# Screens won't burn anymore



## Yasirm86 (Jan 22, 2012)

ok major problem...i mean MAJOR! ok so lately past few weeks to 1 month I have this issue with burning screens I don't know what it is, but I havent changed anything at all same emulsion, same time on the exposure unit. So i have attatched pics to show you guys whats going on. Sometimes the screens will come out and sometimes it won't. Its like the top half opf my screen won't show or the side of the screen..it is so weird. Today I have had to waste almost 4-5 screens because of the same issue. the image was coming out but it wasnt washing out, and on one screen on one side the image was showing and tghe other side it was very light to where it wouldn't show on the screen. I am so behind in work right now trying to figure out what is going on. I used the pressure washer and all it does it blow the image out. Can somebody please tell me what could be the problem, I really am stuck right now. I feel like the top half of the screens wont expose....I don't know i am so confused. PLEASE HELP!


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## Dakent012 (Nov 7, 2012)

What do you do for each step of the life cycle of the screen? What emulsion do you use? Have you used an exposure calculator?


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## Dakent012 (Nov 7, 2012)

Anyway you could post any more pictures of close ups of problem areas?


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## Yasirm86 (Jan 22, 2012)

Dakent012 said:


> What do you do for each step of the life cycle of the screen? What emulsion do you use? Have you used an exposure calculator?


Life of the screen meaning?? And I use mirakimi HV emulsion...no I haven't, but I've never had a problem like this until recently. 2.5 years of printing.


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## nypdofficer1 (Feb 19, 2012)

Are you degreasing your screens?


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## Dakent012 (Nov 7, 2012)

I was asking what you do specifically for each step of the screen process, how do you complete the reclaiming procedure, coating, burning, washing out etc.


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## Yasirm86 (Jan 22, 2012)

Dakent012 said:


> Anyway you could post any more pictures of close ups of problem areas?


The biggest problem is that when I go to wash the image out it either shows up light or half of the image shows so I can wash it and it takes very long to wash out.


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## Yasirm86 (Jan 22, 2012)

nypdofficer1 said:


> Are you degreasing your screens?


Not all the time, but yes I am. Did degrease on my last run and screens still was having trouble washing out. Last night for example had an image about 10 inches wide when I burned it and sprayed it with the hose it would show, but you can tell that it was very lightly showing so when I sprayed it with the hose it wouldn't come off like it did before....I used a pressure washer and the image broke apart so I burned another screen. This time same thing, but when I used the pressure washer it was so hard for the image to come out took almost 5 minutes and of me adding a lot of up close pressure towards the screen. Image finally came out.


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## Yasirm86 (Jan 22, 2012)

Dakent012 said:


> I was asking what you do specifically for each step of the screen process, how do you complete the reclaiming procedure, coating, burning, washing out etc.


Emulsion, haze remover, degrease, sit dry, flood screen, dry, burn. Washout process: spray in dark room let sit for 1 min, spray again, let sit for one minute. Turn on the lights then continue to spray. I do all of this with the hose on shower. Has always worked never had an issue. Lately I've had to use the hose on jet to push the image out.


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## jimcr (Feb 3, 2009)

did anything change , water temp, age of emulsion, new emulsion, exposure time, type of degreaser, is it a photo polymer or deizo ,different haze remover, how old are your bulbs in the exposure unit?
Can you post better photos that are clear enough to see?


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## Yasirm86 (Jan 22, 2012)

jimcr said:


> did anything change , water temp, age of emulsion, new emulsion, exposure time, type of degreaser, is it a photo polymer or deizo ,different haze remover, how old are your bulbs in the exposure unit?
> Can you post better photos that are clear enough to see?


Everything is the same nothing has changed and the bulbs I'm not sure never changed them. It's like a hit and miss one day everything will be fine next Nothing blows out. My camera on my phone sucks so that was the best I could do with the pics.


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## 20vK (Jul 9, 2011)

Buy fresh emulsion, fresh bulb for your exposure unit, check humidity is not off the scale.

I bought a new bulb and went from 12 minutes to 3


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Buy fresh emulsion, fresh bulb for your exposure unit, check humidity is not off the scale.
> 
> I bought a new bulb and went from 12 minutes to 3


How do I check the humidity? And also I only burn screens for about 2-3 minutes.


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## 20vK (Jul 9, 2011)

Buy a hydrogometer. Mine was $12. It's how you check your screens are dry.

It's not the time, it's the relative time.

If you used to burn for 2-3 minutes, then maybe that's not enough anymore. Bulbs can output less light as they age.

I would do an exposure test / stouffer strip and dial in my times again. EIther that, or eliminate all the variables - old emulsion & old bulb


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## sben763 (May 17, 2009)

Also if your in a cold environment and using unfiltered blacklights you may need to prewarm your bulbs. If they are dim and appear to be dancing then they are not coming up to full power. If they are over a year old maybe just time to replace.

I bought a weather station with a remote sensor I put that in my dry box to check humidity and temp while drying. Was about $20 and can buy additional remotes sensors for a total of 3. I just ordered 2 more 1 for storage box and 1 for out doers for a total of 4 locations.


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## jimcr (Feb 3, 2009)

As Sean and I are in the same general part of the mid west , things have got colder here and especially if you print in you garage the temps have changed, the temps the last few nights here have been in the 20's , cold emulsion , air temp , and humidity can all affect the way things dry. If you are putting a thick coat of emulsion down it might not be full dry on the screen .


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Buy fresh emulsion, fresh bulb for your exposure unit, check humidity is not off the scale.
> 
> I bought a new bulb and went from 12 minutes to 3


And this is a brand new gallon of emulsion.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Also if your in a cold environment and using unfiltered blacklights you may need to prewarm your bulbs. If they are dim and appear to be dancing then they are not coming up to full power. If they are over a year old maybe just time to replace.
> 
> I bought a weather station with a remote sensor I put that in my dry box to check humidity and temp while drying. Was about $20 and can buy additional remotes sensors for a total of 3. I just ordered 2 more 1 for storage box and 1 for out doers for a total of 4 locations.


Unfiltered black lights as in white coating?? They don't seem to be going out and I'm sure they're not as bright as they once were. So the sensor would go in the box and it checks temp?


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## sben763 (May 17, 2009)

Temps and humidity. I take a picture later when it warms up. I am still without power in the shop and last night was getting dangerously cold for the ink and chemicals. I still only have a small generator to run furnace, well and electronics on tankless water heater. Funny how the cable company takes better care of restoring then our CO-OP electric company. I am the only one on my sub station with no power. They have a update on their Website and it only show 1.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Also if your in a cold environment and using unfiltered blacklights you may need to prewarm your bulbs. If they are dim and appear to be dancing then they are not coming up to full power. If they are over a year old maybe just time to replace.
> 
> I bought a weather station with a remote sensor I put that in my dry box to check humidity and temp while drying. Was about $20 and can buy additional remotes sensors for a total of 3. I just ordered 2 more 1 for storage box and 1 for out doers for a total of 4 locations.


How long do I prewarm bulbs for? And do you thill I should burn longer?


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## sben763 (May 17, 2009)

Just like 5 min to pre warm. I had to do this in the winter with my black light unit. I now have a point light source metal halide so I have to pre warm 10 min all the time now but worth the hassle. 

It better to pre warm then to try and just add time as it would be just a guess.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Just like 5 min to pre warm. I had to do this in the winter with my black light unit. I now have a point light source metal halide so I have to pre warm 10 min all the time now but worth the hassle.
> 
> It better to pre warm then to try and just add time as it would be just a guess.


Ok cool I will try it in a bit and let you know the results...thank you


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Just like 5 min to pre warm. I had to do this in the winter with my black light unit. I now have a point light source metal halide so I have to pre warm 10 min all the time now but worth the hassle.
> 
> It better to pre warm then to try and just add time as it would be just a guess.


ok so it worked yesterday and today same thing, its like half of the screen burned and half didnt. Back to square 1.


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## Yasirm86 (Jan 22, 2012)

jimcr said:


> As Sean and I are in the same general part of the mid west , things have got colder here and especially if you print in you garage the temps have changed, the temps the last few nights here have been in the 20's , cold emulsion , air temp , and humidity can all affect the way things dry. If you are putting a thick coat of emulsion down it might not be full dry on the screen .


I am flooding front and back of the screens. Yesterday it worked fine today back to the same thing its like the bottom half came out and the top half didnt.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Buy a hydrogometer. Mine was $12. It's how you check your screens are dry.
> 
> It's not the time, it's the relative time.
> 
> ...


what do i do with the hydrogometer??


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## jimcr (Feb 3, 2009)

you say you are flooding the screen ? are you coating 1/1 or 2/1 , are you using the sharp side or round side of the scoop coater. Did the problem start with the new emulsion?
You would put the Hygrometer right next to where you dry your screens , it will tell you the amount of moisture in the air. It measures relative humidity in the air. If you dry in a box put it in there.


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## Yasirm86 (Jan 22, 2012)

jimcr said:


> you say you are flooding the screen ? are you coating 1/1 or 2/1 , are you using the sharp side or round side of the scoop coater. Did the problem start with the new emulsion?
> You would put the Hygrometer right next to where you dry your screens , it will tell you the amount of moisture in the air. It measures relative humidity in the air. If you dry in a box put it in there.


Ok so I flood 1/1 or just front side. Using the sharp side of the coated and no it didn't start with the new emulsion it's been doing it for about 2 months now on and off. What would I look for if I put the hygrometer in the box??


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## sben763 (May 17, 2009)

Are you verifying the lamp is lighting. I ve seen where a lamp will only light some of the time. Or it may be time for new bulbs if you humidity is low. You should be 45% or lower before exposing bug I get a min of 40% before exposure.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Are you verifying the lamp is lighting. I ve seen where a lamp will only light some of the time. Or it may be time for new bulbs if you humidity is low. You should be 45% or lower before exposing bug I get a min of 40% before exposure.


Can I get blacklight bulbs with the blue coating or flourscent bulbs? Or do they have to be blacklight bulbs with cleaR coating


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## sben763 (May 17, 2009)

Unfiltered black lights will give best results. There is some GE bulge that work well and the ones from Ryonet work well.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Unfiltered black lights will give best results. There is some GE bulge that work well and the ones from Ryonet work well.


Unfiltered black lights? I'm at lowes right trying to get some they have the purple coating and the flourscent


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Unfiltered black lights will give best results. There is some GE bulge that work well and the ones from Ryonet work well.


what kind of ge bulbs? any stores that I can get them from?? and also what else can I do? I need these shirts done by saturday and im in a bind. step wedge test? i bought the thermometer as well


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Are you verifying the lamp is lighting. I ve seen where a lamp will only light some of the time. Or it may be time for new bulbs if you humidity is low. You should be 45% or lower before exposing bug I get a min of 40% before exposure.


Can you explain this to me a bit more?? I bought a thermometer I'm going to put it inside the box how should the temp be inside?


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## sben763 (May 17, 2009)

You really need to buy a small weathered station. So you know the humidity and want it less then 45% and the temp never over 95 while drying. If you are in the US you can get at a Walmart, Menards, Lowes, Home Depot, Kmart ect. Unfiltered blacklights aren't sold in these stores but a few options. In fluorescents a few options are Daylight bulbs or plant growth bulb they will require longer times but will work. The day light will be longer then the plant growth bulbs.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> You really need to buy a small weathered station. So you know the humidity and want it less then 45% and the temp never over 95 while drying. If you are in the US you can get at a Walmart, Menards, Lowes, Home Depot, Kmart ect. Unfiltered blacklights aren't sold in these stores but a few options. In fluorescents a few options are Daylight bulbs or plant growth bulb they will require longer times but will work. The day light will be longer then the plant growth bulbs.


I went to lowes to buy one and they had no idea what I was talking about. The guy gave me a weather thermometer


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## sben763 (May 17, 2009)

As long as it has humidity that's what counts. I bought mine at Menards and they were calked weather station. I guess that's what minimum wage get you.

Something like this. http://www.acurite.com/13230-deluxe-weather-station.html?gclid=CJGH8qis-boCFepFMgodaEEAgQ


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## tpitman (Jul 30, 2007)

Just out of curiosity, how are you handling your screens after exposure? Where are you washing them out? What's the lighting situation? Any chance that there's some light leaks getting at your screens before exposure, or after exposure before washout? Murakami HV is pretty fast, so if you've got a situation where there's an opportunity for the emulsion to get some unwanted exposure, that might explain your issue. It just seems odd that sometimes it works and sometimes it doesn't.


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## sben763 (May 17, 2009)

Good point to but so does humidity especially with photopolymer and SBQ emulsions.


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## 20vK (Jul 9, 2011)

I see huge moisture absorption on unexposed but dried photopolymer here - it got to the point where the emulsion would not expose and just washed off. Even after extra exposure time. A dehumidifier and hydrogemeter changed everything


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## sben763 (May 17, 2009)

I just recently had the same. My dehumidifier was old and doesn't have a freeze up switch in cooler temps it doesn't work well. I recently went to a point light source and everything was just washing out after having success at 1:30 and using a exposure calculator. I burnt a screen for 6:00 and it still washed out. Went to Menards and got the weather station and humidity was 76% in shop and 68% in dry box. Broke down bought a new dehumidifier got shop to 45% and dry box is 35% and my times are now below 1:00 except on thick stencils.


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## porkchopharry (Mar 4, 2012)

I've had this issue before and it boiled down to the fact that either my Textil PV was bad from the distributor, or I accidentally exposed it in the bucket. I'm usually real careful though. They replaced it and I never had the issue again. YMMV.


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## Yasirm86 (Jan 22, 2012)

tpitman said:


> Just out of curiosity, how are you handling your screens after exposure? Where are you washing them out? What's the lighting situation? Any chance that there's some light leaks getting at your screens before exposure, or after exposure before washout? Murakami HV is pretty fast, so if you've got a situation where there's an opportunity for the emulsion to get some unwanted exposure, that might explain your issue. It just seems odd that sometimes it works and sometimes it doesn't.


very weird like today for example out of about 9 screens 4 didnt wash out. the ones didnt wash out the image wasnt even showing enough through the screen you could tell it wasnt going to wash out. Do you think I need new bulbs? and im in the garage with the lights off and have a yellow light on thats it.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> As long as it has humidity that's what counts. I bought mine at Menards and they were calked weather station. I guess that's what minimum wage get you.
> 
> Something like this. AcuRite 8" Digital Weather Station with Forecast / Temperature / Humidity / Pressure / Clock / Moon Phase 13230


lol so with the humidifier what do I do?? put it in my box with the screens???


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## sben763 (May 17, 2009)

The dehumidifier some cut out a section and blow the dehumidifier air into the dry box. I personally just have it in my shop near the dry box.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> The dehumidifier some cut out a section and blow the dehumidifier air into the dry box. I personally just have it in my shop near the dry box.


I used a fan for a while. What about that thermometer one? To check the humidity


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## sben763 (May 17, 2009)

Yes put the remote sensor in the box. That way you know the temp and humidity in the box.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> Yes put the remote sensor in the box. That way you know the temp and humidity in the box.


Ok so I did that and when I left it...it was at 45 humidity and 67 degrees inside I believe


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## sben763 (May 17, 2009)

I get the humidity under 40% befor exposure. I also keep the temp under 95F


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> I get the humidity under 40% befor exposure. I also keep the temp under 95F


How do I do that??


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## 20vK (Jul 9, 2011)

A dehumidifier will deal with the humidity.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> A dehumidifier will deal with the humidity.


Ok it went up to 56 degrees but the temp was low. And I can get the small ones? How much do they range?


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## 20vK (Jul 9, 2011)

They are rated on capacity. In the US it's how many pints. Mine is a 50 pint per day model and had a fan blowing air up. The fan keeps the air moving, which help drying too. You can see my hydrogometer on the top screen

In my dry rack box, I would have been happier to go for a much smaller model. It can get quite warm with the lid shut. I've seen temps of 100 F, so I normally leave the door slightly ajar to keep the heat below 95


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## Yasirm86 (Jan 22, 2012)

20vK said:


> They are rated on capacity. In the US it's how many pints. Mine is a 50 pint per day model and had a fan blowing air up. The fan keeps the air moving, which help drying too. You can see my hydrogometer on the top screen
> 
> In my dry rack box, I would have been happier to go for a much smaller model. It can get quite warm with the lid shut. I've seen temps of 100 F, so I normally leave the door slightly ajar to keep the heat below 95


I have a fan as well as the hydrogometer setup now. One day it was fine today again screens wouldn't wash off. The image wouldn't even come off it's like it's over exposed so i lowered the time by 30 same thing.


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## ukracer (Feb 11, 2010)

Yasirm86 said:


> I have a fan as well as the hydrogometer setup now. One day it was fine today again screens wouldn't wash off. The image wouldn't even come off it's like it's over exposed so i lowered the time by 30 same thing.


Forgive me for poking my nose in something I know nothing about BUT I saw you say it was a new gallon of emulsion. Another guy said he had similar problems and they replaced the emulsion. (whatever the reason was) can you get some new emulsion to try??

Regards Andy T


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## Yasirm86 (Jan 22, 2012)

ukracer said:


> Forgive me for poking my nose in something I know nothing about BUT I saw you say it was a new gallon of emulsion. Another guy said he had similar problems and they replaced the emulsion. (whatever the reason was) can you get some new emulsion to try??
> 
> Regards Andy T


Do you think that it is the emulsion?? I'm so behind in work that it's killing me lol. I don't know what it is at all I've tried everything


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## 20vK (Jul 9, 2011)

I doubt it is your emulsion, as you already said sometimes it works and sometimes it doesn't.

You just said your humidity went up to over 50 and the screens didn't expose? If the air is wet, your emulsion is never going to dry then is it? That's like trying to dry your pants by putting them in the sea. Wet emulsion will not expose properly or form the cross links necessary for successful exposure. Have you tried dropping the humidity to under 40 yet and then exposing?


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## Yasirm86 (Jan 22, 2012)

20vK said:


> I doubt it is your emulsion, as you already said sometimes it works and sometimes it doesn't.
> 
> You just said your humidity went up to over 50 and the screens didn't expose? If the air is wet, your emulsion is never going to dry then is it? That's like trying to dry your pants by putting them in the sea. Wet emulsion will not expose properly or form the cross links necessary for successful exposure. Have you tried dropping the humidity to under 40 yet and then exposing?


When I grab the screens again they're completely dry. Not wet I know how the wet emulsion and not fully dried screens are, but these are dry. I have a fan there as well. How do I drop the humidity? With the dehumidifier??


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## 20vK (Jul 9, 2011)

Yes - with a dehumidifier.

You can't tell by feeling them if they are wet or dry.

If your humidity in your room is 56% relative humidity, then your screens are only 56% dry. ie, not dry!


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Yes - with a dehumidifier.
> 
> You can't tell by feeling them if they are wet or dry.
> 
> If your humidity in your room is 56% relative humidity, then your screens are only 56% dry. ie, not dry!


I have it in the box and it says 56% so they haven't been drying? It bounces around it goes from 40% -44 now it was just at 50% I would need it below 45?


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## 20vK (Jul 9, 2011)

Yes - if you are at 56%, that is as dry as the screen will get. Any reduction has to be for a sustained period to allow the air to slowly suck the moisture out the emulsion.

I run my drier before I expose any screens for upto an hour. In the dry box, that's enough. in a room, you may need to run it longer.
Photopolymer is particularly sensitive to humidity during exposure AND also absorbs moisture in the air quicker than diazo, so I always dry my screens and get the room or box they are in down to the low 40's

This may be why suddenly your emulsion stopped working and you got sporadic results. We get high humidity in the summer here - but I'm in the Caribbean. This summer, my emulsion just stopped exposing and started to just wash out. Dehumidifier sorted all that out.

Best thing is: dry your room or dry box until it wont dry any more. Coat your screens. Watch humidity rise. Then wait for it to drop back down to the original dry level.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Yes - with a dehumidifier.
> 
> You can't tell by feeling them if they are wet or dry.
> 
> If your humidity in your room is 56% relative humidity, then your screens are only 56% dry. ie, not dry!


Ok so it's 58 indoor humidity. 55 indoor temp. And 43 outdoor temperature


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Yes - if you are at 56%, that is as dry as the screen will get. Any reduction has to be for a sustained period to allow the air to slowly suck the moisture out the emulsion.
> 
> I run my drier before I expose any screens for upto an hour. In the dry box, that's enough. in a room, you may need to run it longer.
> Photopolymer is particularly sensitive to humidity during exposure AND also absorbs moisture in the air quicker than diazo, so I always dry my screens and get the room or box they are in down to the low 40's
> ...


Run a drier? I'm in the garage I have no drier here my screens are coated now I'm going to go get a dehumidifier now then what do I do??


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## 20vK (Jul 9, 2011)

Yasirm86 said:


> Ok so it's 58 indoor humidity. 55 indoor temp. And 43 outdoor temperature


Your screens are wet, then. At around 60, I got no exposure. Your temperatures are cool, so that helps.


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## 20vK (Jul 9, 2011)

A dehumidifier IS a drier. It dries the air.


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## 20vK (Jul 9, 2011)

Plug in the dehumidifier, turn it onto the driest setting and watch your humidity in the room drop.

Maybe get a good book to read while this happens.

See how long it takes for the humidity to drop by 5. Then you can predict how long it may take to drop it to around 40.


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## 20vK (Jul 9, 2011)

Make sure you buy a dehumidifier.

A humidifier will do the opposite and you'll never ever screen print.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Make sure you buy a dehumidifier.
> 
> A humidifier will do the opposite and you'll never ever screen print.


Ok I'm at wal mart and all they have are humidifiers. Who carries dehumidifiers??


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## 20vK (Jul 9, 2011)

Yasirm86 said:


> Ok I'm at wal mart and all they have are humidifiers. Who carries dehumidifiers??


Ask them. I bet they do - they may be in a different section to the humidifiers

Dehumidifiers - Walmart.com


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Ask them. I bet they do - they may be in a different section to the humidifiers
> 
> Dehumidifiers - Walmart.com


Lol I asked these guys know nothing they show me the humidifiers and the air purifiers


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## 20vK (Jul 9, 2011)

Maybe under home improvement? That's the section on the website. Mine were near the fans at my store (not Walmart). Is there an air conditioning section? Maybe near that.

Ask them to type in Frigidaire or dehumidifier into their computer - they must be able to find out what department it is in.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Maybe under home improvement? That's the section on the website. Mine were near the fans at my store (not Walmart). Is there an air conditioning section? Maybe near that.
> 
> Ask them to type in Frigidaire or dehumidifier into their computer - they must be able to find out what department it is in.


Nowhere to be found looked everywhere. I'll go to lowes or Home Depot tomorrow. So can I place the dehumidifier in the box, next to the box? Or it has to go where? And how long should it take to drop the humidity would you say?


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## 20vK (Jul 9, 2011)

Either the room, but ideally the dry box - it has a smaller volume so will dry quicker, won't it.

Watch out for temperature though - you have a mechanical process that generates heat. Make sure it doesn't rise above 95 Fahrenheit.

You can also buy online at the link I posted.


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## 20vK (Jul 9, 2011)

As for how long it takes, I told you earlier to check how long it takes to drop 5%, then you can calculate from there. The smaller the volume of air, the less it will take.

I have no idea how big your room or dry box is, the size of your screens, how many screens you fit in there or what the capacity is of the dehumidifier you have not yet bought.

I normally give an hour to dry screens in my drybox and 50 pint unit. But my circumstances are not the same as yours. My temperature is more than double yours, for example.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> As for how long it takes, I told you earlier to check how long it takes to drop 5%, then you can calculate from there. The smaller the volume of air, the less it will take.
> 
> I have no idea how big your room or dry box is, the size of your screens, how many screens you fit in there or what the capacity is of the dehumidifier you have not yet bought.
> 
> I normally give an hour to dry screens in my drybox and 50 pint unit. But my circumstances are not the same as yours. My temperature is more than double yours, for example.


I usually I dry my screens overnight...do you run the dehumidifier all night?


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## 20vK (Jul 9, 2011)

No. I run it for an hour.

You need to run your own tests.

You should read back through this thread - all the info you need is there.

The dehumidifier is sucking moisture out the air and drying it. Before, you were trying to dry your screens in wet air.

Get your dehumidifier, turn it on. look at your watch. When the air is dry, look at the time again. The elapsed time is how long you need to dry screens for and how long you need to run the dehumidifier for.

On wetter days or more screens, it will take longer, as there is more moisture in the air. Run more tests. Take notes so you don't forget.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> No. I run it for an hour.
> 
> You need to run your own tests.
> 
> ...


Ok so pretty much run the dehumidifier till it reaches around 40% time it. Then that's how long I always will need to dry my screens for right? Abd I'll place this by my box. I'll do this tomorrow and see how it goes. Will report back with results. One question: let's say it takes one hour to dry get the humidity down to 40% or so. I turn the dehumidifier off abd I can let the screens sit in the box till I burn them?


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## 20vK (Jul 9, 2011)

No. it is not always the same. ^^ I just said it wasn't and depends on variables.

Depends if the humidity rises in the box again, doesn't it? I don't know what your box looks like or how good the seal is or how big your room is. But if you take your dry pants and put them back into the wet ocean, they'll get wet again. 

The best thing is to look at the hydrogometer reading inside the box and see if it rises significantly. If it does, then you'll either need to run the dehumidifier again or keep it going. 

Slow down, read the advice on this thread and absorb it. Use the search function to educate yourself about this. I learned everything I told you by reading about humidity on this forum, so the info is definitely here.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> No. it is not always the same. ^^ I just said it wasn't and depends on variables.
> 
> Depends if the humidity rises in the box again, doesn't it? I don't know what your box looks like or how good the seal is or how big your room is. But if you take your dry pants and put them back into the wet ocean, they'll get wet again.
> 
> ...


Ok so I get everything you're saying I'm just confused on a few things I read everything again as well. Ok so I had the sensor to the weathered station put outside not in the box so I just moved it. Also the dehumidifier I understand humidity rises and temp up and down so I would need to base it off of that...so what I'm reading is that the dehumidifier makes the screens dry faster. Let's say I run it and brings the temp humidity down to 40% right and I don't burn my screens till morning and turn the dehumidifier off I check again and it's gone back I will need to run it again right? The weathered station screen is In the box with the sensor is that how it is or shall I remove the screen? Lol I know it's a lot of questions just confused I've been doing this for over 3 years now and have never ran into this issue before ever. That's why I'm so confused I've been doing everything the same.


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## 343paul (Jan 1, 2012)

Exposure calculator to determine exposure time. Your time under bulb exposure (TUBE) is consistently changing because of emulsion age and bulb uv output reduction. Drying emulsion for 2 hours in sub 50% humidity with airflow is critical for proper emulsion cross linking during exposure. These are the 2 most frequent problem areas in the stencil process.


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## ukracer (Feb 11, 2010)

Yasirm86 said:


> That's why I'm so confused I've been doing everything the same.


Thats also confusing me.  BUT let me make it clear I DONT screen print . My comment about the emulsion was purely that reading the thread you seem to have been ok for 3 years and them BOOM you then get problems. I thought grabbing a new tin of emulsion would remove a variable that COULD be a one off.

I bow to the guys who screen print when they say it wont be emulsion as it works sometimes but does not others for you.

I also take account of the comment made that said. " Your time under bulb exposure (TUBE) is consistently changing because of emulsion age and bulb uv output reduction."

SO as a lay person trying to look at what may be obvious but missed I am not sure you fully understandthe relationship between the 2 things above.

As for the Dehumidifier you do know that they contain a container that collects water taken out of the air by the unit?? SO if you run it and you humidity levels drop. BUT when you stop it the humidity levels start rising then you will need to run it while you are drying.

I used to run a dehumidifier 24 hours as my back room has a polycarbonate rook and excess moisture (water actually ran down the walls) dripped from the roof down the walls in the winter.

This was not for printing , mine was just a tool to keep my house dry and the dampness away.


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## sben763 (May 17, 2009)

First if its working sometimes and not others then its not the emulsion. Something is changing. Is it possible that you have always had the humidity issue. See info below

Moist emulsion will not be as sensitive as dry causing you to expose longer. If you are under exposed your screen will blow out, this includes if your emulsion is moist. 

If your over exposed you will have problems washing out, this includes too much exposure time, improper films, or pre or post exposure. 

Tape a piece of cardboard or a dime to your next screen. If it washes out where the dime is but where your film doesn't your either over exposing or have film problems. To determine which if the dime has a defined edge with the ridges or a round edge that is about the same size as the dime then its your film. If you edge has a very irregular edge and is smaller then the dime you overexposed. It would be best to examine with a loop or a magnifying glass


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> First if its working sometimes and not others then its not the emulsion. Something is changing. Is it possible that you have always had the humidity issue. See info below
> 
> Moist emulsion will not be as sensitive as dry causing you to expose longer. If you are under exposed your screen will blow out, this includes if your emulsion is moist.
> 
> ...


Ok I'm honestly more confused now lol


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## sben763 (May 17, 2009)

There should be no confusion. Read the info above and test. Where is your location. If your in a high humidity area then you may have had a constant exposure do to the humidity being high and you were exposing long enough although not proper. Now you have dropped humidity your over exposing. 


Trust me on this. Unexposed emulsion washes out. If its not washing out then its exposed. Period. What can change is your environments, humidity, exposure lamps. I seen in a post you said it wasn't washing out so you increased the time. This is exactly backwards. Coat a screen dry it and wash it out. If all the emulsion comes off the emulsion is most likely good I have a test exposure PDF I'll try and upload in a bit I have to do from PC and I am on iPad now. It has 3 steps. Expose first for 1 min the move cardboard and expose another min and move card board again. You will have a step wedge test where the first area will be exposed 3 min and the last for 1 min. Wash out. If all wash out you will have to start with a longer time and retest. If you stabilize your humidity and your temp is between 70-90f then everything time wise should stay close to the same. If using unfiltered blacklights and its cooler out you may need to pre-warm the bulbs for 5 min then expose your screens as the cool weather can affect the bulbs. If your bulbs are 3 years old its time to change.


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## 20vK (Jul 9, 2011)

Ok. Get your dehumidifier on.

Get humidity to the low 40's. by this, we mean the area where your screens are. Make sure the hydrometer is with the screens, otherwise it is not measuring screen humidity and will be measuring the humidity if wherever it is.

Tape a coin to your screen.

If you have a stouffer strip or exposure calculator, tape that on too.

Edit: Sean says he has an exposure calculator and step wedge test. Tape that on too.

Expose.

Does the coin shape wash out?

We use a coin, because it is solid. No light passes through. This eliminates your positives from the equation, (which is a variable we don't want to deal with today).


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## 343paul (Jan 1, 2012)

Checklist for successful stencils:
1. Films are true black.
2. Emulsion is not expired. (It does go bad)
3. Screens were degreased after reclaim or new.
4. Drying environment has consistent low humidity and airflow prior to light exposure for at least 2 hours. Dry emulsion can resaturate with moisture if humidity spikes again.
5. Determine proper exposure time with an exposure calculator. Burn a coated screen with it taped on, rinse and calculate if you need to up or back off on exposure time. Invest in one if you havent. It is the ONLY WAY to figure out correct exposure time and prevent over/under exposure with your UV box.
6. Rinse and be happy!


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## Yasirm86 (Jan 22, 2012)

20vK said:


> Ok. Get your dehumidifier on.
> 
> Get humidity to the low 40's. by this, we mean the area where your screens are. Make sure the hydrometer is with the screens, otherwise it is not measuring screen humidity and will be measuring the humidity if wherever it is.
> 
> ...



I'm gojng to go check the humidity in a minute and then if it's high I'll go get a dehumidifier. 

One question. The yellow light I have is right above where I burn my screens and I leave my screens out after exposed it's dark just the yellow light on...can that be an issue??


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## 343paul (Jan 1, 2012)

Yellow light wont hurt screens


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## 20vK (Jul 9, 2011)

You already told us it was high. It was 56 in your garage yesterday, right? That's high. Go and buy a dehumidifier. You can't operate if your humidity is high. Control it, or you may as well give up now, because your screens will keep failing or will be inconsistent. Listen to the advice people with experience are giving you.

If nothing else, a dehumidifier may allow you to dry screens in under 2 hours, rather than overnight. That can only be a good thing when you are behind with work, right?

Go and buy one.

Now.

We can't give you any more advice until you do, because that's the most likely cause of your problems that just started...... As the humidity probably just started rising in your garage. See a trend?

Most yellow bulbs are safe.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> You already told us it was high. It was 56 in your garage yesterday, right? That's high. Go and buy a dehumidifier. You can't operate if your humidity is high. Control it, or you may as well give up now, because your screens will keep failing or will be inconsistent. Listen to the advice people with experience are giving you.
> 
> If nothing else, a dehumidifier may allow you to dry screens in under 2 hours, rather than overnight. That can only be a good thing when you are behind with work, right?
> 
> ...


Ok I was going to buy one last night and Walmart didn't have any, but just checked now and it was 67 went to 69 and now is at 64% humidity with 62 degrees now it jumped to 66 lol all within 5 minutes. So I'll go buy one today and let it sit.


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## 343paul (Jan 1, 2012)

60% humidity too high. Could be your problem


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## 20vK (Jul 9, 2011)

You will be so happy you did.

I bought one that had an internal bucket, but also allowed you to attach a hose to a drain, so you never have to empty it. That way it can run continuously.


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## Yasirm86 (Jan 22, 2012)

343paul said:


> 60% humidity too high. Could be your problem


Ok so I'll go get one and put it in the box till it drops lower. If it's always on while my screens are drying will that hurt the screens? I know it dries quicker with it, but if I do it overnight and I leave it on it's okay?


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## 343paul (Jan 1, 2012)

Wont hurt it overnight. Unless your dry box reaches 100+ degrees


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## 20vK (Jul 9, 2011)

See how long it takes. Maybe only 10 minutes, maybe an hour, maybe 2. You need to do the tests we already mentioned. Be scientific about it.

No you can't hurt your screens. But watch the temperature. These things sound like refrigerators and give off heat.


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## jimcr (Feb 3, 2009)

Yasirm86 said:


> Ok I was going to buy one last night and Walmart didn't have any, but just checked now and it was 67 went to 69 and now is at 64% humidity with 62 degrees now it jumped to 66 lol all within 5 minutes. So I'll go buy one today and let it sit.


your way too wet , but I would not rule out your emulsion. Ask your self this question " What changed scene I last had good screens"! Sounds like high humidity. Where are you located.
Something did. Like Sean said get your humility down to 40% and do a set test. that will tell all right there! Even if you done get a dehumidifier do the step wedge test , it should answer you questions with out fail.


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## Yasirm86 (Jan 22, 2012)

20vK said:


> See how long it takes. Maybe only 10 minutes, maybe an hour, maybe 2. You need to do the tests we already mentioned. Be scientific about it.
> 
> No you can't hurt your screens. But watch the temperature. These things sound like refrigerators and give off heat.


Ok one quick question. The weathered station I bought to tell temp/humidity. I place the sensor and the main unit in the box right? I took the main unit out briefly and put it on top of my press and I checked after a while and it said 43% humidity and then 39% I just placed it back inside the back I don't know if it has a reader or not on the main unit. So I have the sensor and unit both inside the box


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## sben763 (May 17, 2009)

It should have separate readings for the main unit and the remote sensor. What printer are you using and are you using all black or black with colors or only black. I post the correct file for a step wedge.


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> It should have separate readings for the main unit and the remote sensor. What printer are you using and are you using all black or black with colors or only black. I post the correct file for a step wedge.


So keep them in the same box then? I'm using all black epson photo 1400. Blackmax ink from ryonet


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## sben763 (May 17, 2009)

343paul said:


> 5. Determine proper exposure time with an exposure calculator. Burn a coated screen with it taped on, rinse and calculate if you need to up or back off on exposure time. Invest in one if you havent. It is the ONLY WAY to figure out correct exposure time and prevent over/under exposure with your UV box.



Paul info was spot on except #5. A calculator will get you in the ball park but a step wedge done with the film, printer and ink YOUR USING is the best test you can do so save your money on the calculator. 

Exposure calculators are marked with very clear film and a special film overlaid to creat the steps. The issue with this is most of us are using inkjets with waterproof film that has a milky appearance and isn't as clear as the calculator. Then the ink is a different density in how much UV it blocks. I believe this is measured in D-max. I have had my films read but have no idea how that's done. Mine were 2.0 and the calculator at 7 read 2.2 so my exposure wold have to be shorten slightly. As I wasn't blocking as much light. So in the whole testing I learned that doing a step wedge is far superior the a exposure calculator.


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## sben763 (May 17, 2009)

You can but I have my main unit in the shop and the remote in the dryer box. Do you have all channels black though. Are you running a rip. The file I will post will have halftones but already converted so no need for a Rip. But I need to know if your using all black channels


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> You can but I have my main unit in the shop and the remote in the dryer box. Do you have all channels black though. Are you running a rip. The file I will post will have halftones but already converted so no need for a Rip. But I need to know if your using all black channels


Ok I can move it. And yes all black with a rip. I've been to lowes, Home Depot, target, Walmart nobody sells dehumidifies lol


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## sben763 (May 17, 2009)

Home Depot should have them. I was at our local one today and the had them. If you have a Menards they are back in the appliance section. Ok don't print with your rip this PDF. Just print though standard printer dialog instead of the Accurip printer. Choose best photo and premium. Photo glossy paper setting. If your film are as dark as what comes out here you will need to play with the Accurip settings. I'll go to PC in a min and post file


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## sben763 (May 17, 2009)

run the 35 LPI on 110-156mesh yes I know that is pushing it on 110 but it will work with a proper exposure and a gentle washout The 45 LPI 180- 260mesh 65 LPI 280 and up

figure out the longest time you want to expose and divide by 3. use a piece of cardboard and leave just the 1st section to expose. expose the amount of time you got by dividing by 3 then uncover then next section and expose for the same time as the first. The repeat with the 3rd section uncovered. so if 3 min is you time then expose 1 min eac setion. the first section will be 3 min the second being 2 min and the 3 rd being 1 min. if they all blow out start with a higher time like 5 min and expose each section for 1min 40 sec, so your step will end up 100 sec each or 1 min 40 seconds, 3min 20 seconds and 5 min. after you find what washes out and what doesn't you can refine you steps to get a perfect exposure time. I use a pc microscope to inspect edges at 300x but a 10x loop or magnifying glass will do.

print file from corel or a graphics application like adobe Photoshop, Illustrator, gimp, inkscape with standard print driver using best photo and premium photo glossy, I use the 1400 and know these settings work well


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> run the 35 LPI on 110-156mesh yes I know that is pushing it on 110 but it will work with a proper exposure and a gentle washout The 45 LPI 180- 260mesh 65 LPI 280 and up
> 
> figure out the longest time you want to expose and divide by 3. use a piece of cardboard and leave just the 1st section to expose. expose the amount of time you got by dividing by 3 then uncover then next section and expose for the same time as the first. The repeat with the 3rd section uncovered. so if 3 min is you time then expose 1 min eac setion. the first section will be 3 min the second being 2 min and the 3 rd being 1 min. if they all blow out start with a higher time like 5 min and expose each section for 1min 40 sec, so your step will end up 100 sec each or 1 min 40 seconds, 3min 20 seconds and 5 min. after you find what washes out and what doesn't you can refine you steps to get a perfect exposure time. I use a pc microscope to inspect edges at 300x but a 10x loop or magnifying glass will do.
> 
> print file from corel or a graphics application like adobe Photoshop, Illustrator, gimp, inkscape with standard print driver using best photo and premium photo glossy, I use the 1400 and know these settings work well


Is it possible for you to give me a call??


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## sben763 (May 17, 2009)

Yasirm86 said:


> Is it possible for you to give me a call??


sure pm me your email. I will send you a email and in my signature will be my contact info including phone number


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## Yasirm86 (Jan 22, 2012)

sben763 said:


> sure pm me your email. I will send you a email and in my signature will be my contact info including phone number


I'm driving so here's my email [email protected]


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