Trying to Figure Out What I Am Doing Wrong

[laughingbuddha]

Hello Jonathan and All,

I recently got into screen printing. Up until now I've mostly cut vinyl stencils for smaller less intricate jobs but it's definitely a pain for detailed ones, however, the results have been perfect for what I've needed. Now that I have a more intricate job, I need to do an exposure.

I have this presensitized emulsion and did a 1-4 minute step test and had some issues with blowout. It's that HXT blue presensitized stuff. I have an exposure unit with 4 bulbs (one of those Lincoln ones) and adequate pressure. Everything done in a light safe environment.

The manual says 2 minutes should be good. All screens were coated and left to dry for 24hrs. 160 mesh coated 1:1. Washed out with cold water medium pressure from hose on flat.

Thank you all in advance for any insight you could provide. I have attached a photo of my attempt at the step test.

-The Fat Laughing Buddha

[Catspit Productions]

Hello there,

This looks like it could be a combination of issues. The first of which is emulsion to mesh adhesion.





You may also be spending too much time in the washout booth if your film positive is not dense enough. If the light can pass through the film positive in any degree it can semi cure the emulsion in the stencil area. This video shows you how to increase the density of your film positives using a "color rich black."



Those videos may help out. Also be sure to use a garden hose with cold tap water to washout the stencil. Never use a pressure washer or hot water.

Oh and one more thing... if none of that helps, try my Saati Textile PC Blue:

http://catspitscreenprintsupply.com/saa ... on-gallon/

http://catspitscreenprintsupply.com/saa ... ion-quart/

You can check out the customer reviews for this emulsion on both the quart and gallon listings.

[laughingbuddha]

Thank you for your quick answer.

I ordered some abrader and new emulsion from you and am going to see how it changes things.

Let me ask, could not abrading the mesh be the reason I need to expose for 3x as long as recommended by the emulsion manufacturer and my exposure unit manufacturer in order to get the emulsion not to wash off? I finally got a half decent exposure but some stuff still washed out at I exposed for 6 minutes.

Thanks again for your help and the videos!
-The Fat Laughing Buddha

[Catspit Productions]

You're very welcome. My pleasure to help out.

No, the mesh abrasion simply allows the emulsion to bit onto the threads. But it does not affect exposure times. Not abrading the mesh will cause loss of details or more where the emulsion comes off the mesh during washout.

Thank you for your order!