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screen printing => Equipment => Topic started by: mimosatexas on January 23, 2014, 03:30:33 PM
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I finally bit the bullet and bought a 5 gallon of easiway supra to start using my diptank since I already use the easiway 701 and love it. This morning I was looking at the bottom of the tank, and what I originally assumed was just staining is actually a thin, uniform layer of cemented on emulsion sludge. I have read plenty of warnings about sludge and leaving screens in too long killing the tank chemistry, so ideally I would like to remove this prior to filling it. I tried spraying on some emulsion remover and a bit of water and let it sit for the last few hours, and not a dent.
Anyone have a suggestion on how to remove this, or if it needs to be removed to prevent chemistry issues? Thanks!
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sometimes you can roll it up like a carpet, or you can use a dehaze/deagreaser to kill it...you might have to scrub it
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It's definitely not going to roll up. It is basically cemented to the bottom of the tank. I'll toss some tougher stuff than the emulsion remover in and see how it does...
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Ours used to build up at the bottom, sometimes 5-6" thick and we would drain the tank and use a shovel to peel it out of the tank. I never noticed that it does any harm to the chemistry and as long as we recharged it every 500 or so screens, it worked just fine no matter how thick the sludge was in the bottom. Once out of the dip tank it dries up and there is one lying somewhere around the shop that I haven't done anything with other than move it to different places in the shop to see if others will do anything with it. Some of the things I do around here to entertain myself.
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I think the problem is this is already dry, so you can literally crack off small pieces of it, but it is reeaaallly stuck onto the bottom. If the current soaking doesnt do anything to it, I am just going to leave it in there. I would obviously prefer a pristine tank to start with, but what can you do...
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Try some dish washing soap and some hot water that should soften it up so you might can peel it out.
Darryl
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Success! I finally just put the whole think into my washout booth sideways and blasted the hell out of it with the pressure washer. That got a lot of it started. Then I grabbed a rubber mallet and wacked at it from the back and after about 30 minutes of switching between those two methods it's as good as new!
I build a 14 inch tall base on casters for it and finished filling it up a minute ago. Glides around effortlessly despite weighing about 350 pounds, and tall enough to drain into a bucket if necessary.
edit: any suggestions on keeping it a constant temp? Would one of those glass enclosed fish tank heaters work?
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Success! I finally just put the whole think into my washout booth sideways and blasted the hell out of it with the pressure washer. That got a lot of it started. Then I grabbed a rubber mallet and whacked at it from the back and after about 30 minutes of switching between those two methods it's as good as new!
Except for the 12" crack! LOL!
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I know when developing the stencil that the water temp should be at 125°F to help with removing the unexposed emulsion.. so a diptank, filled with water, and set at the recommended temp is a smart move.. To help at the reclaming stage, a constant flow of hot water about 150°F is ideal, so your water should (before being fed to your pressure washer) be plumbed through some form of heater that could supply the volume needed for the number of screens you do at once.. Heating an underexposed screen on press whether by flashing or even during the print stroke (in the case of autos) will continue the arcing of the emulsion that didn't crosslink properly and cause problems with reclaiming..
I wonder what reaction reclaim chemicals has to a constant hot temp? What does the kinetic energy do it's ingredients? suspend them or colide them? maybe mutate them into something undesired? I don't know..
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Success! I finally just put the whole think into my washout booth sideways and blasted the hell out of it with the pressure washer. That got a lot of it started. Then I grabbed a rubber mallet and whacked at it from the back and after about 30 minutes of switching between those two methods it's as good as new!
Except for the 12" crack! LOL!
This crack's for you...........
http://www.oddee.com/item_98258.aspx (http://www.oddee.com/item_98258.aspx)
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Success! I finally just put the whole think into my washout booth sideways and blasted the hell out of it with the pressure washer. That got a lot of it started. Then I grabbed a rubber mallet and whacked at it from the back and after about 30 minutes of switching between those two methods it's as good as new!
Except for the 12" crack! LOL!
i honestly was terrified it would crack, but it didnt even come close. i could probably take an axe to this thing...
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We use Supra and I just drain the tank every few months, scrape out the muck on the bottom, strain the fluid back in with a screen as a filter and keep on going.
The Supra and the 701 are a great combo.
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Mind going into more detail on your process Evo, like cleaning process, chemical order, dwell time in the tank, etc.
Glad to hear you're happy with the combo. I saw pretty mixed reviews, but it was one of the only two chemical brand combos that people seemed to like and is stocked by my local guy.
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testing now. water is really cold though. definitely want an easy way to keep it at a constant temp.
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Aquarium heater, Ebo Jager brand.
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Cool, I have one laying around too :)
In an effort to dump as much info into this thread as possible for anyone else using or thinking about using a dip tank, I am going to update with my first impressions and progress. To preface, I have a 47 gallon tank that holds 10 23x31 statics with room to spare. I used one 5 gallon of the Easiway Supra, though this equates to a somewhat lower concentration than they suggest.
First thought: WOAH!!! I just got done with my first 10 screens. I set a timer for 10 minutes thinking the lower concentration and cold temperature would require longer to work. I was wrong. I filled it with a combination of everything from 280 mesh to 110, some hardened, some not, some had been cleaned with 701 before, some had only had ink scraped out. ALL of them were basically dripping off the screen after 10 minutes. I was able to fully pressure wash out the stencils on all 10 in about 4 minutes. The ink degradent aspect of the Supra didn't do much though to be honest. On the screens I didn't hit with 701 first, they definitely needed a quick scrub after. I am going to degrease in a moment. So far, VERY good! Has already saved me a lot of scrubbing, especially on the 110's that were slow coated 2/2 for my whites :)
update: Just finished screen #30...
I am kicking myself for not having gotten the tank setup earlier. Doing 30 screens in less than 2 hours would have been seriously pushing it without the tank, and after this session I am not even tired/sore.
The only thing I need to figure out now is a stronger/better dehaze/degreaser. I am using the pink stuff (ICC 858), but I need something that will more effectively get rid of the ghosts from my poly white screens or where emulsion failures with discharge have happened. The Murakami 700 stuff works to fix those when the normal process doesn't, but if something could handle most of those kinds of stains with a quick scrub and rinse after the tank I would be thrilled. Any suggestions?
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Welcome to 2014!
Suggestion: ditch the Pink Stuff. It's garbage.
Here's my suggestions and my usual method(s):
1) You need about 2-3 more gallons of Supra to your mix. Add Supra, full strength only, little by little as you replenish the tank periodically till your mix is a bit stronger.
2) Remove all non-permanent tape and scrape ALL the ink out of the screens. Leave only a thin film, no goop. The Supra doesn't do much degrade the ink as "detach" it from the screen. The more you pull out before dipping, the better. (less muck to clean up in the washout sink) I use a Hyde 4" putty knife for final ink removal. All screens going to the tank get a last once over with the scraper (and the press ops do a sh!# job, so it's almost always required)
3) I fill the tank with screens, then after 5-10 minutes I pull one from the back/add one to the front as I go along. That way all the screens in the tank will have been soaking for awhile as I go. After a screen is dipped, keep it immersed and soaking until it can be washed out. If Supra dries on the emulsion, kiss the mesh goodbye. It will lock the emulsion permanently.
4) Pull a screen, blast out the emulsion and ink from both sides, then scrub the whole thing with 701 (the mesh AND the frame), and blast it again from both sides. Make sure to clean all ink and stains from the mesh and frame. Hit it right away after you scrub on the 701. If you leave it on, it may actually set some ink stains a little. If you apply once to heavy ink haze and blast it right away, and there is a light haze left, sometimes hitting it with 701 again and blasting one more time will clear it completely.
5) Flood rinse the screen carefully from both sides
6) Skip the degreaser unless it's brand new mesh. Yes, you read that right. You're welcome.
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BTW - get a second tank for clear water developing of burned screens. Pull a screen from the exposure unit, drop it in the tank while you set up the next exposure. Pull the screen out and lightly rinse while the emulsion seems to leap out of open areas of the stencil.
You will be kicking yourself sore over this one.
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Looking to purchase our first dip tank. This seemed like a good thread to bring back to life. Mimosatexas are you still happy with this setup, or would you recommend any changes? Thank you.
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I think there is one shop on the forum who did not like using the dip tank. Everyone else I have talked to LOVES theirs. I recently tried out a bunch of different methods as an alternative (stack method with differing quantities and chems) and the tank still wrecks them for efficiency and quality of the final reclaimed screen.
I basically follow exactly what Evo posted above. I use Supra in the tank (now using 6 gallons in my 47 gallon tank, rest water). I card off ink and take off tape on press, rack the dirty screens, then dip, pressure wash, scrub on 701, pressure wash, soft rinse, rack for drying, coat, and that's it.
I'll post pics of my hold down and draining rack for the tank soon.
oh, and post expose dunk tank is the absolute sh!t also. Would not go back to slow soaking with a hose ever.
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Thanks! :)