Preventing "cakeey build up" when printing wet on wet discharge prints?

[screenprintguy]

We have nailed down our exposures, emulsion, tape, block out ect, doing some awesome multi color discharge prints, but, but, but, we are still battling the cakeey build up from doing wet on wet prints. Has anyone found a way to prevent this in the mix, an additive, or is it just making a point to stop every 30 or so prints and wipe the screen building up the most? The additives that we use in our Matsui mixes are printgen 3% and Fixer en 3%. DanK if you are out there, I'd love to hear you chime in as you guys are like the kings of discharge printing out there at Forward Printing.

Mike

[tonypep]

I use CCI base and Oasis PC and or Sericol. No additives. No build up

[screenprintguy]

now that's interesting. Is the build up a Matsui issue?

[tonypep]

Impossible to say based on all the interdependent variables but perhaps.

[screenprintguy]

so far, any discharge we've done so far has been matsui bright base, using matsui activator, matsui pigments, and matsui printgen, and fixer en. After about 20-30 prints, depending if double or single stroked, start to build up a cakeeyness when doing wet on wet. I have switched over to CCI white as that stuff smokes the Matsui. I just canceled an re-order on a 5 gallon of matsui base, and will try the CCI base and see if that eliminates the issue. If not, then it may be the pigments, since you aren't using any matsui pigments, maybe their pigments dry up fast on the back sides of the screens. All in all, the Matsui product is still nice in the end, but with all the time consuming issues, the least amount of time we can have that stuff sitting the the screens the better right.

[tonypep]

Rick turned me on to the Sericol RFU you should look into it. You can download the Pantone starter formulas. No pigments!

[screenprintguy]

Thanks Tony, we are willing to try new things. Anything to make it easier!

[Homer]

I got the same thing with matsui.  . .my emulsion was underexposed, so when the wet ink touched the screen,the emulsion became gummy, continually picking up ink with every pass making a hell of a mess under my screen -atleast that's what I think happens. I switched emulsion so we didn't have it dialed in good enough. We just ran 500 red anvil 779, matsui white @ 20%, 80% base and we didn't have that issue. Maybe check your exposure times again?

I do have sericol here too, we ran that on a job right after to see the difference. . Rick was right all along. try it out, atlas sells it if you need to buy some.

[ebscreen]

We will get a little build up if we stop for ten minutes or so and then start again.
The ink already on the shirts dries up a bit and starts to get a little sticky. Not noticeable
on the other end of the dryer, and clears itself up as long as we keep running.

So... keep moving.

[screenprintguy]

@ Homer, yeah it's definitely not the emulsion. we have that dialed in like stainless steel, it's a matter of wet on wet just building up. I had that issue last year until we started using Ulano 925 wr emulsion, now our stencils for w/b printing are perfect. Just trying to iron out this wet on wet build up. Do ya'll think maybe the heat build up from flashing could be causing? It's not so much of a wet build up, as when you get under there and wipe, more like scrape the build up off, it's actually dry build up.

[screenprintguy]

We will get a little build up if we stop for ten minutes or so and then start again.
The ink already on the shirts dries up a bit and starts to get a little sticky. Not noticeable
on the other end of the dryer, and clears itself up as long as we keep running.

So... keep moving.

Not from stopping, just happening after running solid. I'm wondering if it's from heat build up on the boards from flashing.

[Prosperi-Tees]

Flashing will for sure give you problems. I am assuming your flashing the base? You would need to be sure it is cooling down enough to hit it with the top colors or you will definitely have some drying issues.

[tonypep]

Well if you're printing WOW pigmented discharge colors the a base is totally unnecessary. I never flash discharge unless plastisol is printing on a DC base. Thats definitely the problem......or my best guess I should say. You should never need to flash btwn colors. Heat is your enemy here.

[screenprintguy]

I don't see the need to print a discharge under base, if all of the other colors printed are discharge mixed already, I've tried and felt it just added another element of aggravation.

So Tony, we should ,"not" flash from color to color doing wow multi color discharge print? Just want to clarify.

Thanks Man

[tonypep]

Absolutely not I've never even tried. BTW just try to keep any reds last or later in sequence for maximum pop. Don't ask me why.
Have a great wknd everyone looks like I actually don't have to be here!