[nappilyevrafter]

After a few very frustrating tries at making a screen, I think now the problem may be my transparencies aren't dark enough. When I go to wash the image out after burning, it won't wash out. After 3-4 minutes of spraying, I switched to hot water and got a couple spots to wash out, but too much emulsion was washing out then.

I need to reclaim this screen and try again now with better quality transparencies. Should I re-expose the screen before I reclaim it, to make sure the emulsion will respond to the remover? There are a lot of areas that were supposed to wash out, but didn't, and these areas were very hard to clean after the first time I messed this up.

I recently moved to a new space and lost most of my stuff, so I'm using new emulsion (KIWOCOL POLY PLUS Z), a new screen, and a new way of printing transparencies (Same plastic paper they use at Kinko's, possible different ink from my mom's laser printer though). I had to re-set up a clear 200 watt bulb, exposing for 45 minutes at 12 inches has been working fine for me in the past, I don't think that's the problem..

So: Should I re-expose this screen before I reclaim it? It's just been washed with water so far, and the under-exposed part (that was supposed to wash out) will be very hard to get off, as was my experience last time. Thanks for any pointers!

(And if someone could recommend a good screenwash to get the emulsion out, I would appreciate it, thanks!)

 

[mrvixx]

Just reclaim it.

 

[nappilyevrafter]

Last time it was REALLY hard to get the under-exposed areas out, I ended up rubbing my fingers raw on those parts because the under-exposed emulsion wasn't responding to the remover, spraying and scrubbing weren't working, just rubbing it hard with my firgertips and really hot water worked.. Any tips on reclaiming? Or could you recommend a good emulsion remover?

 

[odil1372]

Underexposed emulsion is easier to wash out by nature. That's not your problem.

 

[mrvixx]

Use a pressure washer.

 

[nappilyevrafter]

Underexposed emulsion is easier to wash out by nature. That's not your problem.

I understand that under-exposed emulsion is harder to remove. So, should I expose this screen after washing it with water, to make reclaiming easier?

Here's what I've found so far on this topic:

Q1:Why isn't my stencil remover working?
It is very important to never let the stencil remover dry. It locks the stencil in the mesh with a permanent chemical bond.

***Under exposed stencils are harder to remove than completely cured/exposed stencils.***

Under exposed means some of the sensitizer did not cross link. This is always on the inside of the stencil because invisible UV energy didn't have enough time to move all the way through the stencil to the inside. Penetration of UV energy is not 'linear'. The deeper the UV energy has to penetrate, the longer it takes based on the physics rule called the Inverse Square Law. If you double a distance energy has to travel, it takes 4 times the energy - NOT double. Many low energy UV lamps may never penetrate a thick stencil.

When you spray stencil remover on the stencil, it has to penetrate and attack the chemical crosslinks formed by UV exposure. No crosslinks - no easy stencil removal.

The stencil remover chemical creates another reaction with under-exposed stencil and forms a chemical bond with the mesh that is very difficult to remove.

Q3: ?
Penetration
***Fully, or even over exposed screens, actually reclaim easier than under exposed screens.***
Screen makers under-exposure to keep fine lines fro closing up and choking the actual ink print. Under exposure does reduce that problem, but at the cost of stencil durability and the ability to reclaim the stencil.

***Many reclaiming problems result from mistakes made earlier, during the stencil-making process. Chief among these is underexposing the emulsion. Underexposed emulsion can be virtually locked to the threads of the mesh and may resist all efforts to reclaim it.*** The solution is to buy and learn how to use an exposure calculator or 21 Step Gray scale to measure stencil hardness.

Any tips on reclaiming under-exposed emulsion? Rubbing it hard with my fingertips worked, but my fingers are raw now. Thanks!

 

[n.signia]

No, underexposed emulsion is very easy to remove, not harder. If your having a hard time reclaiming under exposure is not you problem. Also, if your image is not washing out, your problem is over exposure, not under exposure. For your films, use waterproof film from ulano or ryonet, and print them on an Epson 1400, this combo will give you great films on the cheap.

 

[odil1372]

Get a power washer, dude.

 

[DavidRobison]

Yeah what was said earlier is important. If you apply emulsion remover to the screen and then let it dry before washing it out even an awesome pressure washer will not help. ALWAYS use the emulsion remover on both sides of the screen give it maybe 30 seconds or a minute to work, We use a plastic scrub pad to work the emulsion remover into the emulsion on both sides of the screen. Then hit it with a hose or pressure washer and it should fall right out. Lastly check your emulsion remover, did you mix it from a concentrate? and if so did you mix it right? Very weakly mixed remover is worthless, we always mix ours a little stronger than recommended to speed up the process. 20-1 mix we do as a 15-1 etc. Good Luck

 

[UniqueInk805]

I've used Franmar emulsion remover and a pressure washer and usually have no problem getting the emulsion off. If it's under exposed it should come off a lot easier than if it was over exposed. I dont think the problem is with it being under exposed...

 

[BIGRICH74]

Ulano screen wash works great for me. I spray both sides of the screen and give it about 20 seconds before I scrub both sides. I bought a pressure wand for $20.00 at CVS and connected it to my garden hose and it works just as good as a pressure washer.