Hello catspit users!

I have been using Ryonet WBP Hybrid Emulsion until I met with the owner of Saati chem who introduce me to his new PHU emulsion.

He gave me a pint to try out, while I just ordered a gallon anyways. I coat my screens 1/1, about 5 of them. Here's the kicker, when I went to go wash out my first screen, the emulsion literally just peeled right off!
I have been having so much problems with the phu emulsion but I want to use it as my main emulsion.

I do have a dehumidifier setup in my dark room. It stays at a steady pace of 44% humidity at 88 degs temp.

The screens were fully dried, I dont get how it just peels off.

The screen itself was cleaned off with franmer strip-e-doo, and degrease/dehaze with ryonet green stuff.

Heres the video:

http://www.youtube.com/watch?v=3B7uSrxX62s

Under exposure?

My first guess would be that the emulsion just isn't adhering well to the mesh, but you're degreasing using "green stuff" (same as what I currently use) so I don't think it's a problem with dirty mesh. I can't speak as to the humidity settings, since I don't have a way to check what humidity is like with my setup. The only other thing I can think of is maybe it's a combination of underexposure (do a step wedge test) and possibly too much water or pressure. Also, if this is a sample pint that had been lying around, it may just be old emulsion! I'd say once the new stuff arrives, do a step wedge test first thing and see if you get the same problems with that batch.

Update: Alright I took your advice big time. This time I exposed for 7:30 (in the video I exposed for 2:50). It was hell to wash out, I actually had to put my power washer on to wash it out (the spray nozzle was think about 3 inch spray over the screen).

It washed out without the problems from the video, but it wasnt clear. Many of the lines didn't have a straight look, some of the lines looked distorted. I did a quick print with black waterbased ink, the mesh is 156. (the video mesh was 230)

I notice when I was washing out the ink from the screen, that the emulsion started peeling from the corners again (like the video), I took some pictures. It wasn't peeling for the whole screen, just on the think end corner of the emulsion..

I'm happy that I'm making progress with this emulsion, I thank everyone for there continuous help.

Should I up the exposure more past 7:30? My last emulsion the wbp hybrid, my exposure time was at around 12:00.
And I forgot to include my step wedge test while exposing the screen, but from the details I hope you have an answer! lol

I would try someplace in between the 2 times you have tried. When I have exposure issues I adjust the time in smaller increments. 15-20 seconds more or less, depending on the situation. I would try around 3min 20 sec and make sure you have enough positive contact. I think the window on proper exposure time is pretty small but that depends on the exposure unit power being used. Just my thoughts.

Good to hear. Yeah, try exposing for 4-5 minutes and see what happens. Sounds like you're over exposing now. Too much time under water can cause detail lose.

Hmmm.... I'll add this:

Don’t forget using a pressure washer to force the emulsion out during washout will cause saw-toothing where the emulsion only adheres to the grid line of the mesh.

Also make sure to abrade the mesh if it is new. Use the thinner side of your scoop coater and try to coat the mesh with a little less emulsion.

The wrinkling and peeling in your video is due to poor emulsion to mesh adhesion and too much time in the washout booth.

I have been getting a lot of good feedback on this emulsion despite the issues presented here. It seems to be impressing a few people so it is now available through Catspit.

http://catspitscreenprintsupply.com/saa ... on-gallon/

A good friend of mine loves it so that is good enough for me Saati makes great emulsions.