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screen printing => General Screen Printing => Topic started by: Screened Gear on November 02, 2011, 03:08:47 PM
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I just bought new yellow bug lights for my dark room. I only had one light in there before and it was just too dark. It made it hard to clean out detail in the screen. (new dark room 2 months ago.) I put two yellow bug lights in there and now it is really bright. I am a little worried about the exposed screens in the room. I have a cabinet for my manual screens but I still need to build one for the auto screens. Should I be worried? I know a 60 watt white light would take...what 3 hours to expose a screen. I just want to make sure I don't have and issues.
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Did you buy fluorescent bug lights? I find the incandecents to be more harmful than just CFLs. I have yellow tubes over my lights and it's totally fine. I hang around in there sometimes just to get a tan.
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They are the incandescents. I had a CFL in there but it made the emulsion look black and hard so see thru. It was also about half as bright as the incondecents. The room is 10 x 12 with my washout booth, exposure unit, 1 screen cabinet, screen rack for the auto screens and registration unit for the MHM. Its nice and bright in there now I just want to make sure the screens just sitting in there are not getting exposed.
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get rid of the bug light.. seriously it's a joke..
Get yourself a 2 or 4 footer double bulb work light from home depot, T5 8 or 12 who cares.. it's like 30 bucks or something plugs into the wall and comes with chains and everything to hang from the ceiling or bolt it to the wall.
Then buy some CLEAR UV blocking light sleeves.. someone made a post here the other week and put a link in the post.. their like 5-8 bucks a sleeves.
**here you go.. link to thread. http://www.theshirtboard.com/index.php?topic=1826.0 (http://www.theshirtboard.com/index.php?topic=1826.0)
Put the light up, put on the sleeves and turn that baby on...
BAM!! hows that for seeing what the heck you're doing 8)
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get rid of the bug light.. seriously it's a joke..
Get yourself a 2 or 4 footer double bulb work light from home depot, T5 8 or 12 who cares.. it's like 30 bucks or something plugs into the wall and comes with chains and everything to hang from the ceiling or bolt it to the wall.
Then buy some CLEAR UV blocking light sleeves.. someone made a post here the other week and put a link in the post.. their like 5-8 bucks a sleeves.
Put the light up, put on the sleeves and turn that baby on...
BAM!! hows that for seeing what the heck you're doing 8)
I saw that post also. I think that would be perfect. I do like having the yellow light so I know its safe. But your right white light is a ton better.
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I've always used standard fluorescents, 8', with the yellow sleeves, no problems at all. I thought you meant a real dark room, like for photography. They need to be pretty dark, but who does that anymore?
Steve
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Hey, I knew I was good for something!
Be sure to read sweetts post on the second page (here's a link)
http://www.theshirtboard.com/index.php?topic=1826.msg19302#msg19302 (http://www.theshirtboard.com/index.php?topic=1826.msg19302#msg19302)
Those clear tubes still let some spectrum through... so I fear you will be going from bad to worse with your concerns. That said, he did say the AMBER sleeves were great.
Probably wouldn't be terrible to put some of the clear tubes in there and use them occasionally for inspecting screens you are washing out. I plan on putting these behind my washout booth... If the Amber isn't bright enough I might do two sets, one amber for basic operation and one white for when I'm reclaiming or for final inspection.
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Hey, I knew I was good for something!
Be sure to read sweetts post on the second page (here's a link)
[url]http://www.theshirtboard.com/index.php?topic=1826.msg19302#msg19302[/url] ([url]http://www.theshirtboard.com/index.php?topic=1826.msg19302#msg19302[/url])
Those clear tubes still let some spectrum through... so I fear you will be going from bad to worse with your concerns. That said, he did say the AMBER sleeves were great.
Probably wouldn't be terrible to put some of the clear tubes in there and use them occasionally for inspecting screens you are washing out. I plan on putting these behind my washout booth... If the Amber isn't bright enough I might do two sets, one amber for basic operation and one white for when I'm reclaiming or for final inspection.
Well after reading that it sounds like the clear sleeves are worthless. I am going to stick with my yellow bug lights for now. I read somewhere that the yellow is what blocks the UV. I even saw someone use Crylone Yellow spray paint to make white bulbs yellow and they worked just fine.
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They do make an amber sleeve. Still might give you more light and might be even safer (certainly cheaper in the long run).
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My coated screens are stored in a dark room. Just a few feet away is my exposure unit with a 60 watt light above. After exposure I walk with screens in hand, to the sink, through a room with indirect sun light coming through. Above the sink is another 60 watt bulb. I have never had any problems with these light sources messing with my screens.
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I use the fluorescent bug lights in my washout and my darkroom. Certainly bright enough to work by. Funny thing is, I wash out in the bathroom in my garage, and I always leave the window open unless it's really cold. I had a screen I'd exposed upside down, and set it to one side to reclaim later in the wash area. About two weeks later I need to reclaim it, so it hit it with some water before spraying with remover, and damned if the image didn't wash out after sitting there all that time. No direct sunlight, but filtered daylight and the bug light for hours at a time. This was with Ulano QX-1.
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I think light is way over rated..we coat in an open room under 4 foot fluorescents. lights and 15 feet from a 5 x 8 foot picture window that faces north.
we store screens in a cabinet that is light tight . After exposure we walk to wash out in the open room and past one window facing south, the window faces south I don't.
we don't take any special precautions except to avoid direct sun.
We use Ulano QXT .
We have never had a problem. I have even gone as far to place a soon to be exposed screen aside while I readjust the film on the exposure unit.
I have to say we have never had a problem really . QXT is known as ultra fast exposure so i really don't know what to say except we don't have any problerms and hold some raelly fine details.
mooseman
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When I worked out of my garage my pressure washed blew up so I had no water in my washout unit. I had a job that I had to get done so I just grabbed the screen and ran outside in a shaded spot to wash it out with the hose and I got nothing. It would not wash out anything. I could see the design for about 15 seconds then that even went away. I figured out if i took a spray bottle and wet the screen really good let it sit for about 30 seconds I could get outside and wash it out with out to much trouble. (so glad I don't have to do that again) I use Aquasol HV. Its great stuff but you have to have your times right. 25 seconds on my photo sharp exposure unit with 10% OEM.
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You can't just use regular ole clear sleeves, those are safety sleeves and they DO NOT block uv light.
they have to be rated for blocking UV light and the ones I've used, did not expose screens over time..
Better check those sleeves again and make sure they are the correct product.
http://www.uvprocess.com/product.asp?code=FILTER+++I (http://www.uvprocess.com/product.asp?code=FILTER+++I)
Using the above with a standard fluorescent bulb that emits under the 300nm range.. not a speck of UV llight will get past the clear sleeve.
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I use the incandescent bug light. No problems. Easy.
During setup, I'll have the emulsion/cap inches away from the 60w yellow bug light for half hour or more with no issues.
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I was told by a Ulano tech that the clear sleeves even up to 400nm UV protection are not good enough, so I went with the amber sleeves which block more like 525nm per Ulano's recommendation, not much price difference between them, and I don't mind working in the yellow light.
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Ah, the old bug light story, eh? It's been over 4 years since I had a bug light in operation.
My suggestion is just coat your screens under florescent light and let dry in the dark like a drying cabinet or a covered screen rack. When it's time to prepare one, just pull out a screen under normal room lighting, tape on the film and expose.
The only story I ever heard of room lighting exposing was turning on the light behind a washout sink before wetting the screen had a negative effect. Mine are florescent behind my washout sink so must have been some robust suckers.
I work under normal room (florescent) light and stay away from old man sun. You can't run fast enough to shade to stop the sun from exposing. Well maybe if you were Superman. :)
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Ah, the old bug light story, eh? It's been over 4 years since I had a bug light in operation.
My suggestion is just coat your screens under florescent light and let dry in the dark like a drying cabinet or a covered screen rack. When it's time to prepare one, just pull out a screen under normal room lighting, tape on the film and expose.
The only story I ever heard of room lighting exposing was turning on the light behind a washout sink before wetting the screen had a negative effect. Mine are florescent behind my washout sink so must have been some robust suckers.
I work under normal room (florescent) light and stay away from old man sun. You can't run fast enough to shade to stop the sun from exposing. Well maybe if you were Superman. :)
Even easier. I wonder if all products behave the same under florescent light?
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I use both lights florescent lights and the yellow bug lights not at the same time though in my dark room, never had any problems with the screen being preexposed, then I wash then out under full florescent shop lights heck I,ve even left one in the washout for about 15 mintues and finished it up with no problem just a little harder rinse.
Darryl
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Look at it this way, they say you need a metal halide light to properly expose screens. Not a High Pressure Sodium bulb. Which both are used in growing plants and taking care of animals that need UV spectrum light.
So if that isn't enough UV then "non-UV" lights certainly shouldn't be "enough".
Now... the problem is... what is "enough".
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The only story I ever heard of room lighting exposing was turning on the light behind a washout sink before wetting the screen had a negative effect.
Uhh, I think that was me, Wayne. I was using Saati's TextilPV, which I thought was the best plastisol emulsion I'd tried, especially for the price compared to QTX.
Anyway, I deduced that the backlight was the issue, since that was the only time I'd ever done that, and the only time I've ever had an issue washing out a stencil. I can't say the bulb was particularly potent, but it might very well be the emulsion was that fast. Currently I carry coated screens, wet or dry, through my garage with 4 sets of fluorescent shop lights and a window and a door open and have no trouble. I do use a bug light in my exposure room and when I'm washing out, but a light-tight room with a 15w red darkroom light of the variety used with ortho film is way overkill. I've read of folks using regular fluorescents in an exposure unit so I guess there must be a little UV light coming out, but I think unless you're holding a screen close to a bulb, exposure is pretty unlikely. No one seems to really have any trouble with ceiling-mounted fixtures.
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10 x 16 room for exposure unit (and spare), washout sink, screen dryer and a table. Inside painted black with 3 red lights on the ceiling and two more over the washout sink - regular flourescents overhead are on separate switch from the reds. Also a red light over the dark room door to keep people from running in and out when we have film out.
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I work from my basement, and I do not have separate dark room.
I work in printing company and when we got rid of our dark room (went direct to plate) we hat plenty of UV safe bulbs left.
Of course, some of those ended up in my possession :) Now in my basement, I had the basement window blocked to prevent light from coming in, I turn off regular lights and I turn on fixture with 2 UV safe tubes and also I have 2 bug repel bulbs that I have over the press and in front of the washout booth.
When the screen is washed out, I have the backlight turned off until I'm almost done washing the screen. Then, I turn on the backlight and I do the final and fine detail with the light turned on.
A lot of turning on and off in my basement :)
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When I worked out of my garage my pressure washed blew up so I had no water in my washout unit. I had a job that I had to get done so I just grabbed the screen and ran outside in a shaded spot to wash it out with the hose and I got nothing. It would not wash out anything. I could see the design for about 15 seconds then that even went away. I figured out if i took a spray bottle and wet the screen really good let it sit for about 30 seconds I could get outside and wash it out with out to much trouble. (so glad I don't have to do that again) I use Aquasol HV. Its great stuff but you have to have your times right. 25 seconds on my photo sharp exposure unit with 10% OEM.
I use Aquasol HV and had a similar experience. It was a morning when the sunlight was casting a direct vertical stream of light in my washout booth that hit a screen I was washing. It left me with a hardened vertical stripe through the whole design. Needless to say with Aquasol I avoid direct sunlight like a vampire. That being said, I align my film to my fpu out in the shop, grab a screen from the dark room, stick it and walk to the exposure unit in regular shop fluorescent light, then to the backlit washout booth and wash out and never had any issues. I also gang designs on screens so I align one film, stick it, remove the screen and lean it against my leg while I position and tape the other film, stick that one, then expose.
I don't have any lights in my dark room, I coat screens just outside the door on the floor then rack them. I use ambient shop light to pick the right mesh while I'm in there with the door open.
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My "dark" room is actually pretty damn bright. Four 15w CFLs in it.
Of course, I'm not trying to burn 3% 65lpi dots either, so a little light pollution doesn't hurt me a bit.