# Locked in emulsion...a fix (at least for me)



## TurboSi (Jul 2, 2009)

I recently bought out a small screen printing business. With the pile of screens was a dozen locked in screens of various mesh. Most of them appeared to be DXP dual cure and some were the blue emulsion. All of them had the reclaim process started and then left to dry and were really locked in.

I tried soaking them in emulsion remover, tried bleach...heck I even tried paint stripper, acetone, laquer thinner, just about anything I could find. I threw the bad screens in a corner and forgot about them. I even did some searching on the net and in this forum but only found info on how NOT to get into locked in emulsion messes.

A few weeks later I was burning some screens for a job the next day and had issues. The last owners never pressure washed the screens and they were hazed to badly to burn well. I also had run out of de-hazer the day before and wasn't sure what I was going to do...then I had an inspired thought. De-hazer is basically just lye and I had a bottle of drain cleaner, again, basically lye.

I coated the screens and saw the locked in ones in the corner. Just for fun I spread it on one of them and let them sit for 20 or so minutes. I was able to de-haze the screens and when I got to the locked in one it started to clean up!
The next day I grabbed another locked in screen, coated it liberally with the drain cleaner and let it dwell for 40 minutes. I hit it with the small pressure washer and the emulsion came out fairly easy. To make sure it wasn't a fluke I did another 5 screens, 40 minute dwell and again, it pressure washed right out!

I used Publix brand "Drain Cleaner Gel" which uses sodium hypochlorite as it's active ingredient.
Sodium hypochlorite - Wikipedia, the free encyclopedia

Sorry for being long winded...I hope this helps out some of you that face the same problem I did. You can send checks to...lol









Thoroughly locked in screen...useless!








After 40 minute dwell...usable!


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## CenCoastDesigns (Feb 11, 2009)

Awesome. Good to know.


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## weille (Nov 19, 2009)

This works, tried on 4 screens years old


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## ocean502 (Jul 22, 2008)

Wow, that's awesome..I am new, and didn't realize you couldn't let those sit..Thanks again!


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## macumazahn (Jan 11, 2007)

Gonna try this out. You may have just got yourself on the Christmas list. At least a card or something. LOL.


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## prideofgumbo (Dec 23, 2007)

Nice. Gonna have to give this a whirl as well.


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## cv.graphink (Nov 25, 2010)

thank you very much for the info. somewhere in big shops, small shops, the garage, or even in the frontroom we all have screens that have emulsion locked up.


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## PrintsCharming (Jan 21, 2009)

Did it harm the mesh at all? It's kinda sketchy because you don't know how it's going to react with other chemicals. Good tip though.


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## wwpro (Apr 9, 2009)

PrintsCharming said:


> Did it harm the mesh at all? It's kinda sketchy because you don't know how it's going to react with other chemicals. Good tip though.


If the emulsion is locked your mesh is gone, so you have very little to loose here.


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## PrintsCharming (Jan 21, 2009)

if it harms the mesh then it's not worth the trouble at all. You'd be losing time.


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## weille (Nov 19, 2009)

PrintsCharming said:


> if it harms the mesh then it's not worth the trouble at all. You'd be losing time.


PrintsCharming: first response i didnt comment, but now?? are you serious?? locked screen means your only option is to have the frame reMeshed.. so again i ask, what are you talking about harming the mesh?? its a lost screen?


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## mrvixx (Jan 13, 2009)

And you can unclog your drain at the same time!!!


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## PrintsCharming (Jan 21, 2009)

weille said:


> PrintsCharming: first response i didnt comment, but now?? are you serious?? locked screen means your only option is to have the frame reMeshed.. so again i ask, what are you talking about harming the mesh?? its a lost screen?


have you read this post?


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## weille (Nov 19, 2009)

im pretty sure im the 3rd post.. stating it worked on 4 screens.. locked for years and nothing would break it loose. a few minutes with Draino with sodium hypochlorite and almost perfect and brand new. 

printscharming please explain your definition of a locked screen? how do you suggest getting the emulsion out? you must have an answer that does not have the chance at harming mesh, even though draino does nothing but help


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## ocean502 (Jul 22, 2008)

It TOTALLY WORKED!! I bought Draino gel, couldn't find the active ingredients anywhere. But let it set for 40 minutes and all pressure washed right out..YOU ROCK!


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## PrintsCharming (Jan 21, 2009)

weille said:


> im pretty sure im the 3rd post.. stating it worked on 4 screens.. locked for years and nothing would break it loose. a few minutes with Draino with sodium hypochlorite and almost perfect and brand new.
> 
> printscharming please explain your definition of a locked screen? how do you suggest getting the emulsion out? you must have an answer that does not have the chance at harming mesh, even though draino does nothing but help


what are you talking about? I asked if this method harmed the mesh. that is all. Someone replied what have you got to loose. I replied, If the draino harms the mesh, you would be wasting your time trying to fix it. very simple. I am not trying to argue with anyone. I'm not saying it doesn't work. Just asking a question.


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## BroJames (Jul 8, 2008)

For those who have tried it, is there any noticeable damage to the mesh?


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## bigduke1022 (Nov 5, 2008)

Does the drain cleaner harm the mesh at all, print wise? Any info would be great!


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## bigduke1022 (Nov 5, 2008)

Ok. What is the trick? I have tried this a couple times in the past couple days. I found some drain cleaner with sodium hypochlorite and let it dwell for 40 minutes. I then sprayed it down and nothing happened. It looks the same as it did before I tried this.


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## selanac (Jan 8, 2007)

Big Duke, you sprayed it down with a pressure washer? Did you try the brands they mentioned? One guy mentioned Draino Gel. That's not the same as Liquid Draino.

At least in the drain anyways. I've never been able to get Liquid Draino to work in my sinks. When they came out with Draino Gel, I tried it and it worked great. Best thing they ever came out with. 

Now that I'm reading this thread, it's a two for one cleaner. 

For the guys and gals who've tried it, does it take out old ink stains too?


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## kc6789 (Mar 28, 2010)

So r we confirming that Draino works as emulsion/haze remover!?


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## BST. (Jan 8, 2008)

TurboSi said:


> I used Publix brand "Drain Cleaner Gel" which uses sodium hypochlorite as it's active ingredient.


Thanks for the tip, will def try this!

I have 4 xlarge screens locked in, cuz they were too big and the part that stuck out of the dip tank dried.

cant wait to try this!


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## kc6789 (Mar 28, 2010)

Holy crap, I think I might try it too. Just a bit scared tho... :O


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## BST. (Jan 8, 2008)

kc6789 said:


> Holy crap, I think I might try it too. Just a bit scared tho... :O


I will have gloves, goggles, and a mask on when I try this... j/s


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## kc6789 (Mar 28, 2010)

BST. said:


> I will have gloves, goggles, and a mask on when I try this... j/s


No, I'm scared for my screens.


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## BST. (Jan 8, 2008)

kc6789 said:


> No, I'm scared for my screens.


if there like mine, better worth a try than collecting dust. 

but using drain cleaner, I'll def be covering myself.


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## selanac (Jan 8, 2007)

I tried it with No Luck at all. Well, maybe 1% if that. I did not see any deteration to the screens. Like someone else said, your only choice is to cut the screen out, and re-screen the frame. 

I should have taken a before and after shot. 

Anyways, I put the draino gel on both sides, let it sit for 40 minutes, and tried to spray it off with no luck at all. It was fun trying though, lol.


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## bern (Feb 14, 2007)

Thanks Doug , 
I have 8 large screens that I bought second hand . Looks like they were partially reclaimed . Tried with Fotochem 2005 paste on one screen , a little bit of the emulsion came out , tried same process again days later and nothing seemed to change . After reading your post I bought Mr Muscle Draino Gel ( Australian made ) . Donned respirator and gloves scrubbed screen for 5 minutes , within 2 minutes the emulsion was breaking down with the scrub brush and it pressure washed out with little effort . So it is very effective at cleaning these screens . Very happy with it all . Thanks


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## BroJames (Jul 8, 2008)

Have you tried getting the emulsion off with just the pressure washer?


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## bern (Feb 14, 2007)

BroJames said:


> Have you tried getting the emulsion off with just the pressure washer?


Yes I tried it with the pressure washer after the Fotochem paste so it should have worked then , it removed very little . Mine is not the most powerful pressure washer though .


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## selanac (Jan 8, 2007)

When I used the Draino Gel I only applied with a soft sponger paint brush. A little scrubbing but not much. Maybe I'll try tomorrow with a scrub brush instead and scrub it. 

I don't have a real preassure washer. I have the one that's advertised As Seen on TV. It's just a tube with a connector. Sells for $19.99. Works great for every thing else.


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## printing40years (Dec 27, 2008)

It will also eat a hole in your skin or eyes if any is splashed on you when you rinse it off. If you put those screen in the sun the lye will eat a hole through the mesh in ten minutes. Nasty stuff you are playing with.


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## printing40years (Dec 27, 2008)

It will also eat a hole in your skin or eyes if any is splashed on you when you rinse it off. If you put those screen in the sun the lye will eat a hole through the mesh in ten minutes. Nasty stuff you are playing with. The sooner you clean up after yourself the better. Emulsion


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## printing40years (Dec 27, 2008)

It will also eat a hole in your skin or eyes if any is splashed on you when you rinse it off. If you put those screen in the sun the lye will eat a hole through the mesh in ten minutes. Nasty stuff you are playing with. The sooner you clean up after yourself the better. Emulsion comes off easily with bleach or emulsion remover as long as it has totally dried before you put ink on it. That will lock it in every time. Don't be too rushed to print. Do it right. Then clean up right away. I'm sure the Everglades need just a little more lye washed into the waterways.


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## Alan Buffington (Oct 27, 2010)

Great stuff. You can also use caustic haze remover to soften the 'skin' of emulsions that cannot be reclaimed in much the same way. Don't leave either on too long as it will start damaging the threads in the mesh and make them weak.


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## JBuchanan (Jan 26, 2010)

Holy Triple Post Batman!

Seriously Lye is no joke it is extremely caustic, if you're going to use it take precautions by wearing gloves and some sort of eye protection.


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## Alan Buffington (Oct 27, 2010)

yes, 5 minutes max before the mesh starts begging for mercy


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## selanac (Jan 8, 2007)

Maybe its time to start rescreening my own screens. Any of you Caustic posters Screen their own screens?


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## BroJames (Jul 8, 2008)

I think you'll need 120 bar.


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## Bill Hood (Apr 11, 2007)

_*Here is an article that was published at Solutions Journal Magazine on Screen Cleaning Chemical Knowledge...*_ 
Lets face it we all must clean or reclaim screens on a daily basis. I know most of you put it off as you see it as perhaps the most unglamorous job in the shop. It may surprise you to know that it doesn’t have to be that way. In fact many of the harsh chemicals we use in the reclaiming process are also used in the clean rooms of some of the largest computer chip manufacturers in the world. They are also used in the food processing industry and in other places where cleanliness is required.

Recently, I had a conversation with a screenmaker who was completely unaware of the chemicals used in the reclaiming process. He had been reclaiming screens without the benefit of any personal safety devices such as eye protection, skin coverings or even a respirator. At the end of the conversation, I knew that I had to write about the screen cleaning chemicals for my readers at Solutions Journal Magazine. Enjoy!

*Ink Degradents*

There are specific ink degradents on the market for each of the different types of inks used by screenprinters. However, I must make a comment here about the use of mineral spirits as a substitute for commercial ink degradents

For decades now, I have used and recommended normal hexane or nhexane (mineral spirits) for cleaning up plastisol and like inks. However, I changed my mind earlier this year when I started hearing about the health related problems associated with the use of normal hexane. Nhexane is widely used in all sort of industrial cleaning and it is probably safe except when handled by humans that are unprotected with nitrile gloves, respirators and other personal safety devices.

In August 2009 an employee of Wintex Corporation, a manufacturer of touchscreen components, died due to nhexane poisoning. The nhexane was being used as a less expensive replacement to isopropyl alcohol for cleaning the touchscreens. A report by the Center for Disease Control revealed that 62-employees of the plant required hospital treatment for nhexane poisoning.

In October 2010 more employees at another Wintex Corporation manufacturing facility, this time located in China came down with nhexane poisoning and several employees had been in the hospital for over six months.

I no longer recommend the use of normal hexane or mineral spirits and have banned it from the School of Screenprinting. It's back to soy-based for me now. While many of the soy-based products have to be closely monitored for other materials, they are at least a step in the right direction.

*Emulsion Remover*

Emulsion remover is Sodium metaperodate. It is nothing more than the sodium salt of periodic acid (NaIO4).

When applied to emulsions it will cause the emulsion to soften. After a required dwell time, in which the sodium metaperodate should not be allowed to dry on the emulsion, the emulsion can be removed with a pressure washer.

For those times when the emulsion has become "locked" into the mesh the sodium metaperodate may not be strong enough to remove the emulsion.

The emulsion may have become "locked" into the mesh because of the use of chemicals such as lacquer thinner, isopropyl alcohol (used as hardeners for the printing of waterbase and discharge inks), or other "hot" chemicals that caused the excessive hardening of the emulsion to take place.

Likewise, the emulsion may buildup on the mesh because of underexposure. Even a slight underexposure will cause the buildup of emulsion over time. The biggest problem with this buildup is that it reduces the size of the mesh opening and creates ink starvation in those areas. One can often and easily see the two areas, i.e. the old ghost image, in new prints. This ink starvation can also cause the press operator to increase the number of strokes to achieve the required ink deposit, easily doubling or tripling the production time required to print the job.

To removed locked in or stubborn emulsion most screenmakers use a commercial dehazer. These products will help to remove ghost images, stains, and fragments of ink that have become embedded in the knuckles of the mesh from previous jobs. The most popular commercial dehazers on the market are caustic-based sodium hydroxide (NaOH) also known as lye and caustic soda and the lesser used potassium hydroxide (KOH).

*Sodium Hydroxide*

Solid sodium hydroxide or solutions of sodium hydroxide will cause chemical burns, permanent injury or scarring if it contacts unprotected human or animal tissue. If it contacts the eye it will cause blindness. Protective equipment such as nitrile rubber gloves, safety clothing and full face mask should be used at all times when handling the material or its solutions.

Sodium hydroxide is highly exothermic and the resulting heat can cause severe burns and it can cause clothing and other flammables to ignite. Sodium hydroxide is not only corrosive to some metals like aluminum it can produce an extremely flammable hydrogen gas on contact with aluminum. Since most screenprinting frames are made of aluminum, you want to be very careful with any open flames or electrical appliances which may create a spark when using sodium hydroxide.

All that said, you may be surprised to know that sodium hydroxide is used to wash or cause chemical peeling of fruits, vegetables and many other food products, such as poultry scalding, soft drink processing and it is even used to thicken ice cream. Olives are soaked in sodium hydroxide to soften them. And most pretzels are glazed with a sodium hydroxide solution before baking to make them crisp!

We also use sodium hydroxide as a home drain cleaning agent, to straighten or relax human hair, and as a paint stripper.

*Potassium Hydroxide*

This colorless solid is an inorganic compound commonly referred to as caustic potash. The solid translucent pellets are hygroscopic and when mixed with water will give off significant heat. Potassium hydroxide is used interchangeably with sodium hydroxide but has a higher cost.

You will be most familiar with potassium hydroxide as the chemical that leaks from alkaline batteries, where it is used as the electrolyte.

The same health risks and safety issues discussed above in reference to sodium hydroxide pertain to potassium hydroxide, however you should be aware that postassium hydroxide is a much more powerful chemical and can cause severe burns.

Postassium hydroxide is used in chemical cremation of humans and animals as it does an excellent job of hastening the decomposition of soft tissues to leave behind only bones. It is also used to remove hair from animal hides in the tanning process of making leathers.

Its most common use is in the manufacturer of biodiesel and to produce soft soaps, which use less water to liquefy and thus clean better.

*Pressure Washer*

I mention the pressure washer at the end of this article on chemical knowledge for a reason. The use of a pressure washer will do a much better job of cleaning the screens. At a minimum you will need a pressure washer that can deliver at least 1200 pounds of pressure per square inch (PSI). Studies has shown that mesh can endure pressures up to 4000 PSI without sustaining damage. However, you cannot use high pressure on stretch and glue frames near the edges as this pressure can cause the mesh to delaminate from the metal.

Now, what do you think the use of a pressure washer and the knowledge of the dangers of chemicals used in the reclaiming process have in common? The pressure washer produces an atomization of the dangerous chemicals into the air that we breath. For this reason you want to assure that all personnel working in the immediate area are protected and have the right protective gear. Also be aware that the unless properly exhausted these chemicals can settle on surfaces of equipment and furniture and thus be transmitted to the skin or even into the eyes and mouth of unsuspecting workers.


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## Alan Buffington (Oct 27, 2010)

Thanks Bill, 

You taught an old dog a few tricks here. Good stuff.


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## Bill Hood (Apr 11, 2007)

Alan Buffington said:


> Thanks Bill,
> 
> You taught an old dog a few tricks here. Good stuff.


Thanks, Alan! I'll add that to my resume. Dog Trick Teacher!


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## BroJames (Jul 8, 2008)

Mineral spirits would include lacquer thinners? I've heard of thinners being used to "degrease" screens.

Bill, 1200psi is 83 bar and that's nice to hear that it can bve used for reclaiming screens. Also nice to know that a good mesh can withstand 4000psi. 

But to clarify, I had always thought that 1200psi (83bar) at a respectable distance is for washing out fine halftones, 1500psi (104 bar) is the minimum for reclaiming screens and 1800psi (124bar) the more ideal to remove stubborn emulsion. 

BTW, most washers sold at hardware chains here are compact type and rated 100 bar (1450psi) to 120bar(1740psi). 








Will these do? Or are they meant for weekly household use?


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## Alan Buffington (Oct 27, 2010)

The small pressure washers sold at home improvement stores are great for developing screens, especially those using SBQ pure photopolymer emulsions. For reclaiming get the strongest and most durable you can afford.


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## BroJames (Jul 8, 2008)

The strongest I've seen at home improvement stores here are rated 120bar(1740psi). The most durable would be Karcher.

Correction: The most durable should be a smaller version of this one available at some home improvement centers.








The one I saw is about 50% larger than a compact washer laid horizontally. Don't know the power but think I'll ask the next time I drop by. But not exactly a design someone home-based prefers though.


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## MattD73 (Feb 28, 2011)

Tried in the UK with a well known brand of drain cleaning foam containing Sodium Hypochlorite.
Left screens for about half an hour, used a high powered jet to clean, and came up a treat!

The only advice I would give is to do it outside! 
Major fumage!


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## BroJames (Jul 8, 2008)

I think 10 minutes will get the job done


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## tpitman (Jul 30, 2007)

Screens cleaned and reclaimed with proper chemistry made for the industry and used with gloves and a respirator in the washout room will avoid the necessity of caustic products that may work but have no business in the shop. If you've got issues with emulsion lockup on a routine basis, you're doing something wrong. Exposing yourself to caustic chemicals to save some saggy wood-framed screens someone else neglected isn't worth the risk. I started printing in 2002 and I haven't had locked-in emulsion. Stay away from hot solvents like mineral spirits for cleanup. Buy proper press washes, ink degradents, emulsion removers, and degreasers. They work far better and cost no more in the long haul, and might save you from some health issues a ways up the road.


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## mimic (Nov 28, 2011)

tpitman said:


> Screens cleaned and reclaimed with proper chemistry made for the industry and used with gloves and a respirator in the washout room will avoid the necessity of caustic products that may work but have no business in the shop. If you've got issues with emulsion lockup on a routine basis, you're doing something wrong. Exposing yourself to caustic chemicals to save some saggy wood-framed screens someone else neglected isn't worth the risk. I started printing in 2002 and I haven't had locked-in emulsion. Stay away from hot solvents like mineral spirits for cleanup. Buy proper press washes, ink degradents, emulsion removers, and degreasers. They work far better and cost no more in the long haul, and might save you from some health issues a ways up the road.



When I first started I read that mineral spirits were used for clean up. And I underexposed some screens. So I have about 4-5 screens that I havnt been able to use or clean that are just sitting there.

Now, I always use proper procedure than rarely have any issues. But I still dont want to throw away $100 worth of screens.


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## gerryppg (Jan 29, 2010)

Think of it this way if you have a $15 screen locked up with emulsion why would you spend 30 minutes getting it clean? Not worth the time in my eyes.


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## ScreenFoo (Aug 9, 2011)

Because you only make ten bucks an hour?


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## gerryppg (Jan 29, 2010)

ScreenFoo said:


> Because you only make ten bucks an hour?


 Lol well I guess it depends on whether you are working for someone else or not.


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## Alan Buffington (Oct 27, 2010)

Here is some info on WHY emulsion gets locked into mesh: If you under expose SBQ pure photopolymer emulsions they are still sensitive to light, as well as harsh cleaning chemistry. So with an under exposed screen when you wash up plastisol with mineral spirits, acetone, MEK, or any solvent cleaner like screen openers you are chemically cross linking the un exposed emulsion. To prevent this either get a 5kw exposure unit, or post expose in the sun to complete the cross linking. SBQ emulsions need to completely expose or you can have lock in occur. Age is also an issue. Any emulsion stored for long periods like a year or more get very dry and are difficult to reclaim. Dip tanks are an answer using a little bit of haze remover and a concentrated emulsion remover chemistry. In worse case scenarios you can use caustic haze remover, but it is cheaper if labor takes 30 minutes per screen to reclaim to just re-mesh it. Another lock in issue is with emulsion remover. If you allow emulsion remover to dry on the screen it will be very difficult if not impossible to reclaim. So post expose your developed screens, and stick with commercial reclaiming solutions. DIYers can experiment with some of the caustic solutions but avoid this if you have employees, unless you want to hand them the keys to your shop someday in court. 

Alan Buffington
Murakami Screen USA
800-562-3534


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## BroJames (Jul 8, 2008)

gerryppg said:


> Think of it this way if you have a $15 screen locked up with emulsion why would you spend 30 minutes getting it clean? Not worth the time in my eyes.


Because the most part of the 30 minutes can be spent doing something else instead of idle waiting?


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## beanie357 (Mar 27, 2011)

gerryppg said:


> Think of it this way if you have a $15 screen locked up with emulsion why would you spend 30 minutes getting it clean? Not worth the time in my eyes.


Because thats 30 an hour and you pay staff only 15? Because it's not a crap wood, but a new shur-loc 305 panel? Because it's a challenge? Because it's only a hobby? Because you own stock in Liquid Plumr? Because you like the smell? Because the smell keeps people you don't like away?

Ah, the wonders of human reasoning. It's all over the place. The Murakami chap has the bottom line sensible post.

Merry Xmas and happy holidays!!


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## gerryppg (Jan 29, 2010)

If you dont have anything more productive (money making) to do in 30 minutes than to clean a CHEAP $15 screen than you should not be in business period. A screen recliam should take you 5 minutes tops. If you dont have enough screens on hand to set aside or throw out a screen that will take you 30 minutes of money making time than you should buy more screens. Merry Christmas.


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## BroJames (Jul 8, 2008)

The issue is not 3 or 30 minutes of soaking the screen but on time management. In 30 minutes, one can print a few dozen of shirts, prepare artworks, talk with customers, or spend some idle time "smelling the flowers".


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## gerryppg (Jan 29, 2010)

I guess the better way to approach it is to find out why you are getting locked in emulsion and how to avoid it. In the past 2 years I have had one pop up on me and I figured it to be underexposure and the screen opener. That screen sits on my rack as a reminder.


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## BroJames (Jul 8, 2008)

prevention is indeed better than a cure


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