If someone has an answer for me i would appreciate it. my problem is this. i use ulano dual cure emulsion. the pink stuff. it is brand new, just put the sensitizer in 3 days ago. after i coat the screen i blow it with a dryer to speed things up, then burn for about 20 miutes and then wash it out. but the screen looks horrible when it washes. the small lines wont come out. the edges get jagged. do you guys thing i should let it sit over night before i burn it?
I like to let my screens dry of their own accord for at least 4-5 hours before I try to shoot them. It could be your shooting the screens before they are fully dried. I would also run and exposure calculator on your screen to ensure your hitting the correct exposure time. Dual cures are easier to dial in than photopolymers so this part shouldn't be difficult.
the small lines wont come out. the edges get jagged.
two things i can think of as the causes of small lines not coming off: over exposure.... and/or.... you probably "over-cooked" the emulsion when you blow-dried it.
jagged edges can be caused by over soaking during wash out. emulsion starts to soften and breaks from the edges.
try leaving your coated emulsion on a dark room to dry for few hours.
If someone has an answer for me i would appreciate it. my problem is this. i use ulano dual cure emulsion. the pink stuff. it is brand new, just put the sensitizer in 3 days ago. after i coat the screen i blow it with a dryer to speed things up, then burn for about 20 miutes and then wash it out. but the screen looks horrible when it washes. the small lines wont come out. the edges get jagged. do you guys thing i should let it sit over night before i burn it?
two words.....
OVER EXPOSURE
over exposure will close the fine lines and make it hard to wash out the screen...and the longer you wash out the screen the more the emulsion breaks down .....and the edges look like stairs or saw toothing...
my advice would be to try to let the coated screen dry with a fan on it for at least 4 hours..and if it is drying in a room with a lot of humdity then it will take longer..maybe even get a dehumidifier....then when you burn ..try to burn for no longer than 14 - 16 minutes...I use a dual cure emulsion and seem to get great results at the 15 minute mark.....
thanks. that seems like the problem. i also use vellum and run it through the printer. when i expose the screen the part that was under the vellum is not as dark as the rest of the screen. does that sound like it is under exposed or should it be ok. thanks for your help. I appreciate it
when i expose the screen the part that was under the vellum is not as dark as the rest of the screen.
that is how it is supposed to look...the different colors means the part that was under the vellum wasnt exposed and will wash out ..the darker parts of the screen means that part was exposed and shouldnt wash out. also make sure your vellum is dark enough to block out the uv light...I have heard of people using vellum and the vellum wasnt dark enough and had the same problems you are having now..if you need to print 2 vellums and tape them together to get a nice dark film.
thanks. that seems like the problem. i also use vellum and run it through the printer. when i expose the screen the part that was under the vellum is not as dark as the rest of the screen. does that sound like it is under exposed or should it be ok. thanks for your help. I appreciate it
Do you mean you get a ghost of where the full sheet of velum was placed on your screen (not just the black toner image you're burning, there should be a big difference between the two)?
This is normal, you will always notice a difference of where the vellum was on the screen as it's not 100% transparent film. This doesn't mean it will wash out tho, so don't worry.. you may get some pin holes tho.
Always try exposure test strips if you're having issues, it will narrow down the problems with exposure timing and washing.
have heard of people using vellum and the vellum wasnt dark enough and had the same problems you are having now..if you need to print 2 vellums and tape them together to get a nice dark film.
Inked
Not a bad idea but I wouldn't recommend that as you are also doubling up the vellum opacity. What i did when using vellum and the toner was running low and not making an opaque enough image, was to run it through the dryer. This re melts the toner and makes it much darker. this works great for a 1 color print but i don't recommend this for multicolor jobs as you will have issues registering multi color prints.
thanks this help clear up a lot of things. I want to thank you guys. its amazing how willing you all were to help me, so thanks. so i will let my screens air dry, and double the vellum
Get an exposure calculator/ step wedge guide and use it on every screen you expose. It'll save you countless headaches and time when trying to recalculate burn times. I hardly ever expose a screen without it. Mine's made by Saati. Imagemate is another. Only cost about $10 - $15. It calculates how much you need to increase or decrease the exposure time to make a perfect screen.
exposure and emulsion problems 
Re: exposure and emulsion problems 
