# Reclaiming screen using bleach



## prompt (Apr 20, 2006)

Hi! I'm new here, I've been doing silk screening or screen printing for just a month now, had my uncle teach me since he does that for a living.

I have a question though regarding reclaiming a screen:

I have tried using clorox as my 'reclaimer chemical' (since most of you recommended it) as I only use an unknown brand of emulsion bought here at my place (manila). The emulsion works great but after applying clorox or any bleach to the screen it just sticks and nothing happens, I sprayed it, blasted it with water, dipped it for minutes on a bleach but the stencil is still perfect.

Another question: What are the factors that can make the emulsion/stencil permanent on a screen? 

thanks!


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## fizz (Mar 4, 2006)

If your going down the bleach route then White vinegar will remove the emulsion.
You are best off with a proper stencil remover though.


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## JeridHill (Feb 8, 2006)

prompt said:


> Hi! I'm new here, I've been doing silk screening or screen printing for just a month now, had my uncle teach me since he does that for a living.
> 
> I have a question though regarding reclaiming a screen:
> 
> I have tried using clorox as my 'reclaimer chemical' (since most of you recommended it) as I only use an unknown brand of emulsion bought here at my place (manila). The emulsion works great but after applying clorox or any bleach to the screen it just sticks and nothing happens, I sprayed it, blasted it with water, dipped it for minutes on a bleach but the stencil is still perfect.


Maybe others know something I don't, but I have never heard of using Bleach to get rid of the emulsion on a screen. My guess is, if people are using bleach, they are trying to get stains out of screens.

There is a better way.

The first thing to know is, use the proper chemical for the job. It will make your life so much easier. I don't know what kind of access you have to screen printing supplies, but I imagine you can get everything you need.

You do want a good screen reclaimer (emulsion remover). The stuff I use is made by ICC and is biodegradable. When I spray it on, it takes literally seconds to dissolve the emulsion. One thing you would want to do is, spray it on and rub it with a brush of some sort. Do that to both sides and let is sit for a minute or two, (depending on what screen reclaimer you use).

Then use a pressure washer to spray out the rest. To get the stains off of the mesh, use a haze remover. They work extremely well.



prompt said:


> Another question: What are the factors that can make the emulsion/stencil permanent on a screen?


The main factor for the emulsion remaining on the screen is when you spray it with an emulsion reclaimer and you let it dry on the screen. Once it dries, it actually hardens the emulsion and a 3,000 psi pressure washer will get it off but it will still take at least 15 to 20 minutes to do it.


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## monkeylantern (Oct 16, 2005)

I've never used bleach....why not just use a proper emulsion remover? It's like using pizza sauce for ketchup....when you could as easily buy ketchup.


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## prompt (Apr 20, 2006)

Thanks for the replies. In my place, theres no branded emulsion like diazo and all those other stuff by speedball. They have these generic looking black plastic containers which contains pre-mixed emulsion (they also have that white emulsion stuff plus some orangy powder that you can mix yourself)

My uncle uses the same emulsion and the same reclaimer - bleach. and it's what he does as a business. I just don't know what I did wrong in the process of the bleaching thing. 

I know there are products specifically used for reclaiming but if you could save some bucks by using common household items then why not at least try it? this is my first time and just wanted to ask those who used bleach since I can't compare the chemicals I used to your chemicals.. 

thanks


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## Solmu (Aug 15, 2005)

prompt said:


> if you could save some bucks by using common household items then why not at least try it?


Because it won't necessarily be good for the environment or your own health.

When dealing with chemicals it's best not to take a 'try it and see' approach.


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## prompt (Apr 20, 2006)

Solmu said:


> Because it won't necessarily be good for the environment or your own health.
> 
> When dealing with chemicals it's best not to take a 'try it and see' approach.


I agree, but afaik, bleach is not a hazardous chemical (unless you drink it). I thought asking about bleach would work for me since asking what branded reclaimer to get may not work for me, as it may not be available here at our place. Might as well ask a chemical that everyone has, which in this case is bleach.

Thanks.


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## fizz (Mar 4, 2006)

Bleach works as a ghost/stain remover not an emulsion remover.
If you want household products as I said before vinegar works as it is an acid just like proper stencil remover.


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## JeridHill (Feb 8, 2006)

There is a company in Manila that carries Ulano products. Ulano makes emulsions, so they would have screen reclaimers. I'm not sure if they keept them in stock, but since they are distributors, theres a good chance. If not, they should be able to order them for you.

ENRIQUEZ (M.) ART SUPPLIES
1541-43 CM RECTO AVE. 
SANTA CRUZ, MANILA
P: (+63) 2 711 5158 - 61
F: (+63) 2 711 5158


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## prompt (Apr 20, 2006)

fizz said:


> Bleach works as a ghost/stain remover not an emulsion remover.
> If you want household products as I said before vinegar works as it is an acid just like proper stencil remover.


Thanks fizz!, I'll try that on my old screens.



DTG Printing said:


> There is a company in Manila that carries Ulano products. Ulano makes emulsions, so they would have screen reclaimers. I'm not sure if they keept them in stock, but since they are distributors, theres a good chance. If not, they should be able to order them for you.
> 
> ENRIQUEZ (M.) ART SUPPLIES
> 1541-43 CM RECTO AVE.
> ...


wow! thanks!


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## kurniad001 (Mar 3, 2009)

I think im three years late... but i use bleach to get the emulsion off my screens.. I rub it on with a toothbrush, and leave it for an hour or so and rinse it off with a power washer... i only do this because I cannot afford the commercial stuff... but as soon as i get some money coming in i will probably go for something thats better for my skin.


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## ino (Jan 23, 2007)

kurniad001 said:


> I think im three years late... but i use bleach to get the emulsion off my screens.. I rub it on with a toothbrush, and leave it for an hour or so and rinse it off with a power washer... i only do this because I cannot afford the commercial stuff... but as soon as i get some money coming in i will probably go for something thats better for my skin.


 Wouldn't a toothbrush be a little bit on the small side to brush a screen? i'm sure a dish washing brush would be more suitable.


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## drunkswithapress (Jan 15, 2009)

I use Ulano QTX emulsion and i also use bleach to reclaim my screens, i haven't had a problem so far. I'm not a professional as i reclaim my screens in my bathtub,burn them in my basement and print in my daughters room. The process i use in short form is this
Clean off the excess ink with mineral spirits.
Pour some bleach on one side of the screen and let it soak for 5-10 minutes.
Scrub with a soft bristle brush NOT WIRE brush. the same kind of brush you would use to scrub your bathroom. 
Repeat on otherside of screen.
Repeat process until emulsion is gone.
Spraying with hot water doesn't hurt either.

I've heard that letting the bleach dry will lock in the emulsion, as is, with other emulsion removers.
hope this helps...


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## RichardGreaves (Nov 7, 2006)

Water or solvent resistance of a stencil depends on the complete cross-linking of the ingredients by the sensitizer with UV energy. If the exposure time is too short, or UV energy doesn't move all the way through the stencil, the cross-linking is incomplete, and complete resistance isn't achieved.

UV energy reacts with diazo or photopolymer sensitizer in the stencil and causes a chemical cross-link between the two components that make up the "emulsion". Linked together, and woven in and out of your mesh, the exposed/cured/hardened stencil will not dissolve with water and rinse own the drain.

Industrial stencil removers use Sodium MetaPeriodate (SMP, CAS 7790-28-5), to attack these cross-links, releasing breaking down the stencil so it will dissolve, and you can reclaim the mesh and coat it again.

If you let this "soup' of stencil remover & emulsion dry on the mesh before you can rinse them down the drain, they form a new chemical bond that is permanent. There is no chemical to break down this chemical combination except the brute force of water pressure. Yes you will also lose mesh tension blasting the mesh as it vibrates like a drum, if the stencil doesn't come out. If you use 3,000 psi water, you don't even need a chemical to breakdown your stencil, but it helps to have tight mesh to resist the pulsing water from a pressure washer.

This this hard to reclaim effect also happens with *under-exposed stencils*. No cross-links - hard to reclaim.

A stencil may have worked OK with harmless plastisol, but if you clean the ink with a strong solvent, the solvent can attack the defenseless under-exposed stencil and *chemically bond it to the mesh *that only a razor blade can fix.


Bleach _is used _to remove *gelatin indirect stencils*, but bleach is inferior to SMP for breaking UV cross-linked diazo or SBQ. It takes more bleach to do the work of a small amount of SMP. 

Many will answer, "but it works", this is a classic do you have time or money question. 

When you go home I want you to use a key to open your front door, not the kick of brute force.


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## ka26det (Sep 11, 2009)

I've used bleach before...it just took longer to clean...but i did do the job. just make sure you use 1 part water 1 part bleach (or at least that's what i heard)


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## bjohn13 (Dec 6, 2009)

i've used soft scrub with bleach to print on black shirts and it has never taken off my emulsion. new here by the way and i think you all rock.


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## jsf (Aug 4, 2009)

prompt said:


> Hi! I'm new here, I've been doing silk screening or screen printing for just a month now, had my uncle teach me since he does that for a living.
> 
> I have a question though regarding reclaiming a screen:
> 
> ...


Hi Rom, applying Photo Hardener will make the emulsion permanent on screen. And still you can reclaim this using bleach (time consuming) or a chemical removing emulsions with hardener like fotochem.

Should your screens not applied by P-hardener, it can be easily removed by using a 'stencil remover' (pioneer and multi-print have this).

More information with regards to your problem is in this previous post: http://www.t-shirtforums.com/asia/t97255.html

Goodluck.


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## LoneTurtle (Nov 19, 2010)

prompt said:


> Thanks for the replies. In my place, theres no branded emulsion like diazo and all those other stuff by speedball. They have these generic looking black plastic containers which contains pre-mixed emulsion (they also have that white emulsion stuff plus some orangy powder that you can mix yourself)
> 
> My uncle uses the same emulsion and the same reclaimer - bleach. and it's what he does as a business. I just don't know what I did wrong in the process of the bleaching thing.
> 
> ...


I did my share of screenprinting on a shoe-string a few years back and I am familiar with using bleach as a reclaimer. Not very effective. If you want an effective non-brand cleaner, you'll need something like caustic soda, which was what I always used. But be VERY careful and, ideally, do it outside (don't wash screens in the bath as the caustic soda will roughen the bath surface). This is only safe to use on synthetic fabrics as it will dissolve cotton organdies. Using a nylon bristle brush, paint a solution of caustic soda on both sides of the mesh and leave for 20 minutes or so. Then hose out and rinse thoroughly. Caustic soda is also an effective degreaser in weaker solutions. Make sure you wear rubber gloves, eye protection and old clothes!!

The "orangy powder" you refer to is Potassium Dichromate. I used to buy this from chemists (pharmacies) back in the days when raw chemicals were sold over the counter. I made my own emulsion with gelatine and potassium dichromate. It works but it is a very inferior emulsion compared to the brand types that are now available. Also, it had to be sealed by painting the inside if the stencil with shellac and clearing the open areas by washing the underside of the mesh with a rag soaked in meths. A very messy, smelly, dangerous and time-consuming process.

I echo the advice of others in this thread: Use branded products.


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## tpitman (Jul 30, 2007)

For the life of me I don't understand why people keep trying to save a buck on poor chemistry choices. Reclaimer comes in three varieties: the watered-down, ready to use stuff, the concentrate that you mix about 20 parts water to one part chemical, and the crystals. The concentrate is by far the most convenient and the price is modest for what it does in terms of effectiveness and convenience. I also understand that we here in the states have more resources for products, but most of the countries from which some post are not exactly some backwater. You might not have access to the flood of product we spoiled Americans have, but I'm sure there are manufacturer's represented there that offer professional products that will go a long way to making your job more efficient and safer for your health. There are some things you simply have to crack you wallet for. You can build a serviceable washout booth or exposure unit, and in some instances a decent press, especially some of the line table presses I've seen posted here, but spend money on good mesh, emulsion, frames, chemistry and ink. Those are all the parts that image the shirt, and that's what you're selling.


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## lben (Jun 3, 2008)

I realize this post is old, but for the person who said bleach was safe unless swallowed was wrong. The gas given off from chlorine bleach is deadly when concentrated in a small area. Even small amounts of this gas can affect your health. If you are going to use bleach, just make sure you do so in an open area where you will have plenty of fresh air to breathe. Also remember that you have to be careful not to use other chemicals that could react with the bleach.


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## LoneTurtle (Nov 19, 2010)

For the life of me I don't understand why people keep trying to save a buck on poor chemistry choices. Reclaimer comes in three varieties: the watered-down, ready to use stuff, the concentrate that you mix about 20 parts water to one part chemical, and the crystals. The concentrate is by far the most convenient and the price is modest for what it does in terms of effectiveness and convenience. I also understand that we here in the states have more resources for products, but most of the countries from which some post are not exactly some backwater. You might not have access to the flood of product we spoiled Americans have, but I'm sure there are manufacturer's represented there that offer professional products that will go a long way to making your job more efficient and safer for your health. There are some things you simply have to crack you wallet for. You can build a serviceable washout booth or exposure unit, and in some instances a decent press, especially some of the line table presses I've seen posted here, but spend money on good mesh, emulsion, frames, chemistry and ink. Those are all the parts that image the shirt, and that's what you're selling. 

I have to agree here. When I started out screen printing back in the 70s, the only branded materials available in the UK were supplied to printing companies and only available in bulk. For the "hobbies" market, there was Profilm, small jars of cheap "screen printing dye" and little squeegees that were marginally better than the kind for cleaning windows. If you wanted to take it seriously but were not in the industry, you had to improvise.

Today, there is a whole range of materials available in one-unit quantities. In the UK, there are very few areas where screen printing equipment and materials can be bought locally... but the wheel was invented a long time ago. Use it and venture beyond the corner store. There is an abundance of everything you'll need available at the click of a mouse, if travelling is not an option.

There is a certain appeal in improvisation and I still like to make my own frames, presses, stretching devices and so on. It's fun and the fact that most of the equipment can be made at home is part of the charm of screen printing. But _materials_ are another matter. Do-It-Yourself chemicals are dangerous and very inferior to products manufactured to professional standards. Screen cleaners are very dodgy chemicals to mess around with and you need something that has been manufactured with health and safety in mind. When I made my own emulsions, it meant that I had a can of _potassium dichromate_ in the house. That stuff becomes an explosive in high concentrations once moisture has been allowed to get into the can. Not the stuff you want to store in the cupboard under the sink.

It's not only unnecessary, it's dangerous.


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## LoneTurtle (Nov 19, 2010)

jsf said:


> Hi Rom, applying Photo Hardener will make the emulsion permanent on screen. And still you can reclaim this using bleach (time consuming) or a chemical removing emulsions with hardener like fotochem.
> 
> Should your screens not applied by P-hardener, it can be easily removed by using a 'stencil remover' (pioneer and multi-print have this).
> 
> ...


Thanks for the advice, J. But there's an identity mix up here. I'm not the one asking the question. I did my share of improvised chemistry when I started out. I stick to the branded products now. Much safer.


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## jsf (Aug 4, 2009)

LoneTurtle said:


> Thanks for the advice, J. But there's an identity mix up here. I'm not the one asking the question. I did my share of improvised chemistry when I started out. I stick to the branded products now. Much safer.


Such an old post. But there is no mixed up please backread. The OP's name is Rom and you are Ron.  I did type it Rom and not Ron.


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## LoneTurtle (Nov 19, 2010)

jsf said:


> Such an old post. But there is no mixed up please backread. The OP's name is Rom and you are Ron.  I did type it Rom and not Ron.


Sorry J. My error. I was assuming it was a typo without checking. I stand corrected.


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## jsf (Aug 4, 2009)

LoneTurtle said:


> Sorry J. My error. I was assuming it was a typo without checking. I stand corrected.


No problem at all, Sir Ron. 

Welcome to Forums.


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## bahttat (Mar 12, 2011)

do any of you guys soak the screens in emulsion remover because i inherited a dozens screens that are really blocked


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## Bob Wellen (Jan 25, 2011)

Guys, I am probably too old but bleach used to be used to remove transfer films back in the day. Use an appropriate emulsion remover and haze remover for ink and emulsion haze left behind. generally the reclaiming basic ingrediant is metaperiodate. It is imoritant to reclaim properly so the next stencile will adhere to the screen correctly when exposed.


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## RichardGreaves (Nov 7, 2006)

*Soaking old screens in stencil remover*



bahttat said:


> do any of you guys soak the screens in emulsion remover because i inherited a dozens screens that are really blocked


If the mesh is to be reclaimed, the stencil must be made water-soluble, or at least water-softened, so that it can be blasted from the screen with water pressure.

*Stencil remover attacks sensitizer cross-links*
Stencil removal chemicals are *water-based* so the stencil is designed to resist penetration from them. Water resistant stencils are even more resistant - by design.

*Ready-To-Use Stencil Remover Advantage*
The HUGE advantage of more expensive pre-mixed stencil remover (over concentrated mixes where you add your own water), is there is also a wetting agent in the ready-to-use that can't be concentrated.

The wetting agent helps the water-based stencil remover penetrate into the water resistant stencil. If you're having good luck with concentrate mixes, GOOD, don't change, but everybody should have some RTU in case you have a difficult screen - or want a stencil remover that works faster.

*Sensitizer Cross-links*
Water or solvent resistance of a stencil depends on the *complete* cross-linking of the ingredients by the sensitizer with UV energy. UV energy reacts with diazo or photopolymer *sensitizer *in the stencil and causes a chemical cross-link between the two components that make up the "emulsion".

If the exposure time is too short, there are* fewer cross-links to break* and the emulsion will be very difficult to dissolve. No cross-links = hard to reclaim.

More exposure means, more, or hopefully, complete exposure/curing/hardening/cross-linking of the stencil. If you add even more exposure - you waste time, lamp life and electricity, but it won't hamper stencil removal. You my get a under cut, light scattered, choked image, but it will reclaim like a dream. It's counter intuitive - I know.

You're stuck with the mystery stencils you inherited and it seems like you tried to reclaim already with poor success.

*Don't let stencil remover dry*
Soaking may help, but don't let the stencil remover dry. If you let this 'soup' of stencil remover, broken cross-links & emulsion dry on the mesh before you can rinse them down the drain, they form *a new chemical bond that's permanent.*

There is no chemical to break down this new chemical combination except the brute force of water pressure. 

*Hydro Blaster*
Hydro Engineering of Salt Lake City, Utah taught the world to use 3,000 psi water and *no chemicals* on a tight screen. You don't need a chemical to breakdown your stencil, but it helps to have tight mesh to resist the pulsing water from a pressure washer.

Your local car wash will have a pressure washer of some sort but don't get caught leaving a mess.


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