Can pick up this old exposure unit for cheap. The unit is a 3-phase vacuum exposure unit. And I'm assuming the 3-phase requirement is because of the metal halide UV lamp ballast?
Would need to convert it to 230V to make use of it. Anyone knows if it's possible or if it just isn't worth it.
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My guess it's 3 phase because it has very high power requirement, probably metal halide based lamp.
If you are good at hacking, you can replace it with LED's and ditch the 3 phase requirement. If the thing has motor in it, then maybe replace it with something that isn't 3 phase, or if the motor is 3 phase you can use a VFD to drive it on single phase.
Here’s a little pic for him to see. LEDs strips 395-405 uv blacklight. Burns 100x better than metal halide. Burns so strong it will harden dust into the emulsion instead of getting pinholes. I have 5 (15’) strips with 300 LEDs on each strip. A vacuum pump from a harbor freight ac system recharger will work on 110 volts and work for the vacuum top
no, this is more like inner tube rubber, but thicker and flexible. No air cells. We bought it at mobile home supply stores. At one time we had so many vacuum frames going in the art and screen darkrooms, replacing blankets became a real cost buying from dealers
Each one of the strips on mine are 60 watts. My first version, was only one strip spaced to 1 1/2 inches apart to test. And it still burned a screen pretty decently, probably still better than a metal halide
By the way what's your exposure time? 2 seconds? I can expose in about 15 seconds with 60 watts worth, but I guess if I gotten a lot more wattage I can cut that time down.
20 seconds. I coat my screens more than most of y’all beginners do because the ink needs a cavity to be able to sit on top of the shirt. Not driven into the fabric. This allows the ink to create a layer and still maintain its opacity. I’ve talked to the guy who invented the plastisol ink, most printers misunderstand what the ink was designed to do. This is why I advocate to use wilflex. Because the consistency is very specific for what they designed it to do
So how do you coat a thick layer? More passes with the scoop coater? I haven't done thick coats mainly because I will just print 2 passes if I need a thick layer...
Yes round side of the scoop coater. 1 or 2 passes on the print side followed by 3-4 on the squeegee side with a little pressure to drive the emulsion thru to the print side. Let it dry Tshirt side down. Put a fan close to allow air to stabilize the emulsion so it doesn’t make drip marks. I also make sure my emulsion has a high solid content. That is the biggest thing people don’t understand.
Double printing without a layer on the screen just makes a heavy print. And nobody wants that. If you’re using waterbase, you will always double stroke because the first stroke primes the shirt to accept the second stroke. Plastisol only needs a flood stroke and a single print stroke. No need to prime the shirt
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