Post-exposure dip tank?

[jvanick]

I've heard a few people here talking about post-exposure diptanks...

I assume you're just using a standard tank with water in it instead of wetting the screens with a hose.

What's the pros and cons of doing this instead of the hose?

I have the opportunity to grab a tank for dirt cheap and was thinking it might make life easier...

[tonypep]

Yes some people do this. Obviously the water will pre-soften the exposed portions of the screen. Not a bad idea if you are not pressure rinsing. Can cause bottlenecks for some for others its a non issue.

[bimmridder]

Tony, here in our shop (and this is what works for us, not necessarily anyone else) we use a dip tank and pressure washer (750 psi). I've actually unintentionally left screens in the tank over night and still use pressure washer and have great screens. We do all our screens like this, from specialty screens (26tpi) to 4CP (355tpi). Not saying it will work for anyone else, but it does for us.

[screenprintguy]

Watching Bimmrider and Greg Kitsen doing this, we started doing it 2 years ago and it speeds up our process, as the wet softened image basically falls out in the wash out booth rather then standing there holding a hose or blasting with a pressure washer to soften the image. Its a great addition to our exposure process!

[tonypep]

Thats how we did it in St Thomas. One auto, 2 man shop. They would soak while presses ran.

[Gilligan]

My guy LOVES it... You can literally rub the image off with your fingers.

Only downside I see is that my guy leaves them in so long some emulsion is coming off in the tank... It just makes the water kind of gross, nothing else bad about it.

[GaryG]

Thats how we did it in St Thomas. One auto, 2 man shop. They would soak while presses ran.

Now there's a dream job!
Soaking in the tank, and soaking in the sun!!

In smaller shops like ours soaking is a multi-tasking benefit
while other tasks are being done.

[alan802]

We do it and although it's not technically faster, while the screen is soaking for a few minutes you're doing other tasks like Gary said.  Instead of standing there spraying the screen with the pressure washer, you can be burning more screens.  Some higher mesh screens with thin stencils will literally spray out with a spray bottle after soaking for a few minutes.  It's allowed us to hold a little more detail since very little pressure is needed to knock the stencil out and the finer halftones don't get blown out.  We can hold a few percentage points smaller in halftone dots by pre-soaking/post exposure.

[screenprintguy]

I get a nice flow going, doing 2 screens at a time, after they start coming off of the I-Image CTS, 2 go in the tri-light, supper fast to expose, go right in the water, pop 2 more screens in the tri-light, check my CTS, pop in a new screen there, hit print, tri-light's done, swap out the dunked screens, pop in two more frames in the tri-light, and keep on rockin. There is a cool shop in Tampa, Class B, they just moved into a new giiiiiiiinormise space, huge front of house, I didn't even get to see that, but the production manager took me on a shop tour. They run, if I can remember, 6 or 8 autos, they had at that time Sportsman ex's and some older lawsons, tons of small 24 piece orders. They  have a nice huge dedicated clean aired DTG room, and the Imaging room is to die for. A screen printers dream and a half. Totally sealed up, keep in mind all new construction, so it all looks really sweet too, like show room look there. In the imaging room, one girl running it, doing 200-300 screens a day on her own. She as a brand new kiwo CTS, brand new kiwo screen coater that coats, I think 4 frames at a time, everything is 23x31 there. Brand new Douthit cts exposure unit. I have a feeling, if Rich, hint hint hint, sent someone over there like Ron, hint hint, lol, they would swap out of that into a D-scan. And then finally they had this cool CCI stainless tank and rinse thing made. It can hold up to like 15 or 20 frames along these rails, you slide the exposed screens down in there and there is a foot pedal switch that activates an agitator, and at the far end is a rinse booth with just a hose and standard water pressure to rinse. This girl gets moving along and her system is very smooth. That big CCI thing though, is about 12 feet long, but with the agitated water, the images are just about gone when she lifts a screen for final rinse. I would think, an agitated tank alone, and then that new M&R auto rinse booth would be the bomb in that system, but like I said, it's a very impressive room that keeps 1 employee rocking busy 8 hours a day cranking out perfect screens. I must have seen 50 or so rolling screen racks full of newman frames, ready for production racks, and then post production ready for de-ink racks. Cool place and cool production manager to take me on a tour. I'd eventually love to have my Imaging room which is now my office desk and mac with my I-image, with an adjacent dark room for easy access screen storage expanded into a larger room with a D-scan in the room next to the CTS, and the Auto Rinse booth, maybe build a clean air de-humidifiying room to then put the rinsed screens for quick drying. That would be sweet!

[jvanick]

cool... I'm going to check it out later today... if it looks good, I'm buying, even if not, sounds like even a brand new one might not be too bad an idea..

[tonypep]

Brannon may have a used one.......lil bird told me

[ericheartsu]

we also do this. Like everyone else said, it just seems to help a bit.

We expose, put two screens in, set up the next screens in the exposure unit, and then rinse while it's exposing.

[screenprintguy]

We have a petroleum contractor customer that had a fiberglass tank that normally goes underground under gas pumps at the gas station that didn't fit on a job, and he gave it to us. It's a bit bigger than a standard dip tank, 100 gals, but it's perfect for the presoak, I have an air line weighted down at the bottom, and attached to a small air pump that agitates the crap out of the water, it's actually a bit too much, makes the water foam up lol, but when you pull out a screen, there is almost no emulsion left in the image area from the agitated water.

Hey guys using them, how often are you changing your water, I haven't changed ours in a while, dam near a year now, I put a cup of bleach in the water every friday night to keep the water from getting nasty, doesn't effect t he stencils at all, keep in mind it's 100 gals of water as well, but I imagine all of that unexposed emulsion eventually builds up in there. Plus with us using the CTS, the water immediately turned black from the ink coming off the image in the soak. Just curious.

[tancehughes]

We use one and it helps us multi task better, I highly recommend it. Doesn't hurt the screens if they stay overnight in the tank, although we don't make a habit of that.

[alan802]

I've been changing out the water every couple weeks.  Ours is a smaller unit that only fits two 23x31 screens so I can pick it up and drain it easily unlike the reclaiming dip tank that takes some serious muscle to move around.