# Problem double coating screen...



## aplusbowling (Dec 6, 2007)

Hello, maybe someone can shed some light for me...

When I try to double coat the garment side of my screen, it doesn't seem like any extra emulsion being left behind. I coat both sides once using a scoop coater and let it dry overnight. When I come back to coat a second time, I make sure the emulsion has dried thoroughly by feeling to make sure it isn't tacky. I run the scoop coater over the garment side to put a second layer of emulsion on, but it doesn't seem like any is going on. The emulsion has a "wet" look to it; but if I feel it, there doesn't seem to be any additional layers of emulsion. What am I doing wrong? Do I need to use the same technique when applying additional layers of emulsion as I do when applying the first layer?

Here's how I usually coat my screen...

-Use thin side of coater and start at the bottom and tip the coater so the emulsion flows up to the screen
-Tip coater back just a bit and pull it upwards leaving a nice smooth coat
-Turn screen around and repeat process
-For second coat after the screen dries, I do the same thing...but it seems like I'm just scraping of any emulsion that I'm trying to apply.

Sorry this is so long, but I'm at a loss here...


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## jpspent (May 29, 2008)

try coating the garment side one more time before allowing to dry.


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## aplusbowling (Dec 6, 2007)

So when you double coat a screen, you're supposed to do it BEFORE drying the first coat? I was under the impression you needed to let the first coat dry. I'll give it a try.


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## BEARBUBBLES (Aug 15, 2007)

correct when you coat your screen coat the first side, turn over coat the other side then let t dry over night or a couple of hours. good luck


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## jpspent (May 29, 2008)

I coat ,flip coat ,flip and coat one last time wet on wet. Let dry and your ready to expose. Seems to work for me on 100 to 10000 impressions.


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## aplusbowling (Dec 6, 2007)

I'm going to try what jpspent said. Anyone else have any input...?


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## TshirtStan (May 4, 2008)

aplusbowling said:


> I'm going to try what jpspent said. Anyone else have any input...?



Call me crazy...but I coat once on each side. Print side is coated last. Has worked 100% of the time. Go figure??


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## ukscreenprinter (Nov 18, 2007)

What you are looking for is the thickness of emulsion to be on the print /garment side.Start by coating the print side first,using two passes remembering to rotate the screen 180* after each coat(this allows the emulsion to bridge the mesh better giving sharper linework). Then repeat on the squegee side,again rotating the screen 180*,this pushes your emulsion through to the print side.Always dry horizontally,print side down.Unless you are looking for a really thick deposit of ink dry coating is pretty much unecessary.


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## RichardGreaves (Nov 7, 2006)

Mesh has holes in it, so emulsion always ends up on the other side! This is why it is standard procedure to finish coating from the inside, which pushes emulsion back to the bottom of the screen where it belongs. Use the rounded edge of the coater for the best filling action. In the web page below I have pictures of 6 coats with a sharp edge, and there is no effective increase in filling the holes with emulsion. Less emulsion means more 'waffle effect'. Dry the stencil with the inside up, so gravity can help pull the emulsion to the bottom of the screen.

Coating FAQ of Screen Making Products

Water in emulsion evaporates and leaves behind the solids. The stencil will always take on the shape of the mesh as it shrinks.









This makes for a poor gasket, ink can leak out of the grooves, but textiles are not as effected as smooth surfaces like glass. This is why so many people will be able to say "It works", without really explaining what you are doing. If you finish on the bottom side and scrape the bottom clean, pushing the emulsion into the mesh, you will have no emulsion on the bottom.









Face coating is used to fill these irregularities. This is where you use the sharp lip of the coater.
http://www.kiwo.com/Articles/Screen%20Coating%20Techniques.pdf


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## tpitman (Jul 30, 2007)

I can't say that I always do it, but you'll notice a big improvement in edge definition with a face coat after the initial coats have dried. I normally coat 2 coats on the shirt side from opposite ends, two coats on the squeegie side from opposite ends. If I add that face coat to, say, a 156 mesh, it eliminates any "stairstepping" in the stencil edges, yielding the detail of a 195 or 230 mesh but with more ink deposit if I need it.


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## aplusbowling (Dec 6, 2007)

Thanks for the replies...I took a blank screen and tried coating twice on the print side (1 pass, rotate 180 degrees then another pass), then I turned the screen over and repeated the process on the squeegee side. I can definitely tell that the emulsion is a little thicker. I've always used the sharp side of the coater, but for this I tried the rounder side.



> Face coating is used to fill these irregularities. This is where you use the sharp lip of the coater.
> http://www.kiwo.com/Articles/Screen%...Techniques.pdf


So, this is what I was seeing when I tried it before. Not much emulsion was being left behind because it was filling in the small irregularities in the screen left behind after the initial coats dried. It's all making sense now...


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## nearbrand (Jun 21, 2008)

Hi,

You need to re-coat it before the emulsion dries or you will not put andything onto the already dry emulsion 

I do, two coats one side (rotating 180 degrees after the first coat) and then two coats on the other side(rotating 180 degrees after the first coat) and then dry it laying flat (how it would be on the press) in the drying cabinet.

This causes gravity to pull the emulsion down and naturally create a thicker bottomed stencil.

Hope that helped.

Have fun!


Best Regards,

Matthew Riches
01473 399377


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