Ink from Film Sticking to Emulsion

[Racer Tees]

Trying out some Aquasol HVP this week.  Been using some Tex Blue from a local supplier.  The ink from the film is sticking to the emulsion after exposing.  Only thing that has changed is the emulsion.  If you reclaim it comes right off.  Exposure looks good except for the black ink stuck to it and the otherwise now worthless film.

I'm about a dozen screens into the bucket when this happened.  I love it compared to what I had before, but I'm lost on this.

What would cause this?

[mk162]

my guess...your emulsion isn't dry enough.  I've had this problem with other emulsions, but never HVP

[ericheartsu]

When we were using films this happened to us alot. We still couldn't really find the source of it, aside from possibly the humidity in our ink room, or the films getting to hot while exposing.

for us it was happening on screens that had been sitting upwords of a week before being exposed!

[Racer Tees]

I was thinking someone was gonna say humidity.  I'm at like 55% humidity in my screen box.  Might be time for a Dehumidifier?

[ericheartsu]

ours was at 40% and it was still happening

[Racer Tees]

Small heater in dry box and dehumidifier in the room.  Should help?

[T Shirt Farmer]

IMO it is caused by heat from the bulb coupled with whatever humidity is in the emulsion. The day I went LED the problem immediately went away with very few exceptions of a freshly coated 110

[mimosatexas]

Still happened to me even after I built my new screen room which is a constant temp of 72-78 degrees and 35-40% humidity, even if the screens had dried for a month and the films had been left in the same room.  Happens more on thicker stencils/lower mesh.

SP1400 I can coat, dry for 20 minutes, and expose without issue.  Longer exposure of course.

[Racer Tees]

IMO it is caused by heat from the bulb coupled with whatever humidity is in the emulsion. The day I went LED the problem immediately went away with very few exceptions of a freshly coated 110

Well.  I plan to go LED in the near future.

Still happened to me even after I built my new screen room which is a constant temp of 72-78 degrees and 35-40% humidity, even if the screens had dried for a month and the films had been left in the same room.  Happens more on thicker stencils/lower mesh.

SP1400 I can coat, dry for 20 minutes, and expose without issue.  Longer exposure of course.

What is your exposure time difference from HVP to SP1400?


This literally just came off the exposure unit.  Washed out perfectly.....

[Frog]

I have had this issues with films fairly fresh off of the printer, and certain emulsions that just seem "tackier" than others. (These same emulksions also tend to reclaim more like bubble gum)

Band-aid fix is lightly dusting with talcum powder.

On the other hand, many don'r even bother to catalog films any more with output being so easy (compared to the days of stat cameras) So, as long as a screen works, the damaged film may not be as much of an issue.

[Racer Tees]

I don't mind the damaged film as it's not a big expense.  But these designs will be reprinted about once a month all year....

[mimosatexas]

"Proper" exposure time is a little less than double for SP1400 on my setup, though for plastisol runs I can expose them almost the same honestly and have no issues, but it isn't a full exposure.  I run lots of discharge though and prefer to just have single times per mesh/coating vs switching it up at random and possibly running into an issue.  I have found with the 1400 I can expose it a really long time and not see much undercutting or loss even with 55lpi halftones.  If I know I'm doing a long run of DC white for example, I will "over expose" just to be sure it has no breakdown.  I am using a 1k MH though, so I would expect on something stronger the exposure difference and the need to "over expose" would be different.

[Shanarchy]

I rub a little talcum powder on all my screens before exposing. It solved that problem for me. My problem was humidity in the summer. It was actually causing the film to stick a little.

[Gilligan]

We had issues like this with chromablue, baby powder is what we used?

[Itsa Little CrOoked]

I've had it too. A dehumidifier in my darkroom was the fix for me. Even still, if it's raining and I go right from film output to exposure it might still happen. I am convinced it is humidity.

I didn't like talc, but on films I MUST catalog, I've sprayed Krylon Matt Clear on the films with good result. Test on films you can easily reproduce.

To state it again, this problem ONLY happens to me when I'm rushing the films, AND/OR the emulsion isn't dry enough, for whatever reason. Foggy weather has even cause it.

My 2 cents.