# Trouble with washing out exposed screen please help, emulsion flaking off



## DougieN13

I am new to screen printing, and coated a few screens and exposed them for quite a long time (20 mins) under my exposure unit, when i take it to the wash out i can see my design on the screen but when i wash the emulsion off bits round the edge of the design are flaking off

what am i doing wrong?

does it mean the screens are not dryed properly before i expose them?

any help would be great 

am getting disheartened with it : [


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## brent

Don't get disheartened. You are new. I knew nothing when I started, now people call me for advice. You'll learn as you go, there's just a lot to learn!

Anyway, your screens may have been greasy when you coated them, so the emulsion didn't stick well. Try a degreaser before you coat them.

It also might not have been dried properly, possibly dried only on the outside of the emulsion, not the inner part on the mesh. Try letting them dry longer.

Does your film/transparency have nice clean crisp lines of the design, or is it sort of fading? Nice sharp edges burn best.

How are you burning? did you build a unit? If so, what's it like?


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## Sheepsalt

20 mins is a long time, even if you're using a halogen bulb. 

There are so many variables, so if you could post exactly what you are doing it would help nail down where the exact problem may be.

Stuart's advice was spot on, too.

1. Start with a fully-opaque film - you should see no light through the print on the film when you hold it up to a light.

2. You need to thoroughly degrease your screens before you coat them. Scrub them with a degreaser using a pad or brush that you only use for degreasing. Scrub both sides for several minutes, going in every direction, and make sure you rinse them very thoroughly. Then make sure they are 100% bone dry before you move on - put a fan on the screen and leave it for quite a while. Don't touch the mesh with your fingers at all once they have been degreased.

3. Coat both sides of the screen with emulsion using a scoop coater, and set the screen horizontally to dry. Again, put a fan on low to blow air across the screen as it dries. Best to let them sit for several hours, maybe more depending on the relative humidity where you live.

4. Make sure your film is held flat against the screen and can't move during exposure. Tape it in place with clear tape. What type of exposure unit are you using? What type of emulsion are you using?

5. Rinse out the stencil - wet both sides of the screen, wait 30 seconds, then spray out the stencil area spraying from the shirt side. A garden hose with a good spray nozzle works pretty good for most emulsions. If you're using a pressure washer, make sure you're not getting the nozzle right up close to the screen. The emulsion is a bit soft from the water, and can blow out with enough pressure even where there was exposure.

Again, it will help to know exactly what you're doing now and what products you're using, but definitely don't get discouraged... just keep learning!


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## DougieN13

brent said:


> Don't get disheartened. You are new. I knew nothing when I started, now people call me for advice. You'll learn as you go, there's just a lot to learn!
> 
> Anyway, your screens may have been greasy when you coated them, so the emulsion didn't stick well. Try a degreaser before you coat them.
> 
> It also might not have been dried properly, possibly dried only on the outside of the emulsion, not the inner part on the mesh. Try letting them dry longer.
> 
> Does your film/transparency have nice clean crisp lines of the design, or is it sort of fading? Nice sharp edges burn best.
> 
> How are you burning? did you build a unit? If so, what's it like?



i am using this exposure unit
Wicked Printing Stuff Website

i did think 20 minutes is a bit long

i managed to do a successful one lastnight, i had left the screens to dry longer and it helped lots, also from reading up on different threads i didnt realise the emulsion comes off where the design is more from the mixing of the water and the emulsion rather than the pressure of the water, so i took more time washin it out at a less pressure and seemed to work better.

Thanks for your help mate


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## DougieN13

Sheepsalt said:


> 20 mins is a long time, even if you're using a halogen bulb.
> 
> There are so many variables, so if you could post exactly what you are doing it would help nail down where the exact problem may be.
> 
> Stuart's advice was spot on, too.
> 
> 1. Start with a fully-opaque film - you should see no light through the print on the film when you hold it up to a light.
> 
> 2. You need to thoroughly degrease your screens before you coat them. Scrub them with a degreaser using a pad or brush that you only use for degreasing. Scrub both sides for several minutes, going in every direction, and make sure you rinse them very thoroughly. Then make sure they are 100% bone dry before you move on - put a fan on the screen and leave it for quite a while. Don't touch the mesh with your fingers at all once they have been degreased.
> 
> 3. Coat both sides of the screen with emulsion using a scoop coater, and set the screen horizontally to dry. Again, put a fan on low to blow air across the screen as it dries. Best to let them sit for several hours, maybe more depending on the relative humidity where you live.
> 
> 4. Make sure your film is held flat against the screen and can't move during exposure. Tape it in place with clear tape. What type of exposure unit are you using? What type of emulsion are you using?
> 
> 5. Rinse out the stencil - wet both sides of the screen, wait 30 seconds, then spray out the stencil area spraying from the shirt side. A garden hose with a good spray nozzle works pretty good for most emulsions. If you're using a pressure washer, make sure you're not getting the nozzle right up close to the screen. The emulsion is a bit soft from the water, and can blow out with enough pressure even where there was exposure.
> 
> Again, it will help to know exactly what you're doing now and what products you're using, but definitely don't get discouraged... just keep learning!



thanks for the information, i didnt realise that degreasing the screen so much was so important

my emulsion and exposure unit was from this website Wicked Printing Stuff Website

il keep practicing, the screens are getting better each time


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## Sheepsalt

Looks like you've got a 1,000 watt halogen bulb for exposure - if you're using a dual-cure diazo type emulsion it shouldn't take more than 12 1/2 minutes. Shorter for higher mesh counts.


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## DougieN13

Sheepsalt said:


> Looks like you've got a 1,000 watt halogen bulb for exposure - if you're using a dual-cure diazo type emulsion it shouldn't take more than 12 1/2 minutes. Shorter for higher mesh counts.


ah il try 12 minutes

iv done a couple of successful screens now with 18-20 mins

what happens if you over expose?
do you lose detail in the design?
my designs have been pretty plain so far


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## Scott747

Make sure and do one of the exposure tests to make sure you have the correct timing...


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## Nietzsche

I too am new to this business and run into questions on about everything I do. For instance:My transparencies are sticking to my screen after I burn them and pulling the ink off my transparancies. How do I prevent this from happening?
Thanks


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## moffett8

Let the screen try longer. You are not letting the screen dry long enough. Try using a fan or a small electric heater to help speed the drying process just don't put the heater too close.

Philip


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## Nietzsche

Thank you for the info. Since I started having this problem I've revamped my dark room. I now have a de-humidifier and a set of fans in the room. It has helped in the biggest way.
Thanks again.


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## rcuellar1

hi an any one help i just started to do screen printing by watching videos on youtube. i put emulsion on the screen let it dry for a whole night and then burned my image.for 5 min with a plate maker burner machine when removed no image appears on the screen and when i wash out the whole emulsion washes off what am i doing wrong or is there anything else i need to add to the emulsion pls help as i dont know what to do can u all tell me where to buy the cheapest blank t shirt i dont have a tax id cause im not registered i have it in my garage thanks


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## chasamax

rcuellar1 said:


> hi an any one help i just started to do screen printing by watching videos on youtube. i put emulsion on the screen let it dry for a whole night and then burned my image.for 5 min with a plate maker burner machine when removed no image appears on the screen and when i wash out the whole emulsion washes off what am i doing wrong or is there anything else i need to add to the emulsion pls help as i dont know what to do can u all tell me where to buy the cheapest blank t shirt i dont have a tax id cause im not registered i have it in my garage thanks


I could attempt to lend a hand but it would be very difficult to pinpoint a single problem. If you have watched videos on Youtube than you probably realized that they don't use a plate maker burner for exposure ( I tried searching to see what that even is but to no avail). I would surely start there.

1. If you are on a budget, try picking up a halogen work light.. they are pretty cheap at your local hardware store. I don't use one but there are a lot of people on here that do, and I am sure they can assist with some sort of exposure time.

2. In regards to cheap t-shirts, t-shirtwholesaler.com is decent.. 

3. And the emulsion washing off could be numerous factors but what it sounds like to me is exposure time. I use a 6 - 15 watt unfiltered uv black light exposure unit and my average exposure time is about 8 1/2 minutes - your using a 'plate maker burner machine' so the exposure time should be somewhere between three days to literally burning your image onto your screen. 

4. Also, what are you using to make your positives (images)?

I would probably type less but I have pulled an all-nighter on a print job.. so I am rambling.

Lastly, anything Richard Greaves posts in these forums you should search for and read... he's helped me a ton just by his posts. Some day I am going to send him a plate of cookies, don't worry Mr. Greaves, my wife will make them.


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## foot print

Nietzsche said:


> I too am new to this business and run into questions on about everything I do. For instance:My transparencies are sticking to my screen after I burn them and pulling the ink off my transparancies. How do I prevent this from happening?
> Thanks


 lets your films dry longer...what side of the film are you printing on..? Films have to sides a smooth side and the side with a little bit of texture...make sure you print on the side that has a little bit of texture. What type of film do you use...? I use Fixxons film that stuff is great and at a great price. Also make sure your coated screens are dried completely. I use a small space heater inside a drying box i made really speeds up the process.


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## chasamax

I am going to step out on a limb and say the problem isn't with his films, but with his 'not very dry' emulsion. 

If you are using an inkjet printer and you print on the wrong side you will typically get really wet ink that essentially pools on the surface. The best way to check on which side you need to print on is by licking your thumb and pointer and grab the transparency.. the finger that sticks is the side you print on.

Ok, back to the sticky positive - if your emulsion isn't dried enough, your positive will stick to it and not only did you potentially ruin your positive but you also wasted emulsion, cleaning supplies, and lots of time.

Make sure your screens dry overnight in a controlled environment if possible - and make sure you use a 21-step strip when exposing, it will save you a ton of money in the long run.


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## jjjester

DougieN13 said:


> ah il try 12 minutes
> 
> iv done a couple of successful screens now with 18-20 mins
> 
> what happens if you over expose?
> do you lose detail in the design?
> my designs have been pretty plain so far


I have the same question, what happens if you over expose?


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## starchild

Nietzsche said:


> Thank you for the info. Since I started having this problem I've revamped my dark room. I now have a de-humidifier and a set of fans in the room. It has helped in the biggest way.
> Thanks again.


Using fans in your drying area/darkroom will introduce dust and you will start seeing pin holes in your screens after exposing. 

Lights and moisture are not the only things that need to be "enviromentally controlled."


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## JimGilbert

jjjester said:


> I have the same question, what happens if you over expose?


Being a newbee also, I did my best screens yesterday. My first one was real good but then I couldn't burn one for nothing... tried about 10 before I found the problems:

1. film quality - I found that with my Canon i9900 "black" comes from the "black" cartridge. The print is good but you can see through it too easily.

I made a new color in Corel and specified 100% of CMYK (all 4). This "mixes" a real black. Then I printed the transparency, added a 4px white outline to all of the objects and printed it again... yes, twice on the same film... and it worked great.

2. exposure time - I was cooking them too long. I had to really force the emulsion out with pressure and then the edges were not clean. I have six 20w 24" unfiltered black lights about 5" from the glass, use Photo Blue emulsion, coating only on the shirt side. I tried starting at 5 minutes and worked my way down to 30 seconds for good exposure on white screens. For the two at 30 seconds the emulsion washed out easily without anything other than moderate water pressure. These two are 110 mesh screen and they came out very crisp.

Question - does exposure time vary depending on the mesh also - higher mesh takes longer?

I was told that yellow screens take about 50% longer exposure time.

Jim


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## palmercader

I am new t-shirt printing my problem is how to washout emulsions on screen with detailed images/designs like the CMYK. How much pressure of water should I use for washing out the screens? Thank you in advance.


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## Bishsrealdeals

I see this thread is a bit old but it was the only thing that came up when I searched for solutions to this problem.

Like many of the people who posted in this thread, I am brand-spankin new to screen printing. I've actually only attempted 2 thus far and both times the emulsion around the image has flaked off as I was rinsing the image out. The first one, I believe now after reading, flaked because I had too much water pressure. The second one though, I'm still not sure because I took more time and less pressure rinsing it out and it still flaked on me. I did not think to use degreaser on either of them. Is there a specific kind to use? also I my dry time for the emulsion has been about 2 hours in a dark room with a small space heater. It is completely dry to the touch so, being new, I assume it is dry and ready for exposure.

I have rigged up my own exposure unit using a non filtered halogen work lamp. In one of the instructional youtube videos I watched, a man using a similar exposure unit said to expose the image on the screen for about 30-45 minutes. The first screen I exposed for about 45min. When it flaked off I thought it may not have exposed long enough so the second screen I kept under the unit for a little over an hour. What is the right amount of exposure time? and After the image has been exposed on the screen, is there a time frame or wait time for rinsing the stencil out??

Any help/advice will be much appreciated!!!


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## Greatzky

you have to degrease your screens before coating. everything you spray or scrub on them as well as everything that touches your screens will leave reside behind and that will cause an issue when trying to get emulsion to adhere to the threads of your mesh.
You can use any industry degreaser or you can use something like simple green.
I've never dried a screen after coating for less than 6 hours before exposure. You only need enough time for the emulsion to dry, but out of habit I coat overnight or wait 4-6 hours. the place that I store my screens doesn't have humidity control so it can get humid especially when it rains. 
I can't possibly see any reason that you would need to expose your screen for 30-45 minutes. if you are doing that you are using the wrong type of light. Make sure to remove the glass shielding from the exposure unit if it's a work light style unit like this:








How far away is your light source from your screen? what is the wattage of your bulb? it should be around 500 watts or more. 

With a standard shop light, like what you get in beginners kits, I was exposing 110 mesh screens coated once on each side for 6 minutes. With my new exposure unit I'm at 1 minute for a 110.


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## Bishsrealdeals

First off thank you for replying, your advice is very helpful. The lamp is approx. 2' away from the surface of the screen. It is a 500W bulb work lamp.


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## DIRKDELAN

sori po sir ngayon lang ako naka open ulit na bz lang po..mga sir may tanong po ako sana matulungan nyu po ako...pag katapos ko po mag burn sa screen ko .nang hinugasan ko ang screen nag wash out lahat ng design two times ko po ginawa wash out parin,,,ang emulsion na gamit ko po ay cpa emulsio at sensitiser..1 is to 9 po ang mix ko at nag burn po ako ng halos 12 minuto,ang ilaw ko po ay 2 pcs 100watts bulb,ang distance po nya sa sa screen ay mga 12 inches..at ilang oras po ba mag expose sa screen pag gumagamit ng electric fan?...sana matulungan nyu po ako mga sir..salamat po godbless...may customer na po kac ako 30pcs shirt kailangan ko i print..


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## Innovativedesign

hey guys, sorry to jump into your thread but I'm having the same problem with my chromatech wr emulsion will not able to washout completely until I rub image with my nail. I tried exposing it 4 min. all the way to 15min but seems to have the same problem.


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## Hydrogin

Instead of my emulsion flaking my emulsion just washes out i tried drying it for a full day with a fan 10- 15 mins of exposure and nothing just washes away i have my image facing the smooth side (wrong way) but im sure thats not a big prob do i let my image dry longer with a heater? I need anwsers both my 1st times it washed out only the 1st one i let it dry for 4 hours still washed out but not as easily as the one i let dry for 24 hours (note i did use a halogen bulb from Screen Printing Supplies & Equipment | ScreenPrinting.com by Ryonet the 1st time it broke and used my light bulb for the 2nd


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## screenprinter121

Hi there! I'm having the same problem. Lately the emulsion washes right out after exposure and I wash the screen. I've never had that happen before but recently it's been doing that each time. Maybe Im not coating enough emulsion on the screen? I recently switched from speedball to jacquard emulsion-any thoughts there?


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