# drying time for emulsion



## nevermind (Dec 14, 2006)

I have a drying box running at about 95 degrees and 50% humidity. How long should it take to dry screens?

I think I am leaving them in too long and baking them??


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## CustomScreen (May 3, 2007)

the best way to dry screens is with a dehumidifier, drys them pretty quick and won't overbake them, to much humidity can make the emulsion run or breakdown.


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## nevermind (Dec 14, 2006)

Thanks - how quick is quick?


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## CustomScreen (May 3, 2007)

with just a dehumidifier it can take an hour or so, you can also put a heater in to speed things up, i normally try and leave the screens overnight if i can help it, or i've found if you need one extra quick, a hairdryer does the job in maybe 5mins.


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## Fluid (Jun 20, 2005)

In our darkroom we have a dehumidifyer and fan. We can dry a freshly coated screen in about 5-10 min depending on how many screens are in the room freshly coated or freshly reclaimed and waiting to dry.


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## RichardGreaves (Nov 7, 2006)

nevermind said:


> I have a drying box running at about 95 degrees and 50% humidity. How long should it take to dry screens?
> 
> I think I am leaving them in too long and baking them??


Stencils can never be too dry, they can over heat and crosslink. This happens at temperatures over 110F

Dry is better than heat, but 95F is not bad. Not as good as 80F, but not bad. A Dehumidifier dries the air and the dry air sucks the moisture out of the stencil. 

A box is probably sealed. Where will the water go?

Nobody can tell you how long, they can only guess. YOU, but a $19 Indoor/Outdoor digital thermometer/HYGOmeter at Radio Shack. Model: 63-1032

Over night the box will stabilize. Put in a screen, close the box and watch the humidity of the air go up. When it stops going up, the air in the box has done all it can. You might as well take the screen out.

IF you dehumidify the box, or the whole room - The room will stabilize overnight and be as dry as the dehumidifier can make it. When you put a coated screen in the room/box, the humidity will rise and then fall back low humidity as the dehumidifier gets the air back to dry.

How long? 1 screen would be different from 5. Rainy day, different from winter. 

The hygrometer has no friends. When the hygrometer returns to its low, the screens are as dry as you can make them. 

Sears. $150. I say a dehumidifier is the fastest way to dry your screens.


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## BlackLegends (Aug 14, 2007)

CustomScreen said:


> with just a dehumidifier it can take an hour or so, you can also put a heater in to speed things up, i normally try and leave the screens overnight if i can help it, or i've found if you need one extra quick, a hairdryer does the job in maybe 5mins.


How close or how far away should I have the hair dryer? I hate to do it this way but I need this screen dried quickly, like today. I dont know what happened with the last one I did. I think maybe I had too much emulsion on the screen. After I exposed it I began to wash it out. At first the design was coming out pretty well. Then all of a sudden all the emulsion started peeling off. There was also this awful smell after exposing. This is my second time doing this process (coating, exposing, printing). The first time everything went perfect, guess thats why Im catching so much hell now.


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## RichardGreaves (Nov 7, 2006)

BlackLegends said:


> How close or how far away should I have the hair dryer?


Use the baby bottle test to compare hot liquid to 90 degree F skin temperature as a safe test. If the stencil feels hotter than your wrist, you could cause damage to the stencil or it might crosslink areas with heat that you want to wash out.


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## BlackLegends (Aug 14, 2007)

Thanks, Im about to try it out now.


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## kylerogers (Jul 30, 2008)

I just bought a dehumidifier from Lowes for $150. It puts out a lot of heat as well as sucks out the humidity. So I'm working in a small room and the dehumidifier is actually heating up the room. Right now it is 78 in my house. I have the central air vent closed to the room where the screen is drying and it's 91 right now, cause the air blowing out of the dehumidifier is hot.


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## RichardGreaves (Nov 7, 2006)

*Hot in screen storage room*



kylerogers said:


> I just bought a dehumidifier from Lowes for $150. It puts out a lot of heat as well as sucks out the humidity.
> 
> So I'm working in a small room and the dehumidifier is actually heating up the room. Right now it is 78 in my house.
> 
> I have the central air vent closed to the room where the screen is drying and it's 91 right now, cause the air blowing out of the dehumidifier is hot.


Cool air can hold less water vapor than warm air. This is the reason common humidity is measured as relative humidity. The amount of moisture that air can hold is realtive the that actual temperature of the air.

Open the central air vent and cool the room if you are uncomfortable. The dehumidifier will remove the moisture easier.


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## miktoxic (Feb 21, 2008)

man i'd love to know the REAL answer to this question if somebody could actually speak english.


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## Fixico (Dec 3, 2011)

In a closet or small 74 degree room with a fan and one of those little dehumidifier canisters from the dollar tree, your screens will be dry in about 1- 1 1/2 hours. If you need it now, take a blow dryer on the warm setting to it for about 5 minutes.


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