# Photo emulsion is too thick, add water?



## pm17 (Jan 8, 2013)

hello everyone. 

I need some help. I bought a Diazo photo-emulsion several months ago and printed a few shirts and then didn't use it for quite a bit. When i tried to use it again last weekend, the emulsion was way too thick. I burned my image anyway (using the same system I had in the past) and my whole screen washed out, there was only a ghost image left on my screen. I tried this twice, same deal.

I think this may be because the emulsion is so thick i couldn't get a thin even coat on my screen. If I add a little bit of water to the emulsion, will this fix the problem or ruin the emulsion?

Thoughts? Thanks for your help!


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## Hegemone (Oct 18, 2011)

I think it's trash or your bulbs are trashed. I have seen this for both these reasons. Adding water will contaminate and cause curing issues in my experience. 

My two cents. Toss them in a well and make a wish.


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## Big City (Feb 23, 2012)

usually this happens if it is getting old or in my case when it happened it was to warm in the room were i left the emulsion.with this said it is almost always ruined time to buy some new stuff. you could always dump a little emulsion in to a bowel mix a little water with it and see what happens when you coat the screen not sure if the properties in the emulsion will have broke down to much at that point or not but a cool experiment that you can tell us all about.some times that is how the best lessons are learned when one is screwing offlol


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## tman07 (Nov 14, 2007)

Emulsions that are sensitized have a shelf life of about 30 days,
that might be the problem


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## deepbluex (Jun 24, 2011)

tman07 said:


> Emulsions that are sensitized have a shelf life of about 30 days,
> that might be the problem



I've been seeing this information in a lot of places BUT... I've used dual cure (DXP) emulsion that was a good 4 months beyond the sensitizing date and it performed fine with no additional exposure time. The emulsion flowed a little thicker from some evaporation but it didn't go bad. I live in California where my shop's ambient temps go from 65-85F daytime to 55-65F night. No special storage.


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## sben763 (May 17, 2009)

tman07 said:


> Emulsions that are sensitized have a shelf life of about 30 days,
> that might be the problem


The OP is using photopolymer which usually has a shelf life of 1-2 years. It sounds like the container wasn't sealed or may have received some very old emulsion. 



deepbluex said:


> I've been seeing this information in a lot of places BUT... I've used dual cure (DXP) emulsion that was a good 4 months beyond the sensitizing date and it performed fine with no additional exposure time. The emulsion flowed a little thicker from some evaporation but it didn't go bad. I live in California where my shop's ambient temps go from 65-85F daytime to 55-65F night. No special storage.


I've used the DXP 9+ months with cold storage. 38-45F I used it cold but I've seen where other say to let warm up before coating. I now only use photopolymer.


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## deepbluex (Jun 24, 2011)

I like photopolymer but I've discovered the Waterbase safe stuff and it has been performing well for me for waterbased discharge and plastisol. They're the same price so I just stick with that - I like the water resistance even though I use waterbase less often than plastisol.



sben763 said:


> The OP is using photopolymer which usually has a shelf life of 1-2 years. It sounds like the container wasn't sealed or may have received some very old emulsion.
> 
> 
> 
> I've used the DXP 9+ months with cold storage. 38-45F I used it cold but I've seen where other say to let warm up before coating. I now only use photopolymer.


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## sben763 (May 17, 2009)

deepbluex said:


> I like photopolymer but I've discovered the Waterbase safe stuff and it has been performing well for me for waterbased discharge and plastisol. They're the same price so I just stick with that - I like the water resistance even though I use waterbase less often than plastisol.


Not all photopolymers are created equally. I use Satti Chem PHU which is waterbase and discharge compatable. One of the few. I personally don't like the 2-3 min exposure time with dual cure. I'm exposing 30-45 sec with photopolymer. One of the biggest issues with photopolymer is humidity control. I think the Saati has a 2 year shelf life. I have in the past had suppliers send dual cure that either was bad from the start or it only lasted 30 days The Satti gives the best halftone results of all the photopolymers I have tried to date.


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## galmiklos (Mar 30, 2011)

I know it's an old thread, but that's exactly the point to my comment. Since the last post is from 2014. Well, I had a pint of Ulano Orange from 2014, I suppose at this point the month doesn't really matter, does it? ;-) Anywyas, it was pretty thick, so I diluted it with tap water, just by ear, coated a screen, and it performed exactly the same way it did 5 years ago. I used the exact same lamp, from the exact smae distance, for the exact same time, and the print came out perfect. I am printing printed circuit boards, and the one I printed with this old emulsion is full of SMD components, and 8 mil traces with 8 mil clearance, with means very dense, high resolution. It worked!


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