[Wreker36]

I was wondering if led lights are light safe for working in while coating and exposing screens

thanks dave

 

[sben763]

That will depend on the led some LEDs put off UV. I use 4ft standard fluorescents overhead. Although fluorescents put off UV they have a filter and at a few ft it would take days to expose the emulsion

 

[Wreker36]

thank you for your help

 

[chuckh]

We use 100 watt yellow bug lights.

 

[sben763]

We use 100 watt yellow bug lights.

There is no need to work in yellow light. As long as the bulbs are 2 ft away florescent or incandescent they will not expose a screen.

I expose all my screens before washing them out. Some of the screens sit in the room with 4 bulb fluorescent fixture up to 2 hours and all washout just fine. I use to fumble around in yellow light till I did a little research on emulsion exposure and the strengths of UV light.

 

[chuckh]

Our exposure area is in the basement of our shop. Ceilings are less than 7' It helps if you stand between the floor joists! We have 6 bulbs around the room. Plenty of light, never a problem.

 

[jeron]

That will depend on the led some LEDs put off UV. I use 4ft standard fluorescents overhead. Although fluorescents put off UV they have a filter and at a few ft it would take days to expose the emulsion

Hey Sean, I know we talked about this in a different thread but now I have another question about your post here.

You mention they have a filter. Are you talking about the little tubes you can slide your fluorescents into before installing the bulb? After taking with you in the other thread I had the impression they were just strait up light with nothing covering them. I still think that is the case but just checking. I have yet to set some screens out to time how long it takes

 

[sben763]

Standard fluorescent lights contain their own filter within the bulb. I have no covers at all as I have a shop light that leaves the bulbs exposed. Very little UV light gets out unless the screen is right against the bulb cross lining can't occur because the light is not strong enough at 12" away.

Even daylight bulbs, full spectrum bulbs, plant bulbs or unfiltered black light bulbs at a few ft away can't expose emulsion(cross link) although with the above type of lights some skinning at the surface can occur if left out for 30+ min. If your fixture has a plastic cover over the bulbs it will further bock UV light.

I use photopolymer and can leave out screens in the shop with the lights on for days without any problems. I don't make it a habit but I do coat, line up films and washout all in standard white light from 4100k fluorescent bulbs. For 3-4 years I used yellow bug lights and even had a spot light above my film setting area. Its so much easier and quicker using standard white light.

 

[hbapparel]

I do the same. No dark room for me.

 

[jeron]

Sounds good to me...

Does anyone know if this is true.. I have read that emulsion only becomes light sensitive once it's dry..

Sent from my SGH-M919 using T-Shirt Forums

 

[sben763]

It is more light sensitive when dry. If you took a container of emulsion out in the sun it would change it properties. If you have exposed a screen you can wet with water and washout outside with out further cross linking.

 

[20vK]

Damp emulsion really doesn't form cross-links well. Even more so for photopolymer.

I'm sure if you left a tub if it out in the sun, it would mess it up, but in a printshop setting, humidity levels do need to be controlled in order to achieve effective exposure.

 

[20vK]

Ha ha! Guess Sean and I are on the same page!