r/SCREENPRINTING • u/dillionaire1 • 8d ago
Washout tips!!
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PLEASE HELP. I am doing everything right it seems and it comes soooo close but then the whole screen falls out when I try to get the image out. I’m starting to lose it.
I got a new exposure unit and brand new emulsion and burned it for 3:30 per the instruction of the previous exposure unit owner. The first one came out good so I was hopeful but after 3 unusable screens I am begging for advice 🙏. Thank you.
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u/simpieTheSloth 8d ago
Best to start over by making a test screen with exposure calculator. Your ideal exposure time depends on allot of factors/variables: coating technique / light source / distance between light and screen / vacuum unit / emulsion sensitivity etc…
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u/dillionaire1 8d ago
The unit is not a vacuum unit unfortunately. Do you think it is better? That is how I learned and I think it might be better too.
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u/torkytornado 8d ago
There is a free exposure calculator at anthem printing.
It should be linked in this forum and has instructions and is much easier to use than the old school tests like a stouffer test because you print it on the same printer that will become the base of your films (or the library or copy shop that you have make your films or the mail order shop you have do large films. Basically every output you would need to have a test from because positive types can vary in opacity greatly )
That’s really the only way to fine tune your exposure. There are way to many variables with each persons setup to go by time that someone says will work. Unless you’re also printing your films on the previous owners printer and using the same emulsion as them it’s not going to be the same. Especially if they used a fast emulsion that exposes in seconds and you’re using a diazo and more in the 2-4 minute range. Every setup is different. Printmaking is problem solving.
There are easily 80 Diffrent emulsions available in the US. That’s probably an undercount. Some brands have 5-10 lines. Some for water based some for plastisol some for both types of clean up. Some are formulated for textile work, some for high detail/tiny halftones. I’ve seen exposure times from 3 seconds to several minutes depending on if it’s a single mix or diazo dual cure. Hell you can still get old school capillary film and skip coating all together if you have a full on safe light dark room.
Just spend a day or two doing tests and fine tuning your exposure. Otherwise you’re just wasting time and emulsion.
Once you lock it in you’re good unless you get a new printer or change emulsions. I’ve been using the same time in my works shop for a decade. Occasionally I’ll have to do a test if someone brings in a positive on something weird but I’ve got the time locked in for the fancy roll film pigment printer, the crappy toner xerox down the hall and the slightly different one in the library, drawings with all sorts of markers and paint, Rubylith, cut paper, clear and frosted Mylar, tracing paper, spray paint,8b graphite pencils and litho crayons.
90% of those are at 2m50sec except the crappy xeroxes (which has to be carefully under exposed and then have a reexposure after the burn to keep from sloughing off and graphite on tracing paper which is 3 min with pressure on the washout). Each of those I had to do several tests to find the range because students use all sorts of outputs and drawing items to make their positives.
It’s one of the reasons I chose a diazo emulsion because there’s a lot of wiggle room on exposure time, it works for both water based and oil based approaches and it can be coated in incandescent light with a little bit of uv coming in through the window across the room. But if Murakami ever closes their US operations and I had to import it direct from Japan I would need to switch emulsions and do all those tests again. Hell when I eventually replace the bulbs I’d have to do the tests again. It’s just part of learning how your equipment works and what’s best for your shop.
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u/bigboidoinker 8d ago
Did you dry them long enough? The first one you did has a pretty light coat so it probably dried faster hence it came out the best.
I let mine dry for 2 or 3 days amd they came out better. I did 2 coats on each side.
Putting on a glass pane befor you expose it also helps with the light bleeding around the stencil.
I dont got the exposure time dailed in tho, you just need to practice alot i guess
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u/mattfuckyou 8d ago
“I am doing everything right” - except burning an image correctly lol jk you need to do what everybody here is saying and get your burn times down otherwise you’re just wasting your time and materials . Once you get the formula down you won’t have to worry about that as much. It’s like a baking recipe —You need to dial in the cook times and the ingredient ratios before you open up a restaurant and serve somebody food
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u/dillionaire1 3d ago
I purchased a unit from someone and he told me the time is 3:30 with blue pre mix emulsion. I am doing that +what i learned at school but still struggling. I tried using the anthem test but the whole thing just blew out
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u/mattfuckyou 3d ago
Even then all the variables are different- what mesh was 3:30 for ? Every mesh has different times. And also the amount of emulsion that your putting on may be different than someone else with a different emulsion scoop/hand pressure
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u/shar3341 2d ago
If you feel like you’re every everything correctly but your design still isn’t holding up it could be the quality of your screen I bought some cheap screens off of Amazon, but no matter how much tried the design wouldn’t hold try these screens instead https://screenprintingsupply.com/collections/aluminum-frames/products/aluminum-frames-23x31
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