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

[screenprintguy]

Thanks Tony! Have a great weekend man!

Mike

[Prosperi-Tees]

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.

Another DOH moment for me I was just confused cause it said wet on wet and then the flash came into olay

[screenprintguy]

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.

Another DOH moment for me I was just confused cause it said wet on wet and then the flash came into olay

sorry I should have clarrified. We would run a flash to keep boards warm, as I had been told by a few others that do w/b printing to give a kick start to the discharge. Our reno flashes woudn't reallly, "fully" flash cure w/b without burning the shirts so I was just always used to having a flash for a few seconds on head two, then all the rest wow. I'll make sure there is NO flash on at all from now on. =)

Just ordered a 5 gal of cci base and a 5 of cci white. Can't wait to try the base, i know the white is awesome!

[Prosperi-Tees]

I have CCIs base and white and like them alot. CCI is still a couple months away from having pigments so I'm most likely gonna go with Sericol system which is very good! And I like the ready mix colors.

[Itsa Little CrOoked]

I know this is an old thread, but I specifically want to see what has evolved with the build-up problem, cause I can't seem to stop this at all.  I am all manual, and when it happens, I just wipe it off the underside and I dislike that.

So Screenprintguy, please give us an update if/when you see this.

Thanks!
Stan

[RICK STEFANICK]

Under exposed screens can contribute to this also..

[Itsa Little CrOoked]

Under exposed screens can contribute to this also..

I can definitely see that.  I don't believe I'm underexposing, because I have had that problem in the past. I might try some post exposure, to make dead sure the stencil is hardened off.  Some say that doesn't do anything with certain emulsions, but I'm a bit foggy as to why.  I use either WR 25 or Ulano QT Discharge, both of which utilize Diazo, if that matters.

[jsheridan]

I'll put my money on the ink is the NEO series of matsui inks.. uses white in the mixes and makes the ink sticky. Always had a problem with buildup no matter if flashed or not. Didn't have that problem using PC mixing of pigments, it was when we started with neo system and using a lot of matte white in mixes, it started to build.

After using jantex for the last 6 months daily I have little to no buildup of colors as mixes use base and pigment with little to no white base.

[tonypep]

I'll touching on this in the PW article but try to refrain from using white at all in the formulas. John is right it will gum up the ink whether it is white or white PC. Less pigment or more binder should yield brighter colors. Mixing WB requires a different thought process. An excepiton is perhaps a lemon yellow on a garment that doesn't discharge great. In that case print this color last.

[JmanRT]

i use to run into this issue all the time, the solution for me was to add 5% water and 5% retarder to all my mixes. this doesn't effect the vibrancy of the color at all, in most cases it actually helps because of increased saturation. Last week i actually ran a 3 color 1150 piece run and didn't have a single issue with build up. there is a lot of variables that have to be considered though including the enviroment that your printing in

-Jeremiah