Help spraying Imron

[Marshall Mahoney]

I've been practicing spraying Imron and can't get a smooth finish. Unless I drench the surface to the point of sagging, the finish is "pebbled." I am using high temp reducer (in specified ammounts) and have varried the pressure in my HVLP gun from 20 to 30 psig, varried my spray pattern, paint/air ratio, and my tip diameter. It's like the droplets don't have time to settle/blend. Thinking about adding more reducer. Has anyone solved similar issues??

Thanks,
--Marshall

[Buju]

Sounds like you're not getting proper atomization of the paint.
The paint/air ratio is where it's at.
My first inclinition would be that you need more material flow. Have you loosened up the cap over the needle, which allows more paint to flow?
What size tip are you using?
Are you using a HVLP unit or a HVLP conversion for an air compressor?

If nothing else is working then yes, thin the crap outta it. Just be aware when you're doing any vertical surfaces.
I can't give you ratios because I'm not very familiar w/ any of the Imron products. I beleive RayboMarine knows Imron like the back of his hand, he should be able to help with reducing ratrios.

[CaptPatrick]

As for potential sags....

All surfaces, especially vertical, need to be sprayed with two coats about 10 - 15 minutes apart. The first coat is called a tack coat and is applied as a full but not quite wet coat. Allow the tack coat to start curing to a tacky stage. When you can lightly touch a finger tip to it and it's tacky but no paint is transferred to the finger, you're ready to shoot the wet coat.

trying to shoot a wet coat without a tack coat under it is begging for a sag...

If you're painting outside, don't shoot when the part is in direct sunlight or overly warm. Best time to shoot outdoors is early morning after any dew has ceased. By ten o'clock this time of year in the south, it's getting too hot to allow the paint to flow before it tacks up. Try to be done with your shoot before the temperature reaches 85ºF

This time of year also calls for use of a slow reducer. That will give you more time before the tack kicks in.

[Marshall Mahoney]

Thanks for the quick advice. I'm thinking that not spraying in the sun makes good sense. The reducer may be flashing off before the paint blends (at 90 deg ambient, I have to be on the upper end of the temperature limits). I won't have time to try it again until weekend after next week...