# burning the image to the emulsion using Yudu



## lyricalgenius (Jan 29, 2010)

Hello I have a yudu and I cant seem to get my emulsion to come out right it always ripples or cracks. And the plastic part that you take off i cant seem to get it off without pulling the emulsion off can any1 tell me what im doing wrong ? thanks and how to print for image overlapping with the yudu


----------



## PositiveDave (Dec 1, 2008)

You might not be drying the film properly.


----------



## RichardGreaves (Nov 7, 2006)

Training videos of direct film & emulsion coating and exposure:

"How Does Capillary Film Work" video 95 Mb 17 minutes
"How Does Direct Emulsion Work" video 105 Mb 19 minutes


----------



## editornoliver (Jan 19, 2010)

make sure you wet the screen first then put the film on there and squeege the film. 

Then make sure its all the way dry before you pull the plastic off. The dryer it comes with is crap and you will need to at least let it dry a hour or two before you should try to remove the plastic.


----------



## lyricalgenius (Jan 29, 2010)

Can I put too much water on there?


----------



## RichardGreaves (Nov 7, 2006)

*Coating mesh with capillary film*



lyricalgenius said:


> Can I put too much water on there?


Capillary films are effected by the amount of water used to wet the mesh, the choice of mesh and film thickness and how the mesh was prepared. 

I count to ten after I *'pour'* water on the mesh with a large plastic cup or bucket and the water stops 'rippling'. I if can't apply the film before ten, I start over. 

Counting to ten standardizes my procedure and helps everyone in the shop produce the same stencil.


----------



## spencersgrl (Jan 1, 2011)

when you apply the emulsion sheet, make sure your screen isn't dripping wet. when drying, leave the door open and let a fan blow air in there as well. I usually let mine dry for about 15 minutes inside then take it out and let the fan blow directly on it for about five minutes. I then have no problem pulling the sheet off. when you start to pull it off and you meet resistance, it is because parts of it isn't dry, you need to either put it back in or set it in front of the fan. good luck


----------



## ramdisk (Sep 7, 2010)

I tried the cap film emulsion sheets and had nothing but trouble! I have since switched to using diazo emulsion. Speedball has some that you can get at hobby lobby with a coupon! I have found that it is MUCH more economical than using the yudu cap sheets. It can be a little bit messier until you get the hang of it. Let me know if you want/need more info. 

Nick


----------



## RichardGreaves (Nov 7, 2006)

*Coating mesh with direct film*

You don't describe why direct film is "nothing but trouble", but if you think why your film isn't working - that always points to a process solution. *IF* a small piece doesn't dissolve in water, the actual film should be rejected.

Direct film (capillary film), is direct emulsion coated on polyester backing at the factory. You attach the film directly to the mesh before you expose it.

ALL films need a solvent to *soften them* (dissolve them a little), so they will stick, dry and adhere to the bottom of mesh. 

Because direct film has a 95% solids content compared to direct emulsion that has only 25-48% solids content you get faster drying and an ultra smooth surface all on the bottom of the mesh.

Of course, the convenience of direct film costs just as raw food cost less than prepared food.

Unless you're printing water-based inks and need the resistance provides, you will expose faster with a presensitized direct emulsion that has an 18 month shelf life.

Diazo sensitizer isn't as fresh 4-6 weeks after you add it to your emulsion. It still works, just not at the same speed as when it was fresh.

Please let us know where you found a Hobby Lobby coupon.


----------



## ramdisk (Sep 7, 2010)

My main trouble with the cap film I think probably comes from the fact that as a person very new to hobby screen printing (hence the yudu) I had a very difficult time once the film was wet, per the instructions provided by YUDU, getting it to stick to the yudu screens without bubbles, and some areas released the hold on the cap film. Some of this I think probably has to do with the fact that the YUDU brand film is probably some of the cheapest cap film sold at a premium price. I am not sure if you have had any experience with the YUDU brand films, but I am sure if I had purchased pro quality film I would not have had as much trouble. The reason I went diazo was because it was readily available to me and my only other option without having to go mail order.

If you "friend" hobby lobby on facebook, or go to their website you can sign up for email from them and every week send a new coupon. Usually 2 or 3 times a month this is a 40% coupon.


----------



## RichardGreaves (Nov 7, 2006)

ramdisk said:


> My main trouble with the cap film I think probably comes from the fact that as a person very new to hobby screen printing (hence the yudu)
> 
> I had a very difficult time once the film was wet, per the instructions provided by YUDU, getting it to stick to the yudu screens without bubbles, and some areas released the hold on the cap film.
> 
> ...


OK. The water that's held in the mesh should soften the film and it will be sticky. If you need it, a window squeegee can gently bring the film in contact with the wet mesh.

Even film smashed into contact with the mesh will deliver a better stencil in less time than direct emulsion.

You have several film distributors nearby. 

Check these film manufacturers for distributors:
autotype.com
chromaline.com
murakami.com
ulano.com


----------



## selanac (Jan 8, 2007)

I know you're only doing hobby work, but I'd invest in a screen printing class and learn to do it right. 

Ryonet goes through every aspect of screen printing, and you practice practice practice. 

Oh, and did I mention Practice.


----------

