Why does my epoxy look like I rolled it on?

DanMcG

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I put a couple coats of epoxy on a door today and it came out fairly nice and smooth. That is until I emptied out about an ounce that was left in the cup on the window frame and got this.
texture.JPG

By the time I got around to doing this last little bit it was in full sun, if that make a difference.
Any suggestions on what I'm doing wrong here?
Pressure is 26-28, fluid is 2.25 turns for fully closed
 
Looks like you ran out of paint and went over the wet application with only air coming out of the gun.
 
Sorry no, the coat that I applied this to had dried for 30 plus minutes. and that's basically how it when on, with large droplets that never leveled out.
 
Did you use a standard cup or a disposable system? Did you remove the strainer from the disposable cup? Barry recommends removing that cup stainer. Did you remove the strainer that is usually found in the gun body? What size needle set?
 
Standard cup with no gun filter. The needle is a 1.4
Would a low air pressure at the gun do this? I'm wondering if I bumped the pressure down without knowing it.
 
I don't know if this is the problem for sure, but I want it to be known that you can't leave epoxy sitting in the gun for 30 minutes. It has to be poured back in a cup, the gun nozzle must be cleaned at least a little, and the epoxy needs to be stirred and returned to the cup when it's time to spray again.
 
Standard cup with no gun filter. The needle is a 1.4
Would a low air pressure at the gun do this? I'm wondering if I bumped the pressure down without knowing it.

I could see it doing that if the fluid was wide open and air pressure was low. Like you said, maybe you bump the guns air pressure knob?
 
Ha, No I left it in the gun. I wipe the nozzle down with lacquer thinner when I finished the previous coat, then before the last round I spun the gun around to mix the remaining paint in the gun cup and sprayed.
I'll start cleaning between coats, but if I can leave it on my bench for days in a sealed cup why not in a sealed gun?
 
Ok I’ll take a SWAG at this. If you only had one ounce of paint in the gun then you had that small volume of paint with a large exposed surface area. So that small volume of epoxy flashed off a significant proportion of its solvents, thickening it considerably.

One ounce is a pretty small volume of paint no matter where it sits for a half hour.

Don
 
Ha, No I left it in the gun. I wipe the nozzle down with lacquer thinner when I finished the previous coat, then before the last round I spun the gun around to mix the remaining paint in the gun cup and sprayed.
I'll start cleaning between coats, but if I can leave it on my bench for days in a sealed cup why not in a sealed gun?
Because it settles. I presume that like most of us, if you leave it on the bench you stir it before putting it in the gun, but if it's left in the gun, it settles down in the needle/nozzle area, and it can't be stirred.
 
Thanks guys, I appreciate you taking the time to shed some light on my problem, and after reading you posts I feel a little foolish that I didn't figure it out myself.
 
There is a lot of tempation to leave material in the gun between coats, and when you are dealing with materials that have flash times under 15 minutes, it's usually not a problem. But epoxy is a different animal, with a minimum flash time of 30 minutes and also a propensity to settle. This makes it very important to remove from the gun between coats.
 
Learn from me as well. I use PPS cups. I shot some epoxy, left the epoxy in the cup removed from the gun(with a cap over the top) which I have done many times. Forgot to clean the gun and went home. Came in the next day, tore the gun down, cleaned it completely. Opened the PPS cup and stirred as usual, went back in and started spraying. Sprayed great then shot out a nice a stream of spackle...... The epoxy had thickened in the neck of the PPS cup(between the strainer and spout).


I guess I forgot to remove the screen, then neglected to use a new lid. Luckily an easy fix.
 
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