Iwata LPH400 & Euro Clear

M

MillerMotorsportsLLC

Promoted Users
I currently have a 1.4 LPH400 and am spraying Euro for awhile now. It seems to be a seasonal type clear for me as I have issues when the weather swings one way or another. I have pretty much always had solvent pop issues when doing more than 2 coats no matter the weather. I follow the TDS of waiting 30 mins between coats if more than 2 coats and does not help. I'm only spraying motorcycle parts. My booth is not heated but I do keep my shop at 68-70*. If there is a "big" project in the booth and I run the booth more than usual the temp in the booth can get to 63-65*. I have recently switched to Fast Act due to the time of the year as well. I always use Medium reducer since they're small parts. I would say I also lean towards the heavier side of spraying than lean. I'm beginning to wonder if I am not just putting the clear on too heavy. I have tried adjusting fluid tip in further and it does not seem to help. Would I benefit going to a 1.3 for my clear gun than the 1.4 or is there something else going on?
 
Here' trouble shooting advice from PPG that I saved for my own edification. SPI members here may have other helpful suggestions concerning solvent pop.

Cause

Air or solvent vapour trapped by fast drying paint forming a skin.

This may be due to:

  1. Poor quality or too fast thinner.
  2. Excessive film thickness, or insufficient drying time between coats.
  3. Compressed air pressure too low.
  4. Drying temperature too high, heat source too close to the film, too hot, or applied too soon.


Prevention

  1. Ensure that the surface is scrupulously clean.
  2. Use only recommended thinner.
  3. Apply paint in thin, wet films. Allow sufficient drying time between coats.
  4. Use correct compressed air pressure.
  5. Allow sufficient flash off time before force drying, ensure that the correct drying temperature is not exceeded.
  6. Do not allow the heat source to be placed too close to the surface.
 
MillerMotorsportsLLC said:
I always use Medium reducer since they're small parts.
Click to expand...
IMO there is a good chance that is why you are getting pop. In a booth medium is too fast. Even at those temps. Blend the medium and the slow reducer. Or just use slow. I would also ditch the fast activator. Medium or even slow at those temps.

Another cause of solvent pop is trying to spray with air pressure that is too low. Have no idea what your settings are. As for spraying too heavy this in combination with air pressure that is too low can be an issue.

Search here for Iwata settings as several guys who use them have shared theirs. Compare what you are doing to those settings. Ideally you want to spray wet but not heavy. You should only spray as wet as needed. Watch for the clear filling in as you are spraying. You want it to fill and no more. THat is your ideal speed per pass. Only as much as needed for the clear to fill. Try using less fluid but more overlap. 75% is ideal for most guns and medium/high solids clear.

Stick with the 1.4 as Barry has mentioned that his clears require at least a 1,4 needle/nozzle size. Only exception is the Sata RP as a 1.3 tip is actually closer to a 1.5.
 
Another cause can be insufficient CFM output on your compressor. All spray guns have two call outs for proper atomization to take place. Generally stated something like: 10 CFM at 26 PSI. Any compressor can meet the PSI requirements but only one with a large enough CFM output will supply the correct volume of air the spray gun needs.
 
Chris_Hamilton said:
IMO there is a good chance that is why you are getting pop. In a booth medium is too fast. Even at those temps. Blend the medium and the slow reducer. Or just use slow. I would also ditch the fast activator. Medium or even slow at those temps.

Another cause of solvent pop is trying to spray with air pressure that is too low. Have no idea what your settings are. As for spraying too heavy this in combination with air pressure that is too low can be an issue.

Search here for Iwata settings as several guys who use them have shared theirs. Compare what you are doing to those settings. Ideally you want to spray wet but not heavy. You should only spray as wet as needed. Watch for the clear filling in as you are spraying. You want it to fill and no more. THat is your ideal speed per pass. Only as much as needed for the clear to fill. Try using less fluid but more overlap. 75% is ideal for most guns and medium/high solids clear.

Stick with the 1.4 as Barry has mentioned that his clears require at least a 1,4 needle/nozzle size. Only exception is the Sata RP as a 1.3 tip is actually closer to a 1.5.
Click to expand...
I'll try the blend of medium and slow reducer. I figured with the smaller parts slow would be too slow?

I had very little problems using Medium activator. Recently switched to fast and it has been a hit and miss issue for me. So i'll have to switch back to Medium and see how that goes.

Settings I am at 3 out, fan is at 85-90% open & 28-29 psi
 
MillerMotorsportsLLC said:
I'll try the blend of medium and slow reducer. I figured with the smaller parts slow would be too slow?
Click to expand...
Remember that paint doesn't know what size a part/panel/car it's going on. It will behave the same way if it's a M/C tank or a large Cadillac. If you were painting in a spot with limited airflow then medium would work at those temps. But because you have airflow, medium will flash off too fast trapping solvents. Leading to solvent pop in some cases.
Also you should always turn the booth off immediately after your last coat. As soon as the overspray evacuates. With the issue you are having I would do it on all the coats. Turn it off after each coat of clear as soon as the overspray is gone. That would go a long way to preventing pop. And you really should get the booth and what you are painting to at least 68 degrees. Use a space heater in front of the booth if necessary. They work well, the fumes are not an issue.
 
Chris_Hamilton said:
Remember that paint doesn't know what size a part/panel/car it's going on. It will behave the same way if it's a M/C tank or a large Cadillac. If you were painting in a spot with limited airflow then medium would work at those temps. But because you have airflow, medium will flash off too fast trapping solvents. Leading to solvent pop in some cases.
Also you should always turn the booth off immediately after your last coat. As soon as the overspray evacuates. With the issue you are having I would do it on all the coats. Turn it off after each coat of clear as soon as the overspray is gone. That would go a long way to preventing pop. And you really should get the booth and what you are painting to at least 68 degrees. Use a space heater in front of the booth if necessary. They work well, the fumes are not an issue.
Click to expand...
Also, get your products and gun warmer than ambient. They'll work much better.
 
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