[nikki07]

I recently used some emulsion that has been sitting non-refrigerated for about 3 months. It's SPS ex1 emulsion. I coated 6 screens so far and have only been able to use one because all the others have washed out the design (as in underexposure, but i am using the same exposure time and even tried over exposing with the same result) and had these "streaks" of easy to wash out and hard to wash out areas, one washed out and looked like i had dripped emulsion remover on it (which i didnt).

Should I throw out the emulsion, or could it be something else?

Thanks!

-Nicole

 

[rockersuk]

if its dual cure i would bin it!as it only lasts about 2 months max

 

[nikki07]

Okay. Is that 2 months after I open it or does it go bad even unopened? (The one I was using was opened, I am just wondering whether or not to stock up on emulsion)

-Nicole

 

[ScreenFoo]

I'd just point out that if you have streaks that are easy to wash out, and some that aren't, you may be coating unevenly, or perhaps the diazo wasn't properly mixed initially. I think it depends on the emulsion, as well--I got nine months (refrigerated) out of a batch back when I was playing around in school--not to say it behaved well near the end of that period...

If you got one screen to work, you've proven it can still work, if you are controlling your variables. With less than optimal equipment, it may not be worth your time to try, however.

 

[splathead]

Okay. Is that 2 months after I open it or does it go bad even unopened?

Two months max after you mix it.

 

[nikki07]

When I used the emulsion 3 months ago it was fine, so I don't think it was mixed unevenly. I could have coated unevenly but this type of thing happened on 5 of the screens so I doubt it. The one I did manage to use wasn't even that great, it still had the streaks but they were in an area outside the image so I used the screen anyways.

Thanks for your help! I coated the screens again with brand new emulsion and they are drying now, I will let you know what happens.

-Nicole

 

[nikki07]

Just made a perfect screen with new emulsion - - the other stuff was just bad. Thanks everyone!

 

[ScreenFoo]

Hmmm... if the emulsion was just bad, I wonder why the one screen did work?


​

 

[nikki07]

Well like I said, that one was still a bad screen. There were streaks on it and it washed out way too easily, but the image was only thick letters so i managed to use it anyways because the streaks were in a different area.

 

[ScreenFoo]

That makes sense, for sure.

Nothing worse than when something works once out of five or six times, but you have no idea why... but when it only kinda works, it's not so bad.