Can habitually underexposed screens be brought back to life?

[Stinkhorn Press]

Spent too long attending other parts of the business and let the screen room attempt to run itself. Time to reestablish control.

Many of my screens have images and crud on them. I think MOST of the crap on the screen is the result of long repeated UNDER-exposure.
Attached image is one. It’s ugly. It’s hard to deal with at every stage. Can mesh this abused be rehabilitated with some sort of chemical treatment/effort, or do I just need to buy new mesh?
…
We run a bank of tubes, 20x24 sized, 12 bulbs, old VNH Industries model exposure unit. Bulbs were last replaced June of 2014. Because 12 bulbs is $450 from Davis International Film, the one source I know (Light Emission Tech Brand F24T12/SDI/HO 24”).
Exposing 12-ish screens a day, 5 days a week, for almost 2 years and there’s not enough power to expose properly, which causes all sorts of havoc, especially in this case, of getting a good clean re-claim.

I have ordered new bulbs, but most of my mesh is damaged at this point. Any tips?

Emulsion: Ulano Proclaim w diazo (we run some discharge and don’t like multiple emulsions)
Screens: static T mesh, shurloc T mesh, and a couple shurloc murakami S mesh
Chemicals: easisolv 701 ink degrade, easisolv 500 emulsion remover, easisolv 840 on press wash, degreaser.


I also am setting up to run an auto (as well, exclusively, mostly, something…) and will need a different exposure unit anyway, for the 23x31 sized screens I’ll be needing for that.

[Sbrem]

I would look for a used Metal Halide, you won't turn back... it will cost more than 12 bulbs, and the bulbs themselves are costly and need replacement after many hours of use, but it's much better than tubes... I've only used Arc Lamps (in the '70's) and Metal Halide, I've never considered the tubes, even though I know they work, MH works a lot better...

Steve

[mimosatexas]

you can get a caustic dehaze like murakami 700 and it will clean it up.  I had to do that once on a round of older frames before i upgraded to metal halide.  You card it on the mesh horizontally on the squeegee side (since that is where the worse underexposure should be happening), let it sit for maybe 5 minutes, soft rinse, then pressure wash from the shirt side.  don't let it sit on too long and wear a mask, long gloves, and an apron since its nasty stuff.  The mesh will literally look and print like new.

[Stinkhorn Press]

I would look for a used Metal Halide, you won't turn back... it will cost more than 12 bulbs, and the bulbs themselves are costly and need replacement after many hours of use, but it's much better than tubes... I've only used Arc Lamps (in the '70's) and Metal Halide, I've never considered the tubes, even though I know they work, MH works a lot better...

Steve

That's my plan! How long do bulbs last? 6 months? a year? depending on usage?
Have my eye on this one on CL http://indianapolis.craigslist.org/bfs/5463804337.html, but it's 4 hours away and I've been a bit pressed for time lately. . .

[Stinkhorn Press]

you can get a caustic dehaze like murakami 700 and it will clean it up.  I had to do that once on a round of older frames before i upgraded to metal halide.  You card it on the mesh horizontally on the squeegee side (since that is where the worse underexposure should be happening), let it sit for maybe 5 minutes, soft rinse, then pressure wash from the shirt side.  don't let it sit on too long and wear a mask, long gloves, and an apron since its nasty stuff.  The mesh will literally look and print like new.

Oh that sounds lovely.

[Sbrem]

I would look for a used Metal Halide, you won't turn back... it will cost more than 12 bulbs, and the bulbs themselves are costly and need replacement after many hours of use, but it's much better than tubes... I've only used Arc Lamps (in the '70's) and Metal Halide, I've never considered the tubes, even though I know they work, MH works a lot better...

Steve

That's my plan! How long do bulbs last? 6 months? a year? depending on usage?
Have my eye on this one on CL http://indianapolis.craigslist.org/bfs/5463804337.html, but it's 4 hours away and I've been a bit pressed for time lately. . .

We make up to 150 screens a week, bulb replacement, $165.00 around 12 to 15 months. We usually notice the color is changing before we get bad results (my screen guy has 30 years under his belt, and 30 for my partner and 40 for me, so we've learned to notice subtle changes like that, NEVER stare at the light...) And that Teaneck you're looking at is probably pretty old, because we have a Teaneck giant vacuum frame, and it's a good 30 years old... Find out what bulb they use and look it up for pricing, or they'll probably give you the info. Good luck guy. Oh yeah, the haze remover will work too, but it's very caustic, wear protection, and don't leave it on too long like I did once, and lost 20 screens  that literally tore themselves apart, LOL...

Steve

[mimosatexas]

yea 5 minutes is plenty of time.  More and it will begin to eat the mesh.  Do them one at a time, not in batches so nothing slows you down and you end up losing screens.  Just do a few every couple days or something if it interferes with production time.