# Millions of pinholes! Is it from a dirty screen or poor coating techniques?



## Catierules (Jul 15, 2012)

Main causes of pinholes?

I work in a shop that recently lost its manager and with her the knowledge of how we were reclaiming, coating and burning screens. Its been a few weeks and we have gotten the reclaiming part down we think. Because we were noticing chemical streaks after we coated the screens, these streaks would wash out or break down quickly but the rest of the screen area was ok. Now the screens are cleaner but once it gets burned and washed out we get major pinholes after the first couple strokes of a squeegee. So many pinholes we have to re burn a new screen.

My co worker is convinced its still the reclaiming process. That the screens are still greasy so the emulsion is not sticking in places. Our process is this; reclaim emulsion from screen, rinse and dry, de haze screen, rinse and dry.
We have also tried degreaser, acetone, and bleach with the other two process. All of these seem to get the screens clean.

So I am thinking its how we are coating the screen.

As a side note we use vellum art stencils so we are also suffering from the middle of our images not washing out, making us have to scrub them(just the image not any of the surrounding emulsion). We know getting a better art printer is going to make everything easier, but we gotta wait on the big bosses for that one. And before the manager left she was using the same art and burn time as now with much fewer washout and pinhole problems.

I think we need to use more coats of emulsion or burn at a lower ltu so we are not keeping the screen wet for so long while we try to scrub out the art. We are coating the screen once on the tee shirt side and twice on the squeegee side. Then they dry for at least 24 hours. We have an appropriate dark room but it lacks in much temperature/ moisture control.
After coating I can hold the screen up to the light and in places, mostly the top and bottom of the screen I can see tiny....bubbles....dirt...pinholes? I dont know if the screens always looked like that and just held up better or if all those tiny tiny dots are going to turn into pinholes? Are we coating too fast or thinly that we are trapping bubbles? There are some little bubbles in the emulsion after Im pour it into the coater. But I cant seem to make them pop quickly and you cant really let that stuff sit out uncovered right?

Right now we are fixative spraying or re heating the vellum art when possible to make it darker until we can get a better printer. So spary out time should shorten. What is the best amount of time for the screen to be wet while you wash out?

Thanks for reading all my questions. Please help if you can. Do you think its a reclaiming/ dirty screen problem or a coating/burning/washing problem?

Thanks again!

Catie
Knowledgeable printer, novice screen coater.


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## TshirtStan (May 4, 2008)

Pinholes, in my experience- come from the screens not being clean. I have aa few issues occasionally with the chemical streaks still. I make sure I flush the screens for several seconds once I am done recalling then place them aside. If you have a fan blowing while drying and someone walks behind it.... Dust and dirt can get on the screen. Gotta be careful. My reclaimed and dried screens I store in a garbage bag until I coat them to keep dust off too.


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## Celtic (Feb 19, 2008)

Yes, I agree that it's a combination of you must degrease the screens, completely and then fully rinse them out. Stick to using actual degreaser. 
I do think that the chemicals are not getting throroughly rinsed out. 
This will definitely cause big issues, as you've found out. 
Dry/store in a clean area. 
Also, be sure that the emulsion is done in a clean area. Debris could be blowing in at this time too.


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## inkdrips (Aug 16, 2010)

How are you drying? When I started, I tried drying with a cloth, but it left lint in the screen. You couldn't see it till you burned the screen. Then it was pinhole city. Make sure you degrease. Even if it is with dawn blue and water. Just scrub it well. Not hard, well. 

Sent from my ADR6400L using T-Shirt Forums


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## beanie357 (Mar 27, 2011)

Millions indicates possible multiple issues.
Franmar has vids on YouTube.
Do not use the incorrect chems.
Also, if mixing or stirring ur emulsion wrong you will introduce bubbles.
Dust while drying also a no no.
Watch some vids, andvreasses your procedure from step 1.


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## foot print (Jun 2, 2010)

I think it's a coating issue. I coat my screens ink side / print / ink side and I get very few pin holes in any at all. Also make sure your glass is clean.


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## ScreenFoo (Aug 9, 2011)

If you're not using one, get an exposure calculator--a bunch of pinholes probably equals putting way more emulsion down than the last person when you coat, resulting in underexposure at the same time, and pinholes. Your co-worker saying they're "greasy" because the emulsion doesn't stick would support this--if it's properly exposed emulsion, it will encapsulate the grease and still hold on.

Not to say prep isn't critical--some residual chemicals or dirt in the right spot will make pinholes.


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## 2020 PrintWorks (Apr 22, 2011)

The only time i every get lots of pinholes like your describing is when the glass is really dirty or I'm using a really low mesh screen that wasn't coated well enough. Pinholes shouldn't just appear when you start printing either. They would already be there. You could always double up your positives until you can get a better type of film. I feel your pain. Vellum sucks ***. If worse comes to worse just take a credit card or something and after the screen is burned and dry apply a thin layer of emusion to the print side to get rid of the pin holes. Just don't cover over your already hosed out image. Then let that dry and expose the screen again to harden the new layer. A place I worked at before did that to every screen just to avoid break downs during long runs on the auto.


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## 2020 PrintWorks (Apr 22, 2011)

Not sure if I'm correct in saying "print side". I mean the side of the screen that faces down when your printing.


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## CoryJacksonville (Jul 6, 2015)

I think you need to go back to the Emulsion and first make sure it is prepared correctly. Is it an Emulsion that is already mixed and ready to go? Or do you have to add water to a bottle mix and then add to Emulsion dump in Emulsion stir in well and let sit a few hours before you coat? I think your problem is your sensitizer isn't mixed well and then added to the Emulsion improperly! That is where you need to start. Make sure it is mixed well try using bottled Distilled water instead of Tap Water. Mix Very Well! Let sit Over Night to let out all air bubbles. Then coat good clean screen. You really shouldn't have to be degassing a lot on screens especially if they are cleaned fairly quickly. Just use your Ink Degrader!

Also on your Vellum Films instead of heating them? Don't you lose registration on multicolor jobs? Try using a Spray Can Darkener or fixative its kinda like hair spray. Spray on new Vellums let air Dry and it will considerably darken your Art Work.

Cory in Jacksonville Florida


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## lvprinting (Sep 23, 2014)

Dry with a dehumidifier, not a fan.

But for your issue, it's likely that your screen was not prepped properly because you didn't degrease it or rinse it well and the emulsion wasn't able to adhere properly.


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## CoryJacksonville (Jul 6, 2015)

True you want your screens really clean and Degreased. Chromaline has a newer product called I think Screen 260 that is a 3 in 1 product it is supposed to Ink Degrade, De-haze, and Degrease all in one! that sounds awesome and from the reviews really works well! Make sure your screens are clean and dry, your Emulsion is prepared (try use a already prepared Emulsion with higher solids probably the pink one), and properly coat your screens. After that make sure they are exposed properly. Try using an Exposure Calculator if you don't or can't buy one you can download a version online and print it out on film. Find out what your exposure time should be and go from there. Sounds like you are fighting and uphill battle, but it can be done!


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## ScreenFoo (Aug 9, 2011)

Re-reading this I should have added fisheyes... also very common with contamination.
Still shoot screens with dust and contaminates that develop and print just fine though...

FWIW, I think we scared off the OP a few years ago...


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## sben763 (May 17, 2009)

ScreenFoo said:


> Re-reading this I should have added fisheyes... also very common with contamination.
> Still shoot screens with dust and contaminates that develop and print just fine though...
> 
> FWIW, I think we scared off the OP a few years ago...


OP hasn't signed in since July 31 2012. 

Tyson just got back from Colorado last week in June. Spent 7 days driving around looking at waterfalls. With all the May snow showers about every waterfall was active. Best trip to Colorado ever. Still haven't made it to the northern part of the state. Maybe next trip.


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## ScreenFoo (Aug 9, 2011)

sben763 said:


> OP hasn't signed in since July 31 2012.
> 
> Tyson just got back from Colorado last week in June. Spent 7 days driving around looking at waterfalls. With all the May snow showers about every waterfall was active. Best trip to Colorado ever. Still haven't made it to the northern part of the state. Maybe next trip.


I'm torn on the precip.
Waterfalls are always cool, but wet trails get closed. 
What a conundrum.


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