# Need help mixing emulsion and Diazo



## sickfingers (Nov 21, 2009)

Hello,

I am new to the screen printing world. I purchased some Xenon 903Wr emulsion (1qt) and it came with some Diazo. 

The instructions say to fill the diazo bottle with warm water and shake well until powder is dissolved. Mix dissolved diazo into the emulsion and mix thoroughly. allow to stand for 1 hour. (from the research on here I read I should use cold water not warm - also it sits for an hour to get rid of the bubbles)

My main question is Do I need to put the whole bottle of diazo into the emulsion? I'm only printing 1 screen ( a sample) just to get familar with it. Can I take some emulsion out and mix it with some disolved Diazo, Or do I just ned to mix the entire thing and simple store it for later?

My next question is - If I am to mix the entire thing and store the rest for later, What do I mix it with (A Paint stick? Shake it?)

Thanks for all your help - it is greatly welcomed.

Dave


----------



## printing40years (Dec 27, 2008)

Yes. Add it all. Use cool tap water. It is premeasured for your quart container. Shake it or stir it well. Keep it in a dark cool place or in the refridgerator. It should last six months or so. Good luck


----------



## sickfingers (Nov 21, 2009)

Thanks so much, My wife and I are a bit excited to get started tonight with this - we just didnt want to waste the etire container being impatient and screwing something up. 

Thanks again



seriwiz said:


> Yes. Add it all. Use cool tap water. It is premeasured for your quart container. Shake it or stir it well. Keep it in a dark cool place or in the refridgerator. It should last six months or so. Good luck


----------



## sickfingers (Nov 21, 2009)

Ok, I mixed everything well. Added the disolved solutions in a dark room and stir very well. It appeared either I got tired and weak or the emulsion thickend. Hopefully this is suppose to happen. Now I placed the lid back on and we wait for an hour or two.

Thanks

Dave


----------



## snackdaddy185 (May 17, 2008)

I always thought you needed to use distilled water. Would tap water make any difference?


----------



## printing40years (Dec 27, 2008)

Don't wait. Go for it. A few bubbles won't ruin the screen. Coat it slowly and evenly on both sides and let it dry completely horizontally in front of a fan. Better to over expose it than to underexpose it. Dry completely. Tape around the edges and print. Good Luck


----------



## Rexx (Aug 13, 2009)

snackdaddy185 said:


> I always thought you needed to use distilled water. Would tap water make any difference?


i have used tap water and never had a problem.


----------



## InkedApparel (Mar 18, 2009)

seriwiz said:


> Don't wait. Go for it. A few bubbles won't ruin the screen. Coat it slowly and evenly on both sides and let it dry completely horizontally in front of a fan. Better to over expose it than to underexpose it. Dry completely. Tape around the edges and print. Good Luck


no a few bubbles wont ruin the screen ...unless the few bubble are right in the middle of your artwork......leave the cap of the emulsion off a little to let the air bubble air escape...I have rushed and not waited long enough to use the emulsion after I mixed the diazo and ruined a few screens..my advice is to give the emulsion a few hours to let the air bubbles escape......I use room temp bottled water ...never had an issue.

Inked


----------



## RichardGreaves (Nov 7, 2006)

Diazo bonds with water eventually. Water acts as a barrier to UV reaction. Most of the bubbles you see when you mix the diazo with water, is a reaction of the diazo and it does give off a small amount Nitrogen gas. That's why you should allow freshly mixed diazo to "degass".

It is the water that degrades/ages diazo. Cold does very little to prevent water from bonding with diazo, but it is true that cold will slow down any reaction. Handy people can still get decent stencils after 45 days, but solvent or water resistance from diazo will degrade with time. You will need to re-calibrate exposure for older emulsion. It's that instability that makes manufacturers caution you to use within 45 days for the best results. All the unexposed sensitizer you don't react, will hinder stencil removal.

There are many instructions warning not to let your emulsion get too hot. In the summer, many people put diazo sensitized emulsion in the refrigerator because it's the only place you can think of that's cooler than your coating room. At 42°F you are 10°F degrees from ice cream. If you coat with 42°F emulsion, when it warms, as it dries - it will drip.

Diazo sensitized emulsions start to age when you mix the sensitizer with water and the time clock starts ticking.

Even if you are printing small runs with water-based ink, there are several pre-sensitized non-diazo, SBQ emulsions sold in quarts with an 18 month shelf life perfect for newbie print runs.

If you are printing with plastisol (harmless to any stencil), change to an SBQ and ask why your distributor told you to buy a diazo emulsion that begins to degrade after 45 days.


----------



## T Shirt Designs (Jul 21, 2009)

REFRIDGERATOR?? Really I never heard of this. Is this for all emulsion? I have ulano QTX.


----------



## RichardGreaves (Nov 7, 2006)

Most emulsions are labeled with warnings to store below 85°F like all photographic products. 

The flaps on the box your QTX came in should say:


----------



## Deyan (Mar 19, 2010)

sickfingers said:


> Hello,
> 
> I am new to the screen printing world. I purchased some Xenon 903Wr emulsion (1qt) and it came with some Diazo.
> 
> ...


Can you send me the this instructions?


----------



## jkewl99 (Feb 9, 2012)

Good Morning,

I am also new to the Screen Printing World, I Purchased a quart of Hybrid Emulsion for simple SPOT Screen Prints. THe instructions of the Diazzo it said fill the bottle half way and shake thoroughly. Well the darn bottle is black and I filled almost 3/4, will there be a problem with 1/4 more oz of water in the emulsion?


----------



## RichardGreaves (Nov 7, 2006)

*Harm adding a extra water to diazo sensitizer?*



jkewl99 said:


> I Purchased a quart of Hybrid Emulsion for simple SPOT Screen Prints.
> 
> THe instructions of the Diazzo it said fill the bottle half way and shake thoroughly.
> 
> ...


No. Most dual cure emulsions are about 60% water. The worst that will happen is the emulsion MIGHT flow a little easier. I would ignore it.

Next time, don't be afraid. Use minimum light for the short amount of time you need to aid your adding water. 10 seconds isn't going to do any harm.

As I type this, it comes to mind that the shaking in the tiny diazo sensitizer jar might be a bigger problem so read the T-Shirt Forums link below.

*Homework*
Mixing diazo with water Nov. 6, 2007 
http://www.t-shirtforums.com/screen-printing/t32101.html#post186705

*Last*
I assume you're using Ryonet's new WBP *Hybrid Emulsion* (CCWBP), rather than Ulano's QX-1 *hybrid* Pre-Sensitized Dual-Cure Emulsion because you're adding diazo.

If you are printing details & halftones, a dual-cure will deliver the best resolution. Diazo sensitizer slows sensitivity of dual-cure emulsions, but adds water or solvent resistance. 

If you are printing water-based ink, you need diazo for stencil resistance, but if you're printing plastisol ink that doesn't harm any stencil, you can get faster exposure with an SBQ pre-sensitized emulsion with an 18 month shelf-life, in bulk like Ryonet's HiFi Photopolymer Emulsion for less money.


----------



## tpitman (Jul 30, 2007)

If you've got a sensitive-enough scale, you can split containers of emulsion and the diazo syrup in two.
I use mostly Ulano's QX-1, but bought some 925WR for waterbased printing. A tech at Ulano told me (as Mr. Greaves points out) that the degradation of the emulsion doesn't start until the diazo is added, and just to be careful in dividing the components to assure proper proportions when mixing the subsequent smaller batches. I've done this and it works out very well, stretching out the service life of a batch of dual-cure emulsion. A scale that'll read 10ths of a gram is advisable for accuracy.

As an aside, one thing I found I like about the 925WR is films don't tend to stick to it after exposure as much as the QX-1, and I'm guessing it's due to more resistance to any moisture absorbed from the air in the case of the 925WR. Even in a dehumidified darkroom where my drybox is located, my films often transfer some ink to the underside of QX-1 coated screens.
I'm thinking I may switch entirely to the 925WR.


----------



## ScreenFoo (Aug 9, 2011)

Great reference, and idea--I always wondered why powdered diazo was so lumpy, but was never smart enough to mill it myself. (Home brew experience should have kicked in there. )

I'd also toss it out there that lukewarm distilled water is far easier to use than room temp or cold. A coffee cup and microwave are probably already at your shop.

Interesting aside, Tom--I had the same problem with QX-1 as well as the DP390 that preceded it with laser positives. I need to try out that 925-WR though.

Although we still have less than ideal conditions on the exposure unit, it seemed to be somewhat temperature and vacuum coupled in my experience--but in a semi-arid region at 15% average RH, I'm pretty sure it wasn't the humidity.


----------



## RichardGreaves (Nov 7, 2006)

*Weighing Diazo to use it in your own separate mixture*

It's common for screen makers to dry stencils, but forget about all the 80% water in inkjet ink or moisture in vellum finish laser paper. Dry stencils, not designed to resist the charms of water, soak it right up - especially under lamps that generate water evaporating heat.

Powdered diazo can clump even in a sealed container from the factory. Yes, use warm water (no hotter than skin temperature - make the baby bottle test), or it will kill the diazo's ability to react with UV energy.

*Beware* - before you buy Ulano 925WR (995WR in Europe), it's supplied with *syrup *diazo sensitizer as a function of it's industrial, more durable water resistance. 

I will look up my other posts about diazo dividing: Wear a mask (poison), in a clean, UV light safe area.

Posts 5 & 7 2009
http://www.t-shirtforums.com/screen-printing/t77006.html#post462767


*Textile Printers:*
Yes, think of 925WR *only if* you've had a long run *failure *with the much faster exposing QT-Discharge.

925WR takes more effort to reclaim and expose - which is worth it to avoid printing delays on press.

My direct emulsion recommendation for combination plastisol/water-base ink shops is QT-Discharge, which is supplied with *powdered *diazo. When I started at Ulano in 2005, my very first direct emulsion project was a *modern *water-resistant product for the re-surging discharge market. The great Ulano chemists knew more about reclaiming & photo-polymer sensitizers than they did when 925WR was invented. 

Don't be distracted by Discharge in the name - focus on the QT in the name.

Try an experiment and make an exposure test of QT-Discharge *without *adding diazo for your harmless to stencils plastisol ink.................


----------



## tpitman (Jul 30, 2007)

Tubelite didn't have the QT-Discharge in stock (at least at the time I bought the 925WR). Curiously, why do you not recommend splitting the diazo syrup by weight? I measured out the contents onto a .1 gram scale and mixed up half with the appropriate amount of water with half the quart of the emulsion. So far so good. Slower exposures as was expected, but no stencil breakdown with waterbased ink and so far reclaims have gone well. Am I in for a surprise I haven't anticipated?
Thanks for all of your comments, by the way. Much appreciated.

Also, is the addition of diazo to the QT-Discharge strictly to add water resistance? Are you suggesting that the emulsion with no addition will function normally when limited to plastisol printing?
Thanks.


----------



## RichardGreaves (Nov 7, 2006)

tpitman said:


> Curiously, why do you not recommend splitting the diazo syrup by weight?
> 
> I measured out the contents onto a .1 gram scale and mixed up half with the appropriate amount of water with half the quart of the emulsion.
> 
> So far so good. Slower exposures as was expected, but no stencil breakdown with waterbased ink and so far reclaims have gone well.


I worried about syrup lost in the process, the sticky mess on tools & scale protection, putting the sticky syrup back into the bottle for the second dose - but you've proven me wrong. 

I certainly shouldn't have written 'nobody' in the other post. 

I understand that your regular distributor didn't have QT-Discharge, but I urge you to consider the specific benefits I listed which may apply to other stencil manufacturers. I usually answer broader than the actual posted question to inform readers - _generally._



tpitman said:


> Also, is the addition of diazo to the QT-Discharge strictly to add water resistance?


Added to an emulsion base, diazo sensitizer can increase water or solvent resistance & increase resolution. You'll see many stencil manufacturers offer diazo as an additive to increase resistance in photo-polymer sensitizer products. 



tpitman said:


> Are you suggesting that the emulsion with no addition will function normally when limited to plastisol printing?


...You might well think that. I couldn't possibly comment. 



=====
I just noticed 'Similar Threads' in the page footer. There are checks in mine. I think that means I have posts in them. I'm going to check.


----------



## tpitman (Jul 30, 2007)

Again, thanks for your comments and the benefits of your experience. It's nice to have folks on here from the supply side to offer up a little "inside baseball" to those of us using those supplies.


----------



## thronedesigns (Oct 17, 2014)

I thinking of getting the Ryonet dual cure emulson (blue) my question is I'm getting the gallon with the mix would I mix the whole gallon with it or use quarts at a time ? I know they said once mixed its shelf life is 3 months or so


----------



## haischool (Jan 17, 2014)

i thought that you could buy emulsion that's ready to go out of the container? without having to mix, etc.


----------



## sben763 (May 17, 2009)

You can get presensitized emulsion but its not diazo and the latitude for exposure is narrower then diazo. Presensitized has a 1-2 year shelf life though if you keep it under 75F. The CCI stuff Ryonet sell though is bad if you don't have proper humidity control Satti Chem PHU blows the HI-FI they sell away and is cheaper, can also do waterbase and discharge with post exposure.


----------



## mfegypt (Jun 1, 2011)

*Re: Harm adding a extra water to diazo sensitizer?*

Hi,

I had a problem and was wondering if you could help me out with it. I have a stock of about 40 litres of diazo sensitizers from Fujifilm-Sericol UK. They used to work perfectly but all of a sudden all the sensitizers became too thick ( almost clogged) to the point that when I add water to them, it just sit on top of it. My question is: do you recommend or suggest any method for me to try and revive this sensitizer back to be able to use. 

Your answer would be very highly appreciated as it would save me a lot of money.

Best regards,

Mohamed Fatih 






RichardGreaves said:


> No. Most dual cure emulsions are about 60% water. The worst that will happen is the emulsion MIGHT flow a little easier. I would ignore it.
> 
> Next time, don't be afraid. Use minimum light for the short amount of time you need to aid your adding water. 10 seconds isn't going to do any harm.
> 
> ...


----------



## splathead (Dec 4, 2005)

*Re: Harm adding a extra water to diazo sensitizer?*



mfegypt said:


> Hi,
> 
> I had a problem and was wondering if you could help me out with it. I have a stock of about 40 litres of diazo sensitizers from Fujifilm-Sericol UK. They used to work perfectly but all of a sudden all the sensitizers became too thick ( almost clogged) to the point that when I add water to them, it just sit on top of it. My question is: do you recommend or suggest any method for me to try and revive this sensitizer back to be able to use.


How old is your stock? There is a shelf life of only a few months.


----------



## mfegypt (Jun 1, 2011)

*Re: Harm adding a extra water to diazo sensitizer?*



splathead said:


> How old is your stock? There is a shelf life of only a few months.


I had the stock for about 6 months now, and add to the add almost 3 months from production, so I am looking at 9 months from production date. The thing is I have beeen using their product for more than 10 years now with no problem and I have always been told that the shelf life of the emulsion / diazo sensitizer is 2 years ( not mixed of course ). I never had a problem with my stock that usually lasts for almost 18 months, but when I called the company this time they told me it might be a heat wave in Egypt, where I work from !! I didn't buy that of course, and I am just looking for any ways to try to make used of the stock I have at the moment.


----------

