DIY LED Exposure Unit: Testing


It’s finally time to show off the results…sort of.

I’ve decided to keep this post continuously updated based on testing new emulsion, mesh counts, processes, etc. Since this is an LED exposure unit that’s optimized to actually expose the emulsion rather than throw a bunch of light at it the burn times are very short and vary a few seconds here and there. That being said it’s a decent guide if you’re using about the same amount of strips (10-12) and exposure distance (~6″) as I did. So here are a few numbers to start:

Ryonet WBP Emulsion

I’ve been using this since I started off in screen printing and it’s been great when working with water based apparel and graphic inks. It’s a two part emulsion so it has a limited shelf life of about 3 months and exposes slower than others.

EXPOSURE TIME: 2:45-3:45

Cryocoat Emulsion

I got a free sample pint of this new emulsion from when I went to NBM Baltimore (Thanks Nick!). I knew I would be working on more DIY equipment and this would be the perfect emulsion for testing the exposure unit. This is a one part emulsion so no need to mix in diazo and it’s also LED optimized so it has low exposure times. I tried this out first on a unit with 2 UV CFL bulbs and it was horrible, I actually had to wash out half a dozen screens that were coated with it because it was too finicky. The LEDs made all the difference and the times went down to under a minute!

EXPOSURE TIME: 15-25 seconds

Note: Recently I’ve been having issues with exposures coming out scummy or not at all. This may be due to older low tension screens, improper humidity conditions, low temperature storage (basement), accidental light contamination or other factors I’m not even aware of. I’m fairly confident if I ordered a new batch it would work fine, but what’s the fun in that?

CCI LXP Emulsion

I’ve always admired Chemical Consultants Inc because they focus on a single group of products in the industry that aren’t as glamorous as some others but make absolutely all the difference. When I wanted to try out a new emulsion I decided to check out their new line of products and LXP that had just hit the market. If you’re looking to try it out Anthem Screen Printing Supplies sells it by the quart for $25 ($10 in shipping from SF to Bmore) rather than gallon.

I haven’t had a chance to test it out yet since it’s starting to get cold and dark earlier on the east coast and for now I have to reclaim and wash out in the backyard. I’ll try to get a few screens going in the next few weeks but until then, leave a comment if you have any experience with LXP or any other emulsions on LED exposure units.

Questions, comments or quotes? Shoot us an email and we’ll get back to you ASAP!

1 Comment

  1. Blake says: Reply

    Hi Matt,

    I’ve begun building an exposure unit following your guide, thanks so much for posting your progress!

    Did you add glass to the top of your unit? And if so did you buy a special glass for it? I’ve read that some glass can block UV light. I called my local glass company and sadly they didn’t even know what UV light was.

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