SPI White epoxy mixed, then separates over night.

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danford1

I have a qt of SPI white epoxy I bought a few years ago (can't remember when exactly). It was opened for the first time yesterday. Of course the pigment settled and it took a long time to stir it until it wasn't lumpy.
I used an open gallon can of activator that I used about a year ago. It has a dark amber color to it.
I mixed up the equal parts A&B stirring well, let induce for 2 hours stirring occasionally as I got the garage ready for spraying. Garage temp set at 70 degrees, infrared temp of metal parts 68-69 degrees.
I'm spraying minibike rims and misc parts. I hung 18 pieces and sprayed on a wet coat. I went in the house for a couple hours to let it flash.
When I went out to spray the 2 nd coat I noticed the mixture in the container had settled a little as it had a thin layer of amber on top. I didn't think much of it, I stirred it, it looked fine so I poured it into my gun and sprayed it.
This morning when I went in the garage (I set temp to 73 degrees for the night) the mixed epoxy in the container had separated to equal parts white and amber liquids. Is that normal?
I then thought if it separated in the container what about my parts? I checked them. They look fine and feel fine. They seem dry and not sticky at all.
I stirred the settled container and it stirred up good, no problem.
This is the first time I used white. I always used black or red before and never noticed and separation.
Am I in trouble with the 18 parts I sprayed?

Danford1
 
That is normal. Now you know how important it is to mix your epoxy well, no matter what color it is. Red or black do the same thing, you just can't see it like you do with white.
 
I use SPI white epoxy alot more than grey. This is normal. Just make sure to mix good again before spraying and you will be OK.
 
Thank you !
I was hoping that it was normal. Whew... that is one less thing to worry about. I was dreading having to sandblast the parts and start again. I feel much better now :)

Danford1
 
Epoxy and pigments don't stay stable long, it can be fixed in manufacturing but at the expense of the next product adhesion..
o we use less pigment dispersing additives.
 
Barry, can you give me a quick explanation? Why will the mixture separate in the container overnight but not separate on the part it was just sprayed onto?

Thanks
Danford1

PS I sprayed 30 more parts yesterday with Black epoxy. I looked at the remaining mixture in the container today and couldn't see any separation. Probably because it was black...
 
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