# emulsion dry one side, sticky other side



## matsu (Jul 13, 2011)

Hey everyone,

I started noticing that whenever I burn a screen and I wash it out the exposed side is dry and clean. However, the print side is sticky and the emulsion is usually running causing a lot of scumming?

I never had this problem when when burning screens before. It has been getting worse and worse and I can't figure out what i'm doing wrong. I am using the hifi emulsion by ryonet.

underexposing? bad emulsion? weather?


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## lben (Jun 3, 2008)

Could be you are putting more on one side and not letting it dry enough before exposing. I let my screens dry for 24 hours before I use them. Humidity (too much) will also interfere with emulsion drying. You might also be spending too much time washing out one side and the emulsion is getting water logged. After I wash out a screen I dry it with newspaper and then set it back on the rack for several hours to dry some more then I re-expose them to harden the emulsion. Do you coat both sides of the screen? I do.


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## sben763 (May 17, 2009)

Under exposing. What is your light source. Also if its humid its possible its not drying all the way. Best to be under 50% humidity when drying hi-fi and if it gets higher the 65% I get it below 50 and run in dry box for at least 2 hrs before exposing. 

If your using a unfiltered black light florecent exposure unit. If the bulbs have a dancing effect when on they need per warmed as they are not putting out full UV power if cooler.


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## GKitson (Nov 8, 2009)

Underexposure is probably the culprit.

"Under Exposure test for dummies", after you have washed out the screen to your satisfaction take a white paper towel and wipe it across the squeege side of the screen, if you have any color transfering from the screen to the paper you are underexposed, simply increase exposure time unitl no color transfers to the paper.

After you do that test, learn how to do a proper exposure calculation and consider how much time yhou are wasting 'babysitting' bad screens.

Time is money has never been more true than in this example.

Good luck.


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## sben763 (May 17, 2009)

The Ryonet Hi-Fi (CCI PRODUCT) can give an under exposure indication while it still is exposed properly if the humidity is too high. Essentially it is under exposed as wet emulsion isn't as light sensitive as dry emulsion but if not at proper humidity levels no amount of exposure time will correct the problem. A indication that humidity level may be too high is if some of the ink from your positive transfers to the emulsion during exposure.


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## matsu (Jul 13, 2011)

Im using the 20x24 exposure unit from ryonet. After washout i can't even dry the squeegee side with a newspaper because that side is way too sticky and it smears the residue onto the parts that was washed out. 

I put on the same amount as the non print side. Also I am exposing for the amount of time it tells me to that came with the exposure unit instruction for the hifi.


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## sben763 (May 17, 2009)

Are you in a colder location. Pre warm your bulbs. Even at 65 the output on the bulbs is lower. Letting it run 4-5 min before exposure your good. The instructions are for a 1/1 coating with sharp side. Basically a thin coat. If you getting a thicker coat you'll have to extend tour time. 

You are coating shirt side first then you ink side correct. On the ink side I use slightly more pressure as you want to push the majority of the emulsion to you shirt side. I have a 25x36 exposure unit. and expose in 2:00 for a 1/1. 3-3:30 for a 2/1. When I do a 2/1 I actually do a 1/1 and then do a coat after dry just on the shirt side. 

As long as you know the humidity is low and the screen is completely dry you are under exposing the screen. The reason the shirt side is dry and the ink side tacky is your not exposing all the way though. You do not want a thick coat on your ink side.


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## matsu (Jul 13, 2011)

Well the weather has been colder lately and I never used to have this problem during the summer. Also I never warm up the bulbs so maybe that might be the issue.

Using the hifi- for a 160 mesh(1/1) Im exposing it for 1:30. 

I feel like it might be that its not exposing all the way through like you said leaving the ink side sticky. You think I should try exposing it for a little longer? 15 secs? Thanks again for your help! 



sben763 said:


> Are you in a colder location. Pre warm your bulbs. Even at 65 the output on the bulbs is lower. Letting it run 4-5 min before exposure your good. The instructions are for a 1/1 coating with sharp side. Basically a thin coat. If you getting a thicker coat you'll have to extend tour time.
> 
> You are coating shirt side first then you ink side correct. On the ink side I use slightly more pressure as you want to push the majority of the emulsion to you shirt side. I have a 25x36 exposure unit. and expose in 2:00 for a 1/1. 3-3:30 for a 2/1. When I do a 2/1 I actually do a 1/1 and then do a coat after dry just on the shirt side.
> 
> As long as you know the humidity is low and the screen is completely dry you are under exposing the screen. The reason the shirt side is dry and the ink side tacky is your not exposing all the way though. You do not want a thick coat on your ink side.


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## sben763 (May 17, 2009)

If your using fluorescents prewarm bulbs also florecents loose power overtime. The first 5-10 hrs at 100%. From 5-50 and as high as 100 hrs 80%. After that they will start to rapidly loose power. Some bulbs last longer some don't last long at all. If still having issues yea bump 15-30 sec.


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