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screen printing => General Screen Printing => Topic started by: BartJY on June 25, 2019, 04:08:37 PM

Title: Which Safelight?
Post by: BartJY on June 25, 2019, 04:08:37 PM
Hi Folks,

I have Saati Textil PV emulsion, on the container is says to use yellow safe-lights when applying. I only have red safe-lights. Can I use those or do I need to buy yellow?

Thanks.
Bart
Title: Re: Which Safelight?
Post by: mk162 on June 25, 2019, 04:11:09 PM
red is fine, but you should look into yellow. so much easier on the eyes.

or just swap them to LED with a UV filter cover.  It's amazing to actually be able to see in the screen room.
Title: Re: Which Safelight?
Post by: BartJY on June 25, 2019, 05:19:04 PM
Will a yellow florescent work?

Thanks
Bart
Title: Re: Which Safelight?
Post by: Frog on June 25, 2019, 05:36:37 PM
It should, but read my answer in your darkroom thread.
Title: Re: Which Safelight?
Post by: Prince Art on June 26, 2019, 11:54:05 AM
Yellow "bug lights" work too, depending on what kind of fixtures you're working with.
Title: Re: Which Safelight?
Post by: RICK STEFANICK on June 26, 2019, 12:34:20 PM
red is fine, but you should look into yellow. so much easier on the eyes.

or just swap them to LED with a UV filter cover.  It's amazing to actually be able to see in the screen room.

and you can find the sleeves on amazon for like 5.00 each and be done with it.
Title: Re: Which Safelight?
Post by: jsheridan on June 26, 2019, 05:54:47 PM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.





Title: Re: Which Safelight?
Post by: BP on June 27, 2019, 07:24:56 AM
How does that work? Do you shut the lights when your not in the room??
Title: Re: Which Safelight?
Post by: jsheridan on June 27, 2019, 01:29:13 PM
No need to shut off the lights until we leave at night.

Old screens rest in front of coated screens as they lean against the wall to be imaged.



Title: Re: Which Safelight?
Post by: Frog on June 27, 2019, 01:35:57 PM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.

What's the situation for drying coated screens? A cabinet? The only piece of the puzzle not mentioned.
Title: Re: Which Safelight?
Post by: RICK STEFANICK on June 27, 2019, 04:33:01 PM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.

Amen!! Thanks John for the post. Its hard to believe people sitill coat in the dark. I know ya'll flip screens thru quick but would you agree the yellow tubes do add a level of safety for the shops that might have screens coated and store them for a few days or even a week?
Title: Re: Which Safelight?
Post by: jsheridan on June 28, 2019, 10:46:47 AM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.

What's the situation for drying coated screens? A cabinet? The only piece of the puzzle not mentioned.

In a room next to coating with a heater and a fan. Those bulbs are wrapped with an old piece of Rubylith. That is the only 'safe light' we use and I bet those bulbs were wrapped years ago.
Title: Re: Which Safelight?
Post by: jsheridan on June 28, 2019, 11:26:32 AM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.

Amen!! Thanks John for the post. Its hard to believe people sitill coat in the dark. I know ya'll flip screens thru quick but would you agree the yellow tubes do add a level of safety for the shops that might have screens coated and store them for a few days or even a week?

Yes they can add a level of safety if one so chooses to do so.
Title: Re: Which Safelight?
Post by: Sundaybest on July 10, 2019, 02:16:38 AM
I don't use any safelights or a darkroom. As long as you work fast and don't expose your screens to direct sunlight you will be good.
Title: Re: Which Safelight?
Post by: tonypep on July 20, 2019, 08:51:47 PM
That all depends on many factors. In one shop we used blue welders filters. Coated screens would last to upteen months.
Title: Re: Which Safelight?
Post by: Steve Harpold on July 21, 2019, 10:15:24 AM
Hey all,

Quick update on safe lights, in most cases it is a thing of the past.

Why?
Old style light bulbs (not that old for some on here) incandescent or florescent have our light in a very broad spectrum. Not exact but from around 300-700 NM. Emulsion is sensitive to light from 280-420 NM maybe a little higher. The light NM range that emulsion is sensitive to is not visible hence would make a poor choice for lighting applications.

Hence?
LED tubes, lights used for visible light application would not emit light in the 300-420 as it would be a waste of energy (it is not visible) so it is not necessary to use a filter to filter out wave lengths between 300-420 since there isn’t anything there anyway or such a small amount it is irrelevant.

When buying new LED tubes?
Look at the spectrum of light and make sure 300-420 NM is not present and you will be good to go
Title: Re: Which Safelight?
Post by: screenxpress on July 21, 2019, 03:57:05 PM
Don't need em anymore as we don't use Darkrooms.

Our screen room is a normal room with regular tube lights in the ceiling. We coat, store, image, burn and even washout screens in regular shop light conditions.

Thanks John.

I stopped using protective lighting years ago.  Obviously you can't leave dry screens out under the lights for storage, but coating, set-up for exposure, and washout under florescent bulbs has not been an issue.
Title: Re: Which Safelight?
Post by: Admiral on July 22, 2019, 11:57:25 AM
FYI our LED lights are GREAT at exposing emulsion.  They are 'non UV emitting' LED high bay lights but they sure do expose emulsion.  I tinted them with yellow film and the film itself degraded over less than a year from the UV the LEDs are in fact putting out.

I will be putting a stronger filter under them shortly in addition.  We don't get much UV scatter / exposure but enough to have to cover tops of screen racks. 

It is very bright in our dark room, we have 3 of these 500 watt bright LED lights in our dark room fyi.

Filters I got are from UVprocess.com, there are a few options there.  I also put the amber film on a large glass window between 2 rooms so we can see into the dark room too.
Title: Re: Which Safelight?
Post by: Zelko-4-EVA on July 22, 2019, 01:48:22 PM
we have the standard drop ceiling size 2x4 LED lights in our screenroom - i also used the UVprocess.com amber film.  i havent measured the UV output in our screen room but now its got me thinking...

Title: Re: Which Safelight?
Post by: Admiral on July 22, 2019, 01:52:12 PM
Correction - they are 100 watt VTac high bay UFO lights.  Still quite bright.  500 watt would be absurdly bright though.