What kills a dip tank

[Binkspot]

We have been using our dip tank for a little over two years now.

The first batch Easiway lasted about four months. Figured we were topping it off with straight water and just diluted it.

Second batch, Easiway lasted a little over 8 months. I would top off the tank with a mixture of the emulsion remover and water, same ratio as originally filled. We moved to our new location and the solution died. Wrote it off to moving the tank. I had pumped the solution through a copper wand I had used for pumping oil out of drums with a brass gear pump. Thinking there was something in the wand or pump that killed it.

Third batch CCI Micro wash II lasted almost a year. I would make up the loss with a strong mixture, double what was recomended. We ran a average of 15-20 screens a day through it. Really can not complain. 

The most recent batch lasted six weeks then dead. Topped it off the same way, ran the same amount of screens through, maybe a little less being our summer slump.

My concern is dropping more money into this tank and having it fail quickly again. We have not changed our process or anything pre dip but have been using a bunch of diffirent emulsions lately. That being said what factores into the death of the solution more on a chemistry level. Does the aluminum in the frames react to the solution from soaking too long? Am I introducing something else into the tank that may be killing it possiably an ink or emulsion or maybe the cleaner I am using on press, etc. I hate to not use it because its a time saver for us.

[sweetts]

Is the new place on well water maybe something there.
 If not maybe its the summer blend from the water department higher chlorine and algicide level. It would stand to reason that the water and what's in it is the variable is all else is the same. I would contact the company and see how old the stuff was when you got it and see if they could test the solution or give you some insight I would bet its something in the water.




RT Screen Designs
www.rtscreendesigns.com

[chubsetc]

My only experience with the solution dying happened when when I was trying to reclaim a couple very stubborn screens.  When it wouldn't come off I decided to leave it in overnight.  Boom, next day perfectly working solution was rendered inert.  I definitely think leaving your frames in too long is one of the reasons the solution may die.

[GKitson]

Brian,

Dip tank chemistry balance is just that, a balancing act.

Too strong and you eat mesh tape and wa$te money and too weak you will wa$te time.

I have heard that IRON will kill emulsion removal reactivity and my favorite story is of digging the partial remains of a hammer out of a large dip tank that did 900+ screen per day.  It was charged with a brand new drum of ER chemical and a couple hundred gallons of water and only lasted a week instead of 3 months.  Expensive lesson.

In our shop was refresh with 2 oz. of ER concentrate every batch for best workflow throughput.  An average batch is 60-75 screens and we dump/replace the entire tank twice a year when replenishment no longer speeds things up.  That is typically about 7000 screens on less than 2 gal of ER chemical.

Emulsion remover never stop working until it is dead and if you leave mesh with emulsion in too long or allow the emulsion to completely be removed from the mesh you will have a continuous reaction going on in the bottom of the tank on the sludge reside. 

What this means is you should soften emulsion in the dip tank and remove the screen with most if not all of the emulsion is still in the mesh and finish removal with your power washer, again the balance thing.

 I have forward the question along to a couple of screen chem geeks for more info, I'll post what additional I learn,

~Kitson

[Binkspot]

Thanks all.

The water is a good point but we are on city water, both shops on the same service from the same supplier. But still may be a factor like you said the chlorine content, seasonal change or something else.

We do not let the screens soak long enough to for the emulsion to fall out of the screens. Last time we did a change I was surprised how little gunk was at the bottom of the tank, maybe 1" at the most almost all ink and tape scraps.

You maybe onto something with the iron. I have a couple of old Newman's (please don't laugh they have the old narrow plastic end caps) that I added into the inventory back in May. I noticed the bolts have flash rust on them like a cheap grade of stainless like 18-8. Maybe I'll pull those out of roatation and replace the bolts with 316 ones.

[Homer]

We had trouble with ours too, we were constantly chasing the mixture. We went through 5-6 different chemical combinations. My last attempt was micro wash II and the first few refills were about 3-4 months apart. We would notice the tank dieing a bit and add another 5 gal. we did this for over a year. Then our last go-round lasted 20 working days. nothing in the bottom of the tank, no metal, no sludge, nothing. could not figure it out. I thought underexposure but we tested with stencil remover and it was melting like it should, step test was spot on. So no more tank, it was a bear to mess with. If I feel like screwing with it again, I am going to put straight stencil remover in it -no more ink/emulsion combos.

[Frog]

We had trouble with ours too, we were constantly chasing the mixture. We went through 5-6 different chemical combinations. My last attempt was micro wash II and the first few refills were about 3-4 months apart. We would notice the tank dieing a bit and add another 5 gal. we did this for over a year. Then our last go-round lasted 20 working days. nothing in the bottom of the tank, no metal, no sludge, nothing. could not figure it out. I thought underexposure but we tested with stencil remover and it was melting like it should, step test was spot on. So no more tank, it was a bear to mess with. If I feel like screwing with it again, I am going to put straight stencil remover in it -no more ink/emulsion combos.

I have heard many say that they had poor life with the combo mix.

I could see a three tank set up being the hot set-up.
1. Ink cleanining
2. Emulsion remover
3. Water for the first stage of development and rinse-out

[Printficient]

We had trouble with ours too, we were constantly chasing the mixture. We went through 5-6 different chemical combinations. My last attempt was micro wash II and the first few refills were about 3-4 months apart. We would notice the tank dieing a bit and add another 5 gal. we did this for over a year. Then our last go-round lasted 20 working days. nothing in the bottom of the tank, no metal, no sludge, nothing. could not figure it out. I thought underexposure but we tested with stencil remover and it was melting like it should, step test was spot on. So no more tank, it was a bear to mess with. If I feel like screwing with it again, I am going to put straight stencil remover in it -no more ink/emulsion combos.

I have heard many say that they had poor life with the combo mix.

I could see a three tank set up being the hot set-up.
1. Ink cleanining
2. Emulsion remover
3. Water for the first stage of development and rinse-out

There is a rumor that an industry guru and an industry idiot are working on a totally enclosed pre-press solution as we speak.  Prototype expected in the next couple of months.  Open tank, place screen, close tank, push button, done.  Repeat.

[Binkspot]

So what you are saying Sonny is I should stop dragging my feet on that project in my"lab" and finish it. 

[Printficient]

So what you are saying Sonny is I should stop dragging my feet on that project in my"lab" and finish it. 

Uh Sure???

[beanie357]

With our water coming through outdated pipes, high chlorine and iron are sporadic. Enviro was 2 seems to have varying life.
Bet it is water issues, as this makes lots of sense.

[Gabe]

We had trouble with ours too, we were constantly chasing the mixture. We went through 5-6 different chemical combinations. My last attempt was micro wash II and the first few refills were about 3-4 months apart. We would notice the tank dieing a bit and add another 5 gal. we did this for over a year. Then our last go-round lasted 20 working days. nothing in the bottom of the tank, no metal, no sludge, nothing. could not figure it out. I thought underexposure but we tested with stencil remover and it was melting like it should, step test was spot on. So no more tank, it was a bear to mess with. If I feel like screwing with it again, I am going to put straight stencil remover in it -no more ink/emulsion combos.

I have heard many say that they had poor life with the combo mix.

I could see a three tank set up being the hot set-up.
1. Ink cleanining
2. Emulsion remover
3. Water for the first stage of development and rinse-out

There is a rumor that an industry guru and an industry idiot are working on a totally enclosed pre-press solution as we speak.  Prototype expected in the next couple of months.  Open tank, place screen, close tank, push button, done.  Repeat.

YO @ SONNY what are they going to name the product, any idea

[Printficient]

We had trouble with ours too, we were constantly chasing the mixture. We went through 5-6 different chemical combinations. My last attempt was micro wash II and the first few refills were about 3-4 months apart. We would notice the tank dieing a bit and add another 5 gal. we did this for over a year. Then our last go-round lasted 20 working days. nothing in the bottom of the tank, no metal, no sludge, nothing. could not figure it out. I thought underexposure but we tested with stencil remover and it was melting like it should, step test was spot on. So no more tank, it was a bear to mess with. If I feel like screwing with it again, I am going to put straight stencil remover in it -no more ink/emulsion combos.

I have heard many say that they had poor life with the combo mix.

I could see a three tank set up being the hot set-up.
1. Ink cleanining
2. Emulsion remover
3. Water for the first stage of development and rinse-out

There is a rumor that an industry guru and an industry idiot are working on a totally enclosed pre-press solution as we speak.  Prototype expected in the next couple of months.  Open tank, place screen, close tank, push button, done.  Repeat.

YO @ SONNY what are they going to name the product, any idea

Yep