Having trouble spraying pearl. Mottling, blotching

R

Rgn1133

Hi, new to the forum because I need some help. I'm spraying crystal silver pearl over a light blue solid using a iwata lph 400 gun. I've sprayed pearls before with no problem but this time I'm getting mottling/blotching, what I call splotching in it. Using mason paint, 441-21 reducer. Spraying at 12lb pressure at gun inlet, 4-6 inches away with all settings at full open. Outside temp is in the low 80s. HELP!!! What can I do to make it lay down flat like it's supposed to. Thanks for your help!!!
 
Sounds like you are spraying it too wet. Spray it more like it's a basecoat. That means turning in your fluid knob. Reduce your material, bump your air pressure, move faster. If you are still having issues over reduce it or use some wet-bed/blender to over reduce it. You will have to increase the number of coats to get the same effect though, but that should make it easier for you to spray it. Doesn't hurt to do that for the last coat of pearl as it'll help even out any blotchy or mottling spots.
 
what chris said. also, your probably a little close to the panel with that gun. 6" is ok but 4" for laying down a pearl is too tight. your psi sounds quite low also. an lph usually runs about 20psi at the gun with the trigger pulled. the idea is you want to spray the pearl a little drier. the paint should not flow out.
 
Thank you for the help. Ok. So adjust my fluid knob in for less fluid and move faster. That's about the only thing I haven't tried. My pattern knob on this iwata is wide open also. Should I try turning it down too?
The basic set up for this gun says not to exceed 14lb pressure at inlet. Have you found this to work or should I bump it up higher?
 
Rgn1133 said:
Thank you for the help. Ok. So adjust my fluid knob in for less fluid and move faster. That's about the only thing I haven't tried. My pattern knob on this iwata is wide open also. Should I try turning it down too?
The basic set up for this gun says not to exceed 14lb pressure at inlet. Have you found this to work or should I bump it up higher?
Click to expand...
The 14 psi is to meet the Gov. regulations. As we know, speed limit signs are more if a suggestion. As is the 14lbs.
 
Double check your gun spray-out pattern on a piece of paper quick after any adjustments. If its not even across the spray pattern you will get blotchyness with pearls easy. Like others said, less is usually more in this case. I usually shoot my pearls in Intercoat mixed 2:1. Some slight adjustments and youll get it!
 
So is it a good idea to turn the fluid knob in to reduce the width of the pattern on metallic base coats also??
What about solid colors?
I’m a pretty experienced sprayer but I’ve never had this happen and can’t seem to get the right adjustment and now I’m second guessing everything.
So pressure up to around 18 for pearl and turn fluid knob in to reduce pattern width, stay 6in away and move faster right?
I’ll try it. Thanks for the help
 
pretty much what coronet said on the gun. i have been spraying all my base with an lph400 for 15+ years and not once have i sprayed at less than 19lbs. the purple cap is the only one that says 14lbs. orange cap is 16 and silver is 19. i run them all about 20. keep the fan wide open. just dust the pearl on. base of any kind never gets sprayed as a wet coat.
 
Ok. I have a 1.3 tip. Should the pressure be any different because of that??
 
At What distance do y’all spray from the panel for any basecoat? 6? How many coats of base does it take to cover and flatten out?
 
Around 6 inches. 3 coats is equivalent to OEM pearl finishes. More or less depending on what you are trying to do.
 
Ok. So I just sprayed crystsl silver pearl on a test panel. I set the fluid knob at 3 turns out from closed. Psi at 18 at inlet. About 6” distance and moved fast. Put 2 coats on and still mottled and blotchy. Suggestions? I have never had trouble with pearl before but this is kicking my butt this time.
 
At this point I don't really know what else to tell you, so I'll go over the basics. Don't take this the wrong way but you sound inexperienced, so I'm gonna try and get you pointed in the right direction with some basic info.
First, how are you reducing it? What ratio? Did you get the pearl from your jobber? Or did you mix it from mixing bank in your shop?
Next question, what color is your base that you are shooting the pearl on?
Next question, are you being consistent with your overlap? How much overlap are you doing?
You need to spray it like a basecoat. If it's still blotchy that means too much material still or you are moving too slow. Or it could mean your tracking and overlap is inconsistent. I suspect it's a combination of the 3.
You should know how to adjust your gun, read this article by Barry. https://www.southernpolyurethanes.com/adjusting-your-gun when you have finished read it again.
So spray it like a basecoat. 6-8 inches away from the surface. Try holding it farther back. Closer to 8 than 6. Be consistent in your tracking. Draw invisible straight lines in your head through the car. Follow those lines when spraying, meaning don't follow body contours, spray in a straight line, be consistent with your overlap. Tighten up your overlap from what you were doing earlier. Don't panel paint, walk the entire length. You are not trying to lay it down wet, just pretend it's a basecoat. Make sure you are reducing it correctly. Consider over-reducing it in order to help you spray it. Thats all I can think of at the moment.
 
I had decent luck with Nason solid basecoat and single stage on a few jobs 10 years ago. Tried their metallic basecoat one time on a light gold hood and never got it to look right (mottled/blotchy). Never used Nason again and fortunately have not had a problem with metallics since. I would assume spraying a Nason silver pearl is going to be tough.
( I know this is no help for you, just my experience with Nason.)
 
Like I said above if your panel is blotchy after spraying several coats, try reducing it with preferably "wet-bed" aka blender or if you don't have any of that use reducer. Try it at 1:1, 1 part of your RTS pearl to 1 part reducer. Spray one coat and let it flash. Then look at it and see how it looks. If you still have problem areas, then spray a second coat.
 
You are right. We ( my dad and my brother) build cars, street rods, in our garage for ourselves. We are not professionals but we do quality work. We have done this all our lives. We do all of our own work, frame, body, paint, interior etc. So we don't paint all the time. It's not our regular job at all. So yes we are inexperienced in that regard. We have painted quite a bit though. But this is something we've never experienced. We have never had a problem with pearls or anything since buying this iwata gun about 10 years ago. The last two trucks I painted were both pearl. One a green pearl over a solid green. And one a silver pearl over white. All Nason. No problems. Smooth and even all over. Went on great.
I've made sure of my overlap, I do the invisible line as well as have my brother watch and tell me when I'm off. I cut the pearl 2:2 this time also. Should I cut the fluid down another turn and back up? I'm about 6" away. Should I be more? It's driving me crazy because I've done this before with no problems.
I have used all of my left over paint working on this gun. I can spray solids and metallics of any color with no problems. I even had some white diamond pearl and some green pearl left over and both of those spray out perfect. No blotch no nothing. But when i put this crystal silver in it goes on like crap!! I'm lost!!!
I appreciate you time and effort in helping. Thank you.
 
Not trying to interrupt, but I feel it's along the lines of the conversation.

If I recall correctly, Barry once said he feels one of the main causes of adhesion issues is spraying the base too dry. In this conversation many respected painters are saying spray it dry. Does anyone happen to have pictures or a video of what they feel the correct "wetness" is of a basecoat being sprayed?
 
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