Using Strippers and Banishing Ghosts.

May 20, 2009

Post image for Using Strippers and Banishing Ghosts.

All screen printers do it, or at least they should.

Once or twice  a year I take the time to rejunvenate my screens. I try to wait until I start a brand new collection and when the weather turns nice enough to do outside. It is a labour intensive process but it totally rejunvenates my screens and so I save myself thousands of dollars by not having to have them all remeshed. Using two chemicals, a ghost or haze remover (which bleaches out the leftover images of other stencils) and then a screen wash (which gels the bleach and pigments to wash them away) I end up with almost brand new looking screens. Some commercial printers do it after each use of the screen but that’s not really necessary and in my opinion it’s a bit wasteful and puts an unnecessary load on the environment. I usually just do it only when it’s required. Which generally means my screens have so many old ghosts that they start to interfere with my new screens (clogging etc). Ghosting happens because with pigment printing as opposed to dye printing some of the pigments will stick to the screen fibres and not wash away even after reclaiming a screen (stripping away the emulsion). Eventually the pigments build up enough to clog the holes in the mesh. A lot of people don’t even know that you can rejuvenate screens and end up having their screens re-meshed. That’s an expensive process. My screens would cost me well over four thousand dollars to have re-meshed. But the rejuvenating chemicals cost only about $100.00 and should do all my screens two to three times. Well worth it.

p1020672

The brand I use is Tek 403 and 404 which is as environmentally friendly as these chemicals can be. That being said, the screen rejuvenator is a sort of  bleach and the fumes are strong enough that if you do it indoors you have to wear a vapour mask and goggles and your place will smell bad for a few days after. So I’m doing it outside. I recently finished my small screens and today I am doing my large ones. It will take all day but it’s going to be sunny (not too warm) so i don’t really mind.

Here’s what you’ll need to rejuvenate your screens:

  • Haze Remover and Screen Wash (screen wash is essential, some people skip it and to use soap but that never works)
  • Nylon Bristle Brush
  • Bucket
  • Heavy Duty Rubber Gloves
  • Pressure Washer
  • Protective Eyewear (regular glasses don’t count)
  • Vapour Mask (if you are working inside, or just to be safe if you’re pregnant or sensitive to chemicals and fumes)

Step 1

Put on your goggles, heavy duty gloves and vapor mask (vapor mask if working inside, goggles and gloves must be worn at all times regardless) Pour the rejuvenator into a glass or plastic bucket (one that will not be used for food again). If your rejunveator is a concentrate, mix it here.

p1020673

Step 2

Scrub the rejuvenator onto the screen using your nylon brush. Scrub onto both sides, flipping it upside down from one side to the next. Get and the surface area, even the corners. The rejuvenator needs to be left on for at least ten minutes. Since my screens are usually heavily soiled at this point I leave mine on for 2 to 3 hours or overnight. You’ll see that it dries to a whitish film. If you get it on anything that can bleach, like your clothes, I guarantee that it will. So wear old clothes and shoes too.

Once your rejuvenator has been on for the required amount of time scrub on the screen wash for both sides and let that dry for at least ten minutes. You’ll see that the screen wash turns to a gel like substance.

p1020675

Step 3

Get out your pressure washer. You’ll want to use this on it’s highest psi (at least 1600).

p1020676

Step 4

Start spraying your screen, slowly, from side to side working from the bottom to the top. Flip your screen over and repeat, try concentrating on spots that seem stubborn to remove. Your screen may not come completely perfectly white and you can do it again if you like but generally it will be good enough to start with another round of stencils.

p1020678

Step 5

Wash off your rejuvenated screens with soap and water to make sure all the chemical residue is gone and then let them dry.

p1020681

3M Easi-Air Paint Spray Respirator Assembly

The 3M Easi-Air Paint Spray Respirator Assembly includes two organic vapor cartridges, two paintspray filters, and one silicone facepiece. It’s NIOSH/MSHA approved for respiratory protection against mists of lacquers, enamels, and other paints.Complete instructions are included, which detail usage, approval labels, and product limitations. You can buy it here.
3M Easi-Air Paint Spray Respirator Assembly


You’re done! Happy printing!

“I am an Affiliate of Blick Art Materials”

StumbleUpon It!

{ 4 comments… read them below or add one }

nigel 11.23.09 at 12:39 pm

Love what you are doing here. All the tips, alerts and insights are very valuable when put into a comprhensible context.

I have just signed up to your mailing list and look forward to receiving anything from you. As well I will continuesly be on your site to see what’s new.

I will get to the point. I have not researched the de-haze and screen wash products that you use so I do not know how enviro they are. But you mention that they are as much as they can be. If you have any doubts do check out Franmar. They have a full line of screen cleaning chemicals that are all vegetable based. Mostly soy but I think some corn.

Also, what discharge system do you use?

Bye for now.

admin 11.24.09 at 2:12 pm

I don’t use discharge at this moment.

Robin Wagner 05.10.10 at 12:27 am

This stuff is even better and safe for the environment, easy on the hands and lungs. Works like a charm! I used to sue Diazo, what a useless product.

http://www.silkscreeningsupplies.com/site/799934/product/CCEWGAL

Jonathan 08.06.10 at 10:25 pm

Another very cool post about screen printing: I agree that you don’t need to and shouldn’t de-haze your screens every time you reuse them. Only when they get some decent hazing and staining. These days you can get de-hazers that are designed to wash down the public sewer system and be safely treated in the city water system. But you need to check with the manufacturer about that. Very nice post, thanks again for sharing your experience with others.

Leave a Comment

You can use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Previous post:

Next post: