What would cause this to happen

[rmonks]

Emulsion Ulano LX-680 , I use Easyway 701 to remove ink power wash, then I dip in easyway Supra to remove stencil then power wash, re-apply 701 to remove any ink stain, rinse then degrease, vaccum water off screen place horizontal in rack to dry, coat with LX-680 two times on squeegee side once on other side, place in rack to dry. Note this is only happening on 110 and 83 mesh. Looks like the emulsion is maybe to thin and is forming like water droplets. What is your thoughts.

[Homer]

my first guess would be too much emulsion going down and it's drying fast enough.

[inkman996]

Did you say you coat twice on the squeegee side then once on the other? I hope you meant that in reverse.

I can't understand the diagonal run marks unless your screens are not perfectly flat while drying, or is their some kind of air flow blowing from that direction? Either way it looks like to much emulsion and gravity is winning the race.

[3Deep]

That screen looks nice and tight , but any chance that the mesh is loose, I've had that happen on some screen where the mesh is loose and too much emulsion on the screen cause it to leak down plus no air flow on the screen.

Darryl

[Croft]

didn't dry fast enough or at least tack up, I have a fan on low in my cabinet if its not turned on that happens here.

[alan802]

The lower mesh counts are too open to hold that much emulsion and that thin of an emulsion.  An 83 mesh will typically only need a 1/1 coating and even if the emulsion is a low solids content it can drip like that.  The streaks are new to me but look like the screen isn't drying horizontally. 

[GaryG]

Yes too much emulsion, not drying fast enough and are the streaks in the
direction you vacuumed?

Possibly contaminated nozzle somehow, or smearing degreaser
if not rinsed completely.

[JBLUE]

How many coats are on that thing?

[StuJohnston]

This sort of thing happened to me once, streaks and all. I can't say exactly why to be honest. I think it was because I forgot to degrease or forgot to rinse the degreaser out before coating. It was only a couple of screens thankfully, the next round was fine and so on.

[Inkworks]

Looks like it was coated normally, then sprayed with a garden hose briefly, propped on a corner up against a wall for 30-35 seconds, then put in a rack to dry.

In the future I'd forgo the post-coating garden hose spritz and go straight to the drying rack.

Seriously, I can't imagine what would cause that under normal conditions.

[Underbase37]

As others have said. It looks like to thick of a coat....looks to me like it started to drip/pool then a fan put on it moving the drips around. If you want a thicker stencil with that emulsion let it dry & put a few face coats on the substrate side.

Murphy37

[kirkage]

Too much emulsion. Been there, done that.

[Doug B]

  Definately too much. Even with an 83, I'll do a 2/2 but ALWAYS with the sharp edge of the coater.
With the dull side this will happen.

[rmonks]

Did you say you coat twice on the squeegee side then once on the other? I hope you meant that in reverse.

I can't understand the diagonal run marks unless your screens are not perfectly flat while drying, or is their some kind of air flow blowing from that direction? Either way it looks like to much emulsion and gravity is winning the race.

Yes that is the way I coated the screen, and the diagonal run marks I do not know why. The screens are setting on end until I vacuum the water off then. And the drying of the emulsion the screens are in a rack which is flat.

[3Deep]

Even though other's may say I'm wrong IMHO your not going to vac enough water off the screen to go straight to coating if your doing that, water has a way of hiding in crevice's and running down the screen when you least expect it (been there trying to hurry a screen).