# can't wash stubborn emulsion. what am i doing wrong?



## alzek114 (Jun 16, 2009)

hi there. im new in silkscreening and im already hitting the walls. i have tried so many times washing the emulsion off the screen but it won't come off at all! here's how it goes. i have already dried the emulsion in a dark room, having a fan to dry it off. since im new, i tried letters first. i sandwiched my opaque letters between the silkscreen and the sheet of glass and let it sit out under the sun for 1 minute. when i disassembled the setup the unexposed part can be visiby seen(which is supposed to be washed off). I tried to wash it off with a pressurized hose in the bathroom. And here comes the problem. The design part won't come off! so i tried the second time. this time i did not expose the setup to the sun but just simply coat the sceen with the emulsion, let it dry and wash it off.same result! but of course since it was not exposed, it was somehow easier to wash off,but not that easier,it still was hard!please help me i don't know what to do anymore!btw im using commercialized emulsion.i saw the tshirts of my supplier and it was ok.they use the same emulsion.when you mix the sensitizer with the emulsion it becomes yellow in color.


----------



## pukingdeserthobo (Jun 3, 2008)

try cutting your time the sun is pretty powerful you dont need to expose long, also u might look in on getting a pressure washer


----------



## out da box (May 1, 2007)

Are your screens seeing light before you expose them? What kind and brand of emulsion are you using? Make sure the glass is extremely tight to the screen and positive- allow no light to get between your image and your screen.
The emulsion should definently wash out if you haven't exposed it.


----------



## alzek114 (Jun 16, 2009)

out da box said:


> Are your screens seeing light before you expose them? What kind and brand of emulsion are you using? Make sure the glass is extremely tight to the screen and positive- allow no light to get between your image and your screen.
> The emulsion should definently wash out if you haven't exposed it.


well my screen only sees normal lighting after i get it out of the dark room.i'll ask my supplier about the emulsion.yes, it's tight alright(the glass).

@pukingdeserthobo. okay i'll cut the time.but the bigger issue at the moment would be the unexposed screen not being completely washed out after trying to get rid of the emulsion.i saw bre of makemagazine and matt of etsy on youtube.they only used a garden hose,which has pretty much the same psi as mine.they did ok, i didn't.


----------



## Solmu (Aug 15, 2005)

Garden hose _can_ work, but pressure washer is *much* better for reclaiming. As soon as you run into problems, a garden hose doesn't cut it.


----------



## bv805 (Dec 25, 2008)

It almost sounds like your emulsion is bad i cant imagine you over exposed it by being out for one minute, pressure washer can help but watch out it will start to degrade the emulsion if you blast it to long, you should look into a homemade exposure unit


----------



## mrvixx (Jan 13, 2009)

Solmu said:


> Garden hose _can_ work, but pressure washer is *much* better for reclaiming. As soon as you run into problems, a garden hose doesn't cut it.


I think he is washing out the image not reclaiming the screen.


----------



## pukingdeserthobo (Jun 3, 2008)

alzek114 said:


> well my screen only sees normal lighting after i get it out of the dark room.


what do you mean normal light? ones it starts hitting light it starts exposing


----------



## alzek114 (Jun 16, 2009)

pukingdeserthobo said:


> what do you mean normal light? ones it starts hitting light it starts exposing


normal light like the sun provides inside the house but just a little bit brighter, thats all. when you said once it starts hitting light,do you mean any type of light source? oh, i think i know the problem.because of what you said, will i also assemble the setup inside the dark room or is it okay to do it outside the dark room?


----------



## wendy1909 (Jul 5, 2011)

I have been having this same problem. I recently started using a home-made light box with 4 20w fluorescent bulbs for total of 80 watts. I tried 45 mins., then 1 hr 20 min., then just 20 min. None of them worked. I'm using Diazo emulsion which was only sensitized a week to a week and a half ago. I'm using white Speedball screens but not sure what mesh count. Today I tried using the sun for 42 min. and that didn't work either, though it did melt the ink onto the glass from my transparency so it would've been unusable anyway. I'm using a piece of styrofoam to press the screen against my transparency and through my trials to rinse it out I have given it time to soak...is that not good enough? I will try getting a bug light and using thicker emulsion, though I was taught in the past to use one thin coat. Thanks and anymore help is welcome. I read that if it's overexposed more than you want washes out, and if it's underexposed it doesn't wash out, but as you can see I've used very long timing.


----------



## Lubus (Oct 4, 2011)

emulsion remover, degreaser?


----------



## wendy1909 (Jul 5, 2011)

My remover is Diazo and degreaser is Purple Power, but I'm just trying to rinse out the image.


----------



## happyprint (Sep 29, 2011)

few week a go i have that's problem too.. i think that's emulsion problem.i think i buy expired emulsion. 

try this trick: use a bleach to screen


----------



## Tj Ryonet Tech (Jul 28, 2008)

If the emulsion is stuck don't use bleach. It is unpredictable and will short the life span of the fibers in your screen. Take the screen to an outdoor car wash or something similar with a high pressure hose and "muscle" the emulsion out at that point.

As for the light issue- you need to be coating and drying in a light safe environment. Put a yellow bug light in your bathroom or darkroom and keep the screens in there until you are ready to expose. Currently you are pre-exposing the screens and thus they are over-exposed.


----------



## happyprint (Sep 29, 2011)

@ Tj Ryonet Tech
yes bleach unpredictable..
in my emulsion problem.. say i am pre-exposing the screen,
but why i can't remove it?.. even before i burn it..

i was thought i use expired emulsion,it's true? i use sintisizer emulsion.

sorry i am newbie


----------



## wendy1909 (Jul 5, 2011)

Ok thanks I was coating with lights off away from sunlight and then placing it inside a closed cabinet, but I guess that may still be too much light?


----------



## Alan Buffington (Oct 27, 2010)

Some notes from an emulsion manufacturer.

1. As mentioned coat in a light safe environment. Only yellow safety lights, bug lights are ok. No light coming in from any doorway or window from the outside or white fluorescent lamps.
2. When you expose outside you must bring your entire set up inside to the light safe area before removing the screen. If you have no sink in this area you can sponge on water from a 5 gallon bucket and remove the image. Any light outside from the sky or reflecting off a building will expose your image instantly.
3. run a step test. Go to w w w murakamiscreen dot com for instructions on 'step test to determine exposure time'.
4. Use black t-shirt material on inside of screen to prevent light from bouncing off white foam and causing exposure in your image.
5. Always store coated screens in a light safe area. Once the emulsion is dry use black trash bags. Coat at night, put in black trash bags for use in the daytime.
6. Use commercial emulsion removers. If your screen won't reclaim with them you may be using an SBQ emulsion that has been underexposed and cleaned with screen opener, mineral spirits, or hot solvents that are flashing the emulsion. Post expose in sun or 2x original exposure time on a light table before printing, this will create a more reclaimable screen.
7. Coating: 1:1 minimally, less is better on fluo tube exposure systems. Avoid thick stencils on weak exposure systems. Typically we see fluo systems in the 12-19 minute range for good exposures using a dual cure or diazo emulsion.
8. During development rub a white rag on a wet non imaged area on the squeegee side of screen. If you see emulsion color you are probably underexposing your emulsion. Avoid underexposing, you will only create pinholes and a weak screen and wash off the emulsion you paid for.

Alan Buffington
Murakami Screen USA
800-562-3534


----------



## Tj Ryonet Tech (Jul 28, 2008)

Are you using an emulsion remover when trying to reclaim? Water alone is not going to take off emulsion. Pre-exposing is burning so to speak. You have already started the process with pre-exposure. Sensitizers cross-link when exposed to UV energy, which makes the stencil insoluble. Stencil remover chemically breaks the cross-links. 
Expired emulsions can have unpredictable results as well. It could be you can't get a good exposure, it could be you get an exposure but can't reclaim effectively. If you think the emulsion is expired get new stuff and save yourself a lot of hassle.


----------



## Alan Buffington (Oct 27, 2010)

TJ has a good point here. You may have a diazo or dual cure emulsion that has expired. Diazo based emulsions are only good for about 4-6 weeks, a little longer if you keep them at 60-72 degrees. Once they have sat in heat over 90 degrees they can go bad quickly, same for coated screens. SBQ pure photopolymers are unaffected by heat and have a long shelf life. As long as no diazo is added they are good for a year, coated screens 6 months in a light safe storage area.

If you have doubts about your storage area place some coins on the screen and allow it to sit for 24hrs.
Develop the screen as if it were exposed. If you see the circles from the coins wash out of the screen before the rest of the emulsion you have light in your storage area that is slowly exposing your screens.

Alan Buffington
Murakami Screen USA
800-562-3534
call anytime


----------



## happyprint (Sep 29, 2011)

i use bleach for reclaim..
yes i think my emusion expired.. i buy new one with same brand but in different store..and i don't have no problem for expose and reclaim.
i reclaim my expired emulsion with mineral spirit like notes from Alan Buffington..

yes i never think about it..pre- exposed it is burn the screen.

this forum fantastic! you all rules..


----------



## Alan Buffington (Oct 27, 2010)

While you can get bleach to work, it works nowhere near as well as commercial screen reclaimer and the large white dots on my jeans bum me out.


----------

