can't get image, new emulsion, washout terrible, help!!
I have used speedball emulsion for the past month or so that I have had my shop in operation. . . it took twelve minutes on my homemade exposure unit, and usually had good results. . . . recently, after running out of the speedball variety, i purchased some Holden's Dual Cure photo emulsion, yellow stuff, real thick.. . i coated thee screens with it on Wedesday. . . yesterday, thursday, i observed the screens because i needed to start burning images. . they all looked wet in spots, i took the one that was the dryest, and exposed it, the image showed up pretty lightly when i sprayed it with water before going outside, but emulsion washed out all over the place once i sprayed it with a little pressure. . .
Today, friday, I just got done exposing a screen for twelve minutes, the design showed up before i even got it wet, I still sprayed it and waited for a short while, took it outside. . . i began to spray it at about the pressure it would usually take, maybe a touch softer, but only one little chunk washed out of one of the letters in the design, so I sprayed harder, now the design began to wash out, and mostly in the right spots, except some edges were a little jagged. . . still, many spots were not washing out, so I sprayed a bit harder again. . now, more of the design washed out, but there were also chunks coming out of the emulsion in other spots (not the design). . . . still, there were spots in the design, where it was supposed to wash out, that didn't, and I also found it weird that a couple of streaks that washed out were actually where the water that I sprayed on the screen before taking it outside ran down. . . that really confuses me!
has anyone else used the Holden's brand emulsion? anything I need to know?
what can i try? does this indicate anything that I'm not seeing to any of you? tips? help?
Re: can't get image, new emulsion, washout terrible, help!!
Make sure the emulsion is dry- put a fan on the screens. Expose longer. Soak screens with water after exposing- let sit for a few minutes- spray out. Hope that helps.
Re: can't get image, new emulsion, washout terrible, help!!
Washed out emulsion is a sign of under exposure. Because the emulsion is so thick, are you laying it down too thick? Do you have a scoop coater or something else?
What type of lighting do you have in your exposure unit?
Re: can't get image, new emulsion, washout terrible, help!!
I had that problem many times, one time with a dual part emulsion i forgot to add the water needed to the powder. After I did that it worked great. Just a thought.
Pat
Re: can't get image, new emulsion, washout terrible, help!!
alright, well i kinda took the weekend off, so the last screen that i coated almost a week ago now, i would like to get a time with today. . . not sure how far up i will go with the time, but the image burned on the last one, so I don't want to go up too much, cause some of the spots where the image was were hard to squirt out as well. . . i am going to try and find something to use for soaking the screen before i take it to wash, cause i have to go outside for that. . .
about the two part emulsion thing. . . it just told me to dissolve the powder in a small cup of cold water then mix. .. . there were some little peices of powder that got stuck to the bottom, and do you have any idea how much water you are actually supposed to use. . . it was a pretty small cup i used (like one i use in my kitchen for dipping sauces or something), and I have a quart of this, maybe i just need to add a couple drops more water or something? dont know how that would help but never know?
has anyone else ever heard of/dealt with this Holden's brand dual cure photo emulsion? Anything you know?
I definitely need to start producing shirts again in the next couple days here!
Re: can't get image, new emulsion, washout terrible, help!!
also, i have a scoop coater, but the emulsion did seem to go on really thick, well even seemed to be a little thicker than the diazo emulsion i had before. . .
i have a homemade light unit with a reg. sylvania halogen that i believe it 200w. . . i have been using this one with good results for a month or so now with the diazo emulsion. . .
Re: can't get image, new emulsion, washout terrible, help!!
At first I used Speedball emulsion too, exposed for 25 minutes or thereabout with a 150 watt bulb. Then I got some professional emulsion and my exposure time went up to 84 minutes! That Speedball emulsion exposes fast, so don't be afraid to really experiment, double your exposure and try to burn. Like others have said, you definitely need to expose longer, perhaps much longer.
Re: can't get image, new emulsion, washout terrible, help!!
If you have to burn for anything like 80 minutes, it's time to get any kind of light other than the one you're using- heck the sun would be 100% better. Get a step wedge or experiment with exposure times- there is no shortcut.
Re: can't get image, new emulsion, washout terrible, help!!
Did I understand you right--that you take it outside to wash it out??? How long do you let it expose in the sun before you wash it?? This may be part of your problem.
Re: can't get image, new emulsion, washout terrible, help!!
I was having the same problem for a long time with my screens. I fixed it quickly with a dehumidifier. I built a screen box that is light and air tight and my drying time went from 2 hrs to 10 minutes. The key is getting all of the water out of the emulsion. Also, I don't have a light-tight room for my exposure or washout. I expose with all of my regular lights on, and I take my exposed screens outside to washout and I never have problems. You just need to make sure that you work quickly. Just some insight.
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Re: can't get image, new emulsion, washout terrible, help!!
alright, thanks guys for all the input. . . weird thing happened. . .
but first, usually, i just do my exposing and washing out at night when i get home so the sun is not really an issue, and i have a bug light down in my shop. . . also, when i do go outside when it is light out, i spray the screen down with water, and let it sit for a while, i am working on a tub for soaking, but then i take it outside in a heavy duty garbage bag so that the sun doesn't get to it. . .
here the weird thing. . . i recoated all my screens with the new emulsion. . . still thought it was going on pretty thick, so i took some time tipping the screen back and going upward with my scoop coater, a lot of emulsion came off, and the coat looked a lot smoother. . . dried for one day, and looked good, so i did a test step wedge with four minute increments being at 16 20 24 and 28 min., washed the screen out, and couldn't tell any difference from top to bottom besides the very bottom (16min spot) where there wasn't a design had a little washout. . . otherwise, !!The design burned perfectly?? I am going to make a shirt with the screen. . . this seemed pretty odd to me, but if I can just put it around 24 minutes or something and get those results, great, all of the edges looked wonderful. ..
Re: can't get image, new emulsion, washout terrible, help!!
im getting very aggravated, as that emulsion has still stopped me from producing more than one shirt in the last two or three weeks. . . after that test step wedge that actually turned out perfect, i thought i had it figured out, but now. . . i tried making two more screens, exposing one for 25 then the other for 45 minutes! and still having washout problems. . . when i took either screen off of my exposure unit, you could already clearly see the design, like it was actually burnt into the emulsion. . . 25 min. screen. . . i was washing out, at night, and most all of the design washed out good, just when i was rinsing some of the emulsion off to make sure i had none drying in the openings later, i noticed a little extra washout around the first word of the text. . . a sprayed at it a little bit more. . . more came out. . . i kept spraying, not even at very high pressure, and the entire design proceeded to washout. . . strangely also. . . the part that didn't have the vellum covering it, cause i have bigger screens than i do a printer, didn't wash out at all, there was a definite line where you could tell where the paper was too. . . today i was washing out the screen that I exposed for fourty five minutes, and just had some of the same stuff, well washing out of emulsion around the letters usually at first, but then it always keeps going and such once it starts. . . it getting bubbly and stuff sort of too when it it coming off. . . i really need some help here boys. . .
is this still just a simple case of underexposure? how long am i going to have to expose? cheap alternative light that could speed up the process?
(usually 200w halogen currently) model name/number if you do have a bulb suggestion? could it just be a bad quart of emulsion?
Re: can't get image, new emulsion, washout terrible, help!!
I don't understand. you say you did a step wedge test and it came out to where you were able to determine your optimal exposure time. Then you expose two more screens with exposure times 20 minutes apart? What gives? What did the test show as your exposure time???????
can't get image, new emulsion, washout terrible, help!! 
Re: can't get image, new emulsion, washout terrible, help!! 
Re: can't get image, new emulsion, washout terrible, help!! 
Re: can't get image, new emulsion, washout terrible, help!! 
Re: can't get image, new emulsion, washout terrible, help!! 
Re: can't get image, new emulsion, washout terrible, help!! 
