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screen printing => Screen Making => Topic started by: bimmridder on November 12, 2015, 08:22:33 AM
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I failed. I am embarrassed to admit this. I try very hard to control my variables, instill systems...basically just do the best we can do. A few days ago I realized I have let something slip by that should never have happened. I have a nice size screen room where we coat, store, image and expose screens, I have ample lighting using 8 4' fluorescent fixtures with Encapsulite covers on them. So all is good, right? Not so much. I have not checked for the room being light safe. Why should I? Well the covers have obviously lost their ability to filter the "bad " light. I was having very random, I mean VERY random issues with developing. Of course I wanted to blame my pre-press guy for doing something wrong. When I did the same image that he couldn't completely wash out, it was fine for me. So what was he doing wrong?! Everything is standardized. Near perfect coating (for us), dead nuts on exposures....everything the same. Except the screen he grabbed was on the very top of the screen cart, that has no top cover, so it was exposed completely to the lights in the room. It was pre exposing. The screen I grabbed was a few screens down and hidden from the overhead lighting. It may have had a touch of pre exposure, but certainly not to the extent of the first one grabbed.
So I guess what I am saying is, because a bulb or filter says "Light Safe" or whatever it may say, doesn't mean it will be forever. And being yellow or red doesn't mean it is safe either. Fortunately we only wasted a few screens figuring out the problem, and soon enough that it wasn't hurting us too bad. (I was losing some half tones that shouldn't have been hard to hold)
So after I finished kicking myself in the ass, I figured out what lamps I want to use next, got them ordered, and have my electrician coming in to do some wiring updates. Even with the new set up, "Pre Imaging Exposure Testing" will become a monthly test, a new addition to my Pre Press System.
Do it right. Don't be a Dave
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So don't do it like I do? ;D
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Dave,
I think commendations are in order. Coming from my end of the spectrum I cannot begin to tell you the amount of calls we get of product blaming. There are those times when product can be blamed, but most of the time it is digging in understanding what is going on inside your four walls. Great job on trouble shooting and fixing the problem. All signs of a hands on leader !!!
Now brush yourself off and get back in the game Dave ..
Good Job
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Good job, easy fix- I still want to be a Dave. :)
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Now you got me thinking Dave.
However we keep all ours in covered boxes, and never in direct light for very long.
One cool thing we just did is put in motion sensor light switches, could save from unwanted extended/excessive light source, and saves on power consumption. It's also really cool walking into a room and the lights come on like Star Track.
Murphy37
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The Saati guys brought some REALLY cool glasses out the last time they were here.. you can 'see' UV light by looking at a light source and it glows a bright blue in the glasses.
awesome for finding light pollution sources.
I have no idea where to get them or how much they cost, but if they are cheap enough, might be something good to have in your kit. (I'll ask those guys where to get them and follow up)
-J
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Richard Greaves was here all day Monday, with the really cool glasses, and guess what? Same issues in our room. When you put the glasses on you can see it! 8)
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His glasses would be lit up like 4th of July in my shop. LOL
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Years ago, and old screenprint vet told me to leave a coated screen out with something opaque on top of it, wait an hour or two, and try to wash it out. If the whole goes down the drain, fine, but if you can see the area where the opaque object was, then you have a not totally light safe work area. We here don't have a totally light safe work area, opting instead for better overall lighting, we just don't leave anything out for very long. Coated screens in waiting are in cabinets, freshly coated and drying are in a drying cabinet.
Steve
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Why promote poor SOP?
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I know my little screen room is not light safe, but hey thanks now I got some work to do in there
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The Saati guys brought some REALLY cool glasses out the last time they were here.. you can 'see' UV light by looking at a light source and it glows a bright blue in the glasses.
awesome for finding light pollution sources.
I have no idea where to get them or how much they cost, but if they are cheap enough, might be something good to have in your kit. (I'll ask those guys where to get them and follow up)
-J
Those glasses expose more than you ever thought you'd see! (https://31.media.tumblr.com/ea48c25893f43334352fd0578add2cea/tumblr_mybtekkWrp1t0demio1_500.gif)
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They Live!
Murphy37
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We use the yellow tinted uv tubes and our strip doors to the screen room are the amber ones for welders but who knows? Thanks Dave now I'm paranoid. Going to check this out asap.
Brandt, for all the money and effort you are putting into your screen area with technology and those sweet custom cabinets, you might want to consider the basics of photo exposure. Not a knock on ya, just saying.
One of my favorite fight scenes....https://www.youtube.com/watch?v=c9rrgJXfLns (https://www.youtube.com/watch?v=c9rrgJXfLns)
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Brandt, for all the money and effort you are putting into your screen area with technology and those sweet custom cabinets, you might want to consider the basics of photo exposure. Not a knock on ya, just saying.
Screens spend such a small amount of time in the light here and we've played with it in dark room vs full open warehouse and we've notice no noticeable difference. So until it affects our situation for us we just have better things to spend money/time on right now. I'm sure someone with some fancy goggles and some equipment to measure everything to the nth degree will tell me how wrong I am. I don't doubt it for a second. It wont change for a second how we do things today though, we got plans and we will see them through.
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Why promote poor SOP?
A screen in our screen room could stay out for at least an hour, but essentially, they come out of a dark cabinet, have film attached, and are burned. Setting up an 8 color means burning two machine frames at a time, so none are out more than 10 minutes, way more than safe. We do not have a pre exposure issue, so our SOP is just that, works fine. Whatever works should be the SOP, until one changes...
Steve
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Even as bad as our set up is as far as doing it exactly right as far as screens go... our screens are only exposed to light for seconds while being coated, then whatever amount of time it takes the image to be loaded/printed and then set on the exposure unit. Its probably 2-3 minutes most screens to light thats 30ft in the air.
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Any skylights/open doors would be my concern. Before we had our exposure unit in the dark room
we would have photopolymer screens expose in the time it took to walk them from the dark room
to the vacuum frame, about ten seconds.
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light thats 30ft in the air.
That explains why it's working out. Diffuse light that far away is going to take a long time to start crosslinking into the emulsion layer even if you have the more spectrally rich (for emulsion curing purposes at least) high bay halide lights. Like ebscreen says, just watch out for any beams of sunlight cutting in somewhere.
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If anybody's interested, the glasses are available from Saati for $91.50. Part Number: SCVV121
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light thats 30ft in the air.
That explains why it's working out. Diffuse light that far away is going to take a long time to start crosslinking into the emulsion layer even if you have the more spectrally rich (for emulsion curing purposes at least) high bay halide lights. Like ebscreen says, just watch out for any beams of sunlight cutting in somewhere.
Exactly ;)
But we do have 2 large bay doors, 1 you could pull a semi truck and trailer in here easily, open all day. Heres a look at that, there is another one (smaller) to the right often open as well as 2 side doors. There is light in this joint.
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Any skylights/open doors would be my concern. Before we had our exposure unit in the dark room
we would have photopolymer screens expose in the time it took to walk them from the dark room
to the vacuum frame, about ten seconds.
Id be concerned too if I was using PP.
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So don't do it like I do? ;D
Not to stray off topic, but did you build those cabinets? I like that idea. Exactly what I had envisioned a while back. Just not sure how to keep the humidity down as I don't do near the screen volume you guys do.
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So don't do it like I do? ;D
Not to stray off topic, but did you build those cabinets? I like that idea. Exactly what I had envisioned a while back. Just not sure how to keep the humidity down as I don't do near the screen volume you guys do.
http://www.theshirtboard.com/index.php/topic,16253.msg155246.html#msg155246 (http://www.theshirtboard.com/index.php/topic,16253.msg155246.html#msg155246)
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So don't do it like I do? ;D
Not to stray off topic, but did you build those cabinets? I like that idea. Exactly what I had envisioned a while back. Just not sure how to keep the humidity down as I don't do near the screen volume you guys do.
Yes we had them built, cost me zero dollars and zero time as I cashed in some favors. Pretty nice, so far have really helped us as we didn't really have enough space for screens.