# Does cold weather affect exposure time?



## jerryperrish (Jun 17, 2008)

I've been using performance screens s.e.x. Emulsion for a while an have been extremely happy with it. However, for the last week or so I've had a terrible time getting screens to expose properly. The only variable that I can think of that has changed is the weather. 

Does exposure time change with the weather?


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## kc6789 (Mar 28, 2010)

It depends where u r keeping your screens while the emulsion dries. If they r just sitting in the dark, cold garage (like mine r currently) then they might need a bit of heat to help them dry. I just have a space heater next to them. I haven't had any problems.


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## PositiveDave (Dec 1, 2008)

I agree, it's more likely to affect the drying than the exposure.
Strangely, the air at 0C contains less water than at 20C, so in winter when you bring cold air in and heat it up the relative humidity drops to about 20%. This gives static problems but aids drying.


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## selanac (Jan 8, 2007)

Jerry, 

I'm in NJ and also use Performance Screen S.E.X emulsion. I haven't had any problems yet. I use a space heater, Flash Dryer and Conveyor Dryer to warm up my shop. When I coat the screens, I do it just before I leave, and let them dry over night. I don't have heat in the shop except for what I mentioned and that's only while I'm in the shop. 

I have a 400 watt setup and it takes about 14 minutes if I coat both sides once. I then wet the t-shirt side for a few seconds (running water) then turn it over and let water fill up. I let everything sit, and come back in five minutes and wash out the screen. No problems.


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## jerryperrish (Jun 17, 2008)

Thanks for the replies! Especially selanac, because we have the most similar environments. Just to be clear, you literally fill the inside of the screen with water and let is soak for 5 minutes? I have never thought of doing that.


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## selanac (Jan 8, 2007)

Not litterally cause the ends of the screens don't have emulsion. When you coat the screen, the coater isn't suppose to touch the frame. That's one reason we use tape.

Otherwise yes, I let it set for about 5 minutes. It cuts down on the washout. You'll start seen the emulsion come off the image right away.

Also, you can ask Bob at Performance Screen anything. He's really knowledgible and willing to help. He was the one that told me to put a coat on both sides. Though I heard of people doing only one, he said it's smoother for the screen.


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## kc6789 (Mar 28, 2010)

selanac said:


> Jerry,
> 
> I'm in NJ and also use Performance Screen S.E.X emulsion. I haven't had any problems yet. I use a space heater, Flash Dryer and Conveyor Dryer to warm up my shop. When I coat the screens, I do it just before I leave, and let them dry over night. I don't have heat in the shop except for what I mentioned and that's only while I'm in the shop.
> 
> I have a 400 watt setup and it takes about 14 minutes if I coat both sides once. I then wet the t-shirt side for a few seconds (running water) then turn it over and let water fill up. I let everything sit, and come back in five minutes and wash out the screen. No problems.


Sex!?!? WTF!?


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## selanac (Jan 8, 2007)

Yes, don't know what the initials stands for. It's great stuff, and no Diazo. I don't even have to mix it very well. All I do is pick up the container, move it around in a circle a few times, let it sit, and start coating. No air bubbles either. 

They have a site in Utah I think for all of you on the West Coast.


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## kc6789 (Mar 28, 2010)

selanac said:


> Yes, don't know what the initials stands for. It's great stuff, and no Diazo. I don't even have to mix it very well. All I do is pick up the container, move it around in a circle a few times, let it sit, and start coating. No air bubbles either.
> 
> They have a site in Utah I think for all of you on the West Coast.


So it's not sensitive to light?


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## Jsaladin (May 23, 2010)

no one has mentioned this yet but unless your exosure time all of a sudden changed it could be the light you are exposing with. Depending on my volume I change my bulb every 3 months or so.


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## lemoid (Dec 22, 2010)

Also pay attention to your stencils, maybe they're not too dark so light passes through.


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## selanac (Jan 8, 2007)

KC, yes they're light sensitive. The Diazo is an activator I believe. With S.E.X emulsion it's pre-mixed. Last for about a year on the shelf.


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## kc6789 (Mar 28, 2010)

selanac said:


> KC, yes they're light sensitive. The Diazo is an activator I believe. With S.E.X emulsion it's pre-mixed. Last for about a year on the shelf.


It's "Super EXposing Photopolymer"
Y not SEP? We'll never know lol. 

Where do u buy it from? Good price?


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## selanac (Jan 8, 2007)

KC. I buy it from Performance Screen.com When you go to their site, you have to download their PDF catalog. It's a pain.

For the most part, they're a little high. The main office is the closest screen printing supply company to me. I'm a big believer in buying local if I can. 

Also, Mark the owner gives good tips. They have a Satelite office in Utah I think. When I go there I feel like a kid in a Candy Store.


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