too much air into the fluid stream creates poor coverage.
Cheers
Al.
 

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Discussion Starter · #5 ·
It's a 3/8" hose or 9.5mm. What is the best size to use?

My drop in pressure is only what I set it at with the air knob on the gun. That is what I am trying to figure out, should that air knob be turned in all the way, out all the way, in between somewhere or what?
 

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With the iwata 400 gun i have has the air fully open at the gun so as to atomize the paint properly at the cap. For my style of painting i would end up with sags or runs if i closed the air valve down. My set up is for BC/CC lesonol paint using a 1.4mm needle and cap assembly. ( ratios 2parts paint, 1part hardener, 10% thinners.) Every one will have a different setup depending on their style of painting.9.5mm hose should be large enough if your compressor has a large enough capacity to keep up to your gun. My gun is a HVLP. I also have two water traps. I always disconnect the hose from the gun prior to painting to make sure there is no water droplets there. Before i bought a decent water trap you could see a fine mist of water when the coupling was disconnected.
Cheers.
Al
 

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Discussion Starter · #7 ·
Ya, thanks for the advice. I was afraid of opening that thing up for the most part. I will go back to that and try it with the air knob open. Then re-adjust my PSI at the regulator at the gun.
I have a couple water traps as well in line.
My gun isn't as good as yours and my compressor just meets the guns specs for cfm. I used a smaller compressor that required in that pic of my 67 goat there. I got by and it worked, not sure how but it did, just the paint and clear went on heavy due to lack of proper atomization.

Thanks again.

Brian
 

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I used to open mine all the way open but found some very good advise from Berry K at spi. He has an article on his web site on adjustment that really works. I have been using his method for a the last few years and have really improved my control. To give some perespective, I have been painting for over 30 years and this is some of the best advise I nave received.
 

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Discussion Starter · #9 ·
67Mustang Al,

Thanks for the advise for it worked absolutely great. I will keep reading further for even better fine tuning learning curve, which I assume comes from practice practice practice.

Thanks again,

Brian
 

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Suzuki and Kawasaki bike bits.

I am glad you had a win. Its great when you get ahead of your last effort. My buddy used to own his own bodyworks until the fumes forced him to sell up. He passed on heaps of tips to me before i sprayed the Mustang.I am onto my third gun which is way ahead of the last. iwata400. The mustang was better than my previous effort, but i did a Suzuki fairing last week which was better than the Mustang as it was straight off the gun with a glass like finish. BC?CC
As you say , practice...........
Cheers
Al.
 

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Discussion Starter · #11 ·
Those finishes look great. My clear needs a little work, got just a tad of orange peel, but not much at all, I am going to caulk it up to not enough being laid down. I painted some jams last night and laid the clear a bit heavier than the night before and it came out way better.
I am probaly being held back by the gun I am using atm.
I am very gifted in the drawing department and have an eye and feel for most things artistic, I am 42 now and never did anything with my art skills, it was more of a hobby than a career.
Again, thanks.

Brian
 
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