we are having a real problem when it comes to coating screens we are using Ulano's QTX emulsion and when we coast the screens we end up with heavy and light areas no matter what, and when we go to burn the screens even at only 2 mins its not washing out..... we are using a scoop coater and have a Odessesy light box.
how are you exposing the screens? how strong is the light?
what mesh screens are you using? (110, 230, 305)?
are you coating both sides of the screen?
The first thing I can say is that you should definitely be exposing the screens for more than two minutes. You need to experiment.. Try 3 mins, 3.5 mins and so on.
Make sure your are in a light safe area, like a darkroom. The only UV light that is hitting your screen should come from your light box.
That's it for now.. I will post more when it comes to me.
if you are getting uneven coating with a scoop coater that is because you are not using even pressure as you go from up to down, are you applying a coat on both sides, or applying multiple coats? all of these factor into the process when you are applying the emulsion, if this continues to be a problem for you i suggest you switch to film emulsion which is much easier to apply and less mistake prone
what area are you coating your screens? you should be in a darkroom with onl a redlight or buglight....your emulsion may be getting hit by a uv light source and drying before you have a chance to expose it.
i have no idea about the light source you are using or what the wattage is or even the distance from the light to the screen but like van ink said you need to experiment alot of different ways to figure out your proper exposure time...and the amount of emulsion coating and the light source all factor into that eqaution
try and get a halftome strip from your screenprint supplier that will help in your various tests
First I make sure I am in a dark room with no daylight coming in. Hang extra material over your windows if needed and tape the ends to the wall to block all outside light out. In the darkroom you can use a low night light of some type or use the light in the hallway or another room with your darkroom door open so you can see what your doing. I coat my screens on each side evenly. Make sure your strokes are of even pressure.
I also lay a heavy sheet of glass on top of my screen and image and put a black poster board underneath the screen also. This blocks out light from coming up underneath.
We do need more info like what Van ink asks for. The outcome of your screen depends on certain variables. It most likely was because you under exposed it but it depends. I expose a 110 screen at about 5 mins depending upon the image.
um...this might be a stupid question but are you using a "light box" such as you would for tracing images or looking at photos? if so, that is not going to work.
how are you exposing the screens? how strong is the light?
what mesh screens are you using? (110, 230, 305)?
are you coating both sides of the screen?
The first thing I can say is that you should definitely be exposing the screens for more than two minutes. You need to experiment.. Try 3 mins, 3.5 mins and so on.
Make sure your are in a light safe area, like a darkroom. The only UV light that is hitting your screen should come from your light box.
That's it for now.. I will post more when it comes to me.
Hope this helps.
dulreich
We have 6 20watt uv fluorescent type bulbs its an Odsessy Brand
150 mesh and 180 mesh
1 to 1 wet coating (one coat each side)
with the emlusion that i have my sales rep tells me that it should be in the 2-3 min range with the QTX but im open for ideas
no lights in the room and windows are covered in yellow transprant vinyl
are you using the thin side of the coater? The uneven coats are due to what Steve mentioned as well as very loose mesh. As far as burning its possible you might need to replace your bulbs.
i use DLX emulsion and burn the screens with a 500w construction light with a 14 inch space between the light and screen. coat both sides and make sure to scrape again getting any extra emuslion. you dont want it to be thick you know. i leave the light on for 3 minutes
coating screens 
we are having a real problem when it comes to coating screens we are using Ulano's QTX emulsion and when we coast the screens we end up with heavy and light areas no matter what, and when we go to burn the screens even at only 2 mins its not washing out..... we are using a scoop coater and have a Odessesy light box.
Re: coating screens 
