CLOGGED SCREENS

[mooseman]

Not sure if anyone else has seen this but I thought I would share what we run into time to time.
The picture below shows a fresh screen test print white ink through a 156 screen.
The arrows show the result of a clogged screen that showed no indication of blockage (none that i noticed anyway) preventing a good ink deposit.
We see this every now and then and have tried several means to open the screen.
Ink wash, screen opener, lacquer thinner, jack hammer, nuclear weapons..................

What we ultimately figured out is the blockage was caused my dried minerals in our water. This is kind of unusual as we have municipal water, it is not hard and give no indications in laundry or washing dishes of any mineral deposits.

The second picture is the solution that is the solution to the problem. Works like a charm screen opens after a couple of wipes and ink flows nicely.
Just thought we would share for what it is worth.
mooseman

[numbercruncher]

Yikes - go figure...type of emulsion used ? any effect on the emulsion?

[mooseman]

Yikes - go figure...type of emulsion used ? any effect on the emulsion?

The emulsion is Ulano Orange. We get pretty good EOM, (sorry no ability to measure) and no deterioration to the emulsion from the product we used. Ulano Orange is not waterproof but all indications are the edges and thickness of the emulsion in the treated area were not damaged. Additionally there was no transfer of emulsion to the cloth we used to treat the area. Literally it is a wipe on and wipe off process one or two times then cloth dry.
mooseman

[Sbrem]

Perhaps a simple filter setup on the incoming supply?

Steve

[blue moon]

are you sure it's not scumming? It sure sounds like it. . .

pierre

[BP]

I think Blue Moon is right. I use Orange as well. Try a wet rag to wipe it.

[3Deep]

I've had scumming in screens from not rinsing the screen good or not towel drying the water out the open area, what has work for me is spit believe it or not just wet my fingers and rub the area, crazy yeah but it works

[blue moon]

I've had scumming in screens from not rinsing the screen good or not towel drying the water out the open area, what has work for me is spit believe it or not just wet my fingers and rub the area, crazy yeah but it works

yes, water will get it out as long as it's before you put ink on it. Once it's inked, water does not work . . .

pierre

[Frog]

And scum is usually visible on a new, clean, dry screen once one knows to look for a slight irridecent sheen.

[screenxpress]

I've had scumming in screens from not rinsing the screen good or not towel drying the water out the open area, what has work for me is spit believe it or not just wet my fingers and rub the area, crazy yeah but it works

yes, water will get it out as long as it's before you put ink on it. Once it's inked, water does not work . . .

pierre

I knew about the wonders of 'spit', but didn't know it can be done anytime before being inked.  When it has happened to me, I'm usually frantic to get it out before the screen has totally dried.  Tks.

[dirkdiggler]

Spit at ANYTIME here!  Even after its printed a while, doing it for years.

[blue moon]

Spit at ANYTIME here!  Even after its printed a while, doing it for years.

stand CORRECTED!!! I seem to remember different, but that's what happens when you are pushing the desk for few years.
Thanx guys.
Spit away!

pierre

[BRGtshirts]

Spit at ANYTIME here!  Even after its printed a while, doing it for years.

100% agreed. Spit works when mineral spirits won't no matter ink in the screen or not... tried to think about why that's the case once but it works so well I decided not to bother.. we find its the only thing for scum/water stains.

[Frog]

The few times that scum sneaks through, I usually just wet my finger with spit as well, though I've also been known to use Windex on a paper towel.
Sometimes, rubbing on both sides together really helps as well.

[mooseman]

Wow it could be scum and we never thought of that or tried spit but had thought about the application of, well another organic fluid, as this really pizzes me off when it happens.
Not new to this condition we do throughly rinse the screens after washout and inspect them with a back light looking for anything that would limit the use of the screen. The screens are wet at this point so possibly there is no visual at that point because the screen is still wet. I know we way over expose so that should not be an issue.
Have tried among other things windex, simple green, ammonia , white vinegar, chlorox tub and shower and a bunch of the usual screen business chemicals. The product shown is the only method that brings quick and positive results ??
I will go with scum as the culprit and inspect the screens dry just before ink from now on.
Thanks for all the good advise .
mooseman