# Please help before I go insane.



## Bella2132 (Oct 16, 2015)

Hi!!!
Am desperately in need of some help and advice.
So basically I've just brought a screen printing business, for the last 2 weeks I've had to learn everything, a steep learning curve!
So basically I think I'm 90% there but the main issue is after exposing my screen and doing a few a prints if and when I need to clean the screen my emulsion is coming off leaving me at square one again! 
So . . .the screens I'm using is UK 43T I wash and degrease it, coat it in autosol 5000 one coat each side thin and even (i do it in the dark). I then leave it to dry in a rack that's covered with velcro 'd blackout fabric with a small fan running. The time varies but minimum is 24hrs to dry. Then in the dark, I place my acetate substrate side keeping it in place with celotape then I place it onto the exposure unit. This is essentially a box with 3 UV unfiltered black light tubes(20 W) in it, these are about 6inchs from the glass. I place my frame substrate side down onto the glass, put a piece of foam in the frame, then cover the entire exposure unit in blackout fabric. I used an exposure calculator which said anywhere between 12 and 16 minutes was good so I expose for 14 minutes. I then put the frame in the washout booth and have to use a garden Hose spray attachment as the pressure washer just demolishes the emulsion. But even with the garden spray attachment I have to go unbelievably carefully or else emulsion comes away from the image. If this has worked I then let the frame dry, normally in the carousel arm with a fan blowing. Then when dry a quick check for pin holes etc using speedball screen filler, I leave this to dry under a 500W halogen lamp (as heard a post expose can help to harden the emulsion) then when it's completely dry tape up edges etc normally at this point the screen works well printing clear lovely images, but when and if something happens and the screen needs cleaning if I go anywhere near the substrate side the emulsion comes away meaning I have to expose another screen. So far I've tried plastisol, waterbased and HS-A paints cleaning with white spirits for the first water for the later. Please please please can someone help, I'm getting runs of 25tshirts done then having to expose new screens which is just not viable for business time or in fact my sanity!
Thanks annabelle


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## PatWibble (Mar 7, 2014)

Bella2132 said:


> Hi!!!
> Am desperately in need of some help and advice.
> So basically I've just brought a screen printing business, for the last 2 weeks I've had to learn everything, a steep learning curve!
> So basically I think I'm 90% there but the main issue is after exposing my screen and doing a few a prints if and when I need to clean the screen my emulsion is coming off leaving me at square one again!
> ...


Sounds like you are under exposing the screens.
Never used fluoro tubes to expose screens, but three is not enough, and 6 inches is too far from the glass. Chances are the glass will also be filtering a good deal of the UV light.

If you have a 500w halogen why don't you just use that?
Remove the glass from the lamp and set it about 8 - 12" above the screen. Do a dummy run with an uncoated screen to set the distance - make sure that the entire screen is in the brightest part of the beam.

It should take 6 - 7mins to expose ( never used your emulsion, so some experimenting will be needed).

Always use a garden hose to wash out, a power washer is too powerful. Rinse each side for a few seconds, and leave for a minute or so to soften the image area.


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## Viper Graphics (Mar 28, 2009)

I agree with Pat, sound like underexposing. I use a halogen 500w and it is about 10-12 inched above the screen when I expose. I use ChromaBlue emulsion and 5-6 minutes works perfect every time (based on screen mesh size and detail of print). If you get a halogen set up make sure you remove the glass in the housing as it has a UV block (at least mine did) and can cause you more problems. I can wash out with just a light spray from a hose. Good luck


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## Ready2Rock (Jan 30, 2014)

Agree with the above but will add one more thing. Are you sure the emulsion is completely dry? I know you said you're drying for 24 minimum with a fan but we tried using only fans to dry and found out quick we needed a good size dehumidifier just for drying the screens.

Good luck!


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## Domenic (Jun 15, 2015)

Bella,
I would talk to the company you bought the emulsion from...they should be able to tell you what is wrong?


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## NoXid (Apr 4, 2011)

Emulsion does have an expiration date, so if this is something that came with the business, maybe it is too old. 

... okay, looked it up.
Autosol 5000 | MacDermid Autotype
So that is a Dual Cure. Does it have the Diazo added? That makes it tough enough to hold up to waterbased inks ... it also starts the Clock-O-Death as once the Diazo is added it has a shorter shelf life.


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## Printor (Apr 16, 2015)

I to think it sounds like underexposure or expired emulsion. By the way, post exposure has absolutely no effect on duel cure emulsions. It's just a waste of time and electricity.


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## PatWibble (Mar 7, 2014)

The shelf life of the emulsion is a very valid point.

Also, make sure that your drying cabinet has some ventilation to stop things overheating. Excess heat (when drying) can effect the way some emulsions behave. One of the brands I use - Thanet Coatings Tc6016 - recommends temperatures stay below 35c (99f) in the cabinet.


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## Bella2132 (Oct 16, 2015)

Thanks for all the advice, the glass on the UV exposure unit is unfiltered and the emulsion is new. It's a cold fan running so definately won't get too hot, am going to bring the UV lights up (I.e reduce distance) get more of them. When I brought the business the previous owner was using a halogen lamp 500W but I wasn't getting good clear crisp images. Thanks for the post exposure advice!!!
Did some research last night, has anyone used the emulsion hardener before? Know it's meant for longer print runs but may be a good short term option until ive resolved this problem. Went into full geek mode watching videos about discharge paint last night has anyone used it?


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## PatWibble (Mar 7, 2014)

Emulsion hardener can make it difficult to impossible to reclaim the screen, so you might loose a few screens. 
Sorting your problem is probably the best option. If you look at the commercially available tube based systems, the tubes are directly under the glass, and only a few inches apart.

Apart from the clarity issues, when you use the 500w halogen are you getting a good durable exposure, or is the screen still washing out in the same way as it is now? If you still get a problem then the emulsion might have been hanging around at the suppliers for too long, or have been badly stored by them.

The crispness of the image when using the 500w lamp will be down to lack of intimate contact between the screen and the film. Until you get your other exposure sorted, try using a very small amount of spray tack to hold the film to the screen. To do this you will need to flip your image before you print the film, so that the uncoated side of the film is in contact with the screen ( the spray tack will effect the coating on the film).

Discharge ink is a learning curve all of its own. The results are nice, especially when selling to fashion brands, but are more than is needed for general day to day work. Something to consider for the future.


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## Kelin (Oct 16, 2015)

i agree with you all but Are you sure the emulsion is completely dry? I know you said you're drying for 24 minimum with a fan but we tried using only fans to dry and found out quick we needed a good size dehumidifier just for drying the screens.


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## NoXid (Apr 4, 2011)

3 UV tubes is not enough. A commercial unit for regular sized screens would have 7. With only 3 you have to have the screen a good distance away in order for the light to "evenly" cover the screen (still won't be that even), but that also reduces the effective output. Go closer with only 3 tubes and some parts of the screen will be overexposed while other parts are underexposed.

I would use the halogen or add more tubes to the existing unit and move them closer to the glass. Look at photos of commercial units online to see the number of bulbs and how close together and close to the glass they are.


?? Did you add the Diazo powder to the emulsion? That part is not premixed, gotta do it yourself to get the _dual_ cure.


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## ParrotPrinting (Feb 23, 2015)

There is one thing I'd like to add that nobody touched on......get a bug light you don't need to do all this in the dark


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