Hi. I was wondering if there are some emulsions that just will not allow the UV rays from a 500 watt halogen worklight (with uv filtered glass face taken out of course) to penetrate it enough to allow a proper exposure??? the reason i ask is i have this emulsion i have yet to figure out. i was obviously paired up with an emulsion that didnt match my experience nor my equipment.(the supplier i bought it from pushed it on me even though he knew i was using a 500 watt halogen....geez i wonder why?? could it be cuz it was their companies brand emulsion...hhhmmmm i wonder.lol.) thats beside the point i am stuck with this emulsion and i already sensitived it so returning it is out of the question. so i tried how thick i coat my screen at first i used the rounded edge and coated t-shirt side twice than did the sqeedgee side once,and dried it with a fan on a medium setting for like 2 hours.,and exposed it with a step test but no step was fully cured it washed out most with a shower sprayer the rest with a pressure washer. i tried again this time only coating my screen with the sharp edge once on the t-shirt side and once on the sqeedgee side. let that sit in front of a fan for 4 hours this time and exposed it with a step test ,the first step starting at 10 minutes,and 3 minutes every inch after that. it all washed out with the pressure washer. i only needed stencil remover for the haze of emulsion left over. so maybe you guys can help me figure this one out first off "yes" it is winter here and "no" i dont have a dehumidifier. so i figured if i let it sit in front of a fan for 4 hours that would be plenty of time. i even went so far as to hit the screen with a hair dryer for a few minutes on both sides of the supposdly dry emulsion juist to eliminate the "surface" humidity that may have been present.i dont degrease my screens but they r brand new so i know it doesnt have toooo much grease (plus i am pretty sure my stencil remover has a degreaser in it anyways)on there but i read something the t-shirt guru "richard greaves" said once that degresing isnt that neccessary with direct emulsion. but honestly i dont think degreasing is the problem cuz years back when i used to silk screen shirts for profit i never degreased my screeens and i used the over and over again......so the emulsion was not pre sensitized but i mixed it up with the sensitizer till my arm was about to fall off so i dont know if that wopulbe be an issue at all, if by chance i didnt mix it up enough even though i am a man who has had many experince in such matters being into construction, painting , and other such activities. so am i not drying them long enough?? are there some emulsions that only require a very thin coat on just one side of the screen with just one pass of the scoop coater???? is there emulsion that just will not properly expose with a 500 watt halogen light source no matter how long i expose it(or longer than i have exposed it for being somewhere around 30 minutes)???? any emulsion that is fully exposed will "NOT" wash out with water no matter if you hit it with a pressure washer,or will it???? or is there just some emulsion that is so hard core that you "must" degrease after using it and our dear friend and mentor "richard greaves" dropped the ball on this one???? i am really in need of some sound advice cuz i have had this emulsion for a week now and have yet to print an actual print on a shirt. i dont like to waste money so i want to put this emulsion to use. so here are some facts that may help you figure out the problem. first off i just bought this emulsion a week ago.it is a Multi-Purpose Dual Cure Emulsion that says it has "exceptional exposure latitude and ease of decoating". this emulsuion was not pre sensitized and it is blue or bluish green in color. the company that supplies it is also the name of the emulsion so that is no use to you. on the side of it it says it contains "acrylates" what ever that is... the ingrediants are water (CAS#7732-18-5), polyvinyl acetate (CAS#9003-20-7), polyvinyl alcohol (CAS#9002-89-5) , TSRN80100215-5001P (trade secret), and acrylate monomer (trade secret). My light source is a 500 watt halogen work light i bought from lowes and i removed the from glass on the face of it. the light is suspended 18 inches above the screen and i have a couple layers of solid black t-shirts under the screen to prevent any reflections exposing the underside of the screen.there is no enclosure or box around it , it is just a light over a screen. i do also have a fan that blows over the screen at a low setting to prevent the screen from getting too hot from the amount of heat the 500 watt halogen produces. i use a 60 watt bug light i bought from lowes when i am coating my screens and i have blocked out an light from coming through my window even tho i only coat screens at night. i have not tried to burn a image on a screen yet (well ok once.lol it washed right out) i have just been trying to get the step test to show me something i can use to determine proper exposure time, but with no avail.the temperature in the room is not hot and not cold just comfortable. it does snow here. those are all the factors i can think of that may help you help me.lol. thank you for taking the time to read this. i know i included alot of stuff but i feel that is the only "true" way you can help determine my problem. thx in advance... and HEY!!! "Richard greaves"!!!! your input on this would be greatly appreciated i am pretty confident you could "shed some light" on the subject , no pun intended......ok maybe there was!!!!!
Last edited by Dretu Aliur; December 25th, 2008 at 02:52 PM.
I would stick to coating with the sharp side of the coater because you have a relatively weak light source. If you're having a hard time washing out even with a pressure washer, you may be over exposing. It's winter, so there's not a lot of humidity in the air-I presume- but if there is a lot of moisture where you're prepping your screens- it'll cause a problem.
More trial and error?
i appreciate your reply to my post. just to clarify i am not having a hard time wshing it out with a presuure washer i am having a problem keeping it "from" washing out. the longest i exposed a screen with a step test was somewhere around 30-35 minutes it shouldnt take that long even with a thin coat once on each side with the sharp edge of my coater i dont think. i never had problems in the past with exposure time and emulsion with a 500 watt halogen although i did make a box for it that was lined with tin foil with the light resting on top of it shining from above at about the same distance i have now which is 18 inches. i dont think an enclosure is the problems beings that i have seen videos where people have exposed screens for less than ten minutes with the exact set up i am using now.
When I had the exposure set up you are speaking of my light source was 12 inches away from the screen. I used a QX3 emulsion and it took approximately 8 minutes to expose the screens. I only coated once on each side using the sharp edge of the scoop coater. From reading your post the only two differences in my set up and yours is the distance from the screen and the emulsion. The distance should not cause the problem you are describing. It will just take longer to expose. 500w halogen units that are sold at Screenprinting supply stores as a kit are 21 inches from the screen and it takes about 18-23 minutes to expose a screen. My guess would be that you got a bad batch or old emulsion. I had a similar problem where I bought emulsion and the same day all of my screens washed out. I ran to a print shop near me that helps me sometimes to get his opinion on it and when he tried the same thing, the emulsion washed out. This shop has been in business for 47 years so I trust his opinion and he determined that the problem was the emulsion. He gave me the number to a local supplier he uses and I never had the problem again.
i appreciate your reply to my post. just to clarify i am not having a hard time wshing it out with a presuure washer i am having a problem keeping it "from" washing out. the longest i exposed a screen with a step test was somewhere around 30-35 minutes it shouldnt take that long even with a thin coat once on each side with the sharp edge of my coater i dont think. i never had problems in the past with exposure time and emulsion with a 500 watt halogen although i did make a box for it that was lined with tin foil with the light resting on top of it shining from above at about the same distance i have now which is 18 inches. i dont think an enclosure is the problems beings that i have seen videos where people have exposed screens for less than ten minutes with the exact set up i am using now.
i appreciate all your replies. i could still use more.so basically yes if it washes out burn longer . so i guess my fear is what will ahppen if i over epose it like by alot. i was think since it could expose for 30 minutes i would start the step test at 30 minutes and move an inch every 3 minutes. so tell me this if emulsion is properly exposed it will not i repeat will not spray out even with a pressure washer????? cuz if thats the case i will over expose that f-ing emulsion till it begs for mercy and hit it with my pressure washer and spray that son of a b-word as much as i want and it wont spray out. right????
Start by reading the FAQ I have on the Ulano web site about hardness being the first responsibility of the screen maker. The stencil has to survive the development process before you can expect to use it for printing.
Measure your exposure with a Stouffer 21 Step Transmission Guide photo positive. 5.5 inches. Expose so a solid step 7 SURVIVES washout. You can then fiddle with your exposure amounts and get visible feedback like learning to shoot a machine gun. Ready Fire Aim! The 21 step doesn't care what lamp you use, it only cares when you reach a volume amount of UV energy. Low energy lamps just take longer.
How long does it take to fill a gallon bucket with water? With a medicine dropper - 2 hours. With a fire hose - 2 seconds. It's still 1 gallon! Time is relative.
Water resistant stencils require completely cured/hardened exposure be cause the ink itself has the solvent that can break down the stencil - water.
Overexposure
The sensitizer in emulsions cross link and change the stencil into something that will not dissolve in water and rinse down the drain. After a certain amount of UV energy exposure, the stencil has no more sensitizer to cross link, so what's the point of exposing any longer?
Shops with inferior positives that don't stop UV energy should worry because they will allow a mild 'crust' to form on the surface of the stencil where the positive failed.
Search these forums for "21 step" or "Stouffer" and especially "dime". If you put a dime or aluminum foil on the stencil, you can expose for hours and you will just be spending your time watching nothing happen.
When UV energy lands on a positive at an angle it will CHOKE small lines and dots. You can't stop it except to compensate by anticipating and making fine lines fatter. You can fool yourself by under exposing the stencil but at the cost of durability and making the stencil harder to reclaim. Yes. Harder to reclaim.
I will read all these long posts after dinner and reply later.
__________________
How are you measuring? retired Ulano Technical Support Screen printing since 1979 - SGIA Academy Member
I just thought of something else. This may have been mentioned in your post but it was so long I just couldn't bare to read it again. But I just thought about the vellum you may be using. Sometimes when the vellum isn't dark enough it will allow light to pass through causing all the emulsion to wash out.
Something to check. If you did mention this then sorry for the post otherwise make sure the image is very dark.
I just thought of something else. This may have been mentioned in your post but it was so long I just couldn't bare to read it again. But I just thought about the vellum you may be using. Sometimes when the vellum isn't dark enough it will allow light to pass through causing all the emulsion to wash out.
Something to check. If you did mention this then sorry for the post otherwise make sure the image is very dark.
Katrina
What does Vellum look like? Is it a transparency film as well? Im a little confused on this, i heard the name before, but don't know what it is...
p.s Im a newbie at Screenprinting so have patience on me. lol
Last edited by ambitious; December 26th, 2008 at 05:52 PM.
Reason: unfinished sentence
I was wondering if there are some emulsions that just will not allow the UV rays from a 500 watt halogen worklight (with uv filtered glass face taken out of course) to penetrate it enough to allow a proper exposure???
the reason i ask is i have this emulsion i have yet to figure out.
As much as I like work quartz halogen lamps with their APPROXIMATELY 27% IR energy, 3% UV energy and 70% visible energy - How do you know there is any UV energy in your bulb? It may be one of the many UV resistant coated bulbs.
Quote:
Originally Posted by Dretu Aliur
i was obviously paired up with an emulsion that didnt match my experience nor my equipment.(the supplier i bought it from pushed it on me even though he knew i was using a 500 watt halogen.... geez i wonder why??
could it be cuz it was their companies brand emulsion...hhhmmmm i wonder.lol.) thats beside the point
Which emulsion? What distributor? Is it a slow emulsion or a fast emulsion. If you added diazo, that is always a slower exposing emulsion.
Quote:
Originally Posted by Dretu Aliur
i am stuck with this emulsion and i already sensitived it so returning it is out of the question. so i tried how thick i coat my screen at first i used the rounded edge and coated t-shirt side twice than did the sqeedgee side once,and dried it with a fan on a medium setting for like 2 hours.,and exposed it with a step test but no step was fully cured it washed out most with a shower sprayer the rest with a pressure washer.
How long were the steps?
Dry is very important to me, but not at the top of the list. If the surface is dry, UV energy will harden it and it and you will see it in development.
Quote:
Originally Posted by Dretu Aliur
i tried again this time only coating my screen with the sharp edge once on the t-shirt side and once on the sqeedgee side. let that sit in front of a fan for 4 hours this time and exposed it with a step test ,the first step starting at 10 minutes,and 3 minutes every inch after that. it all washed out with the pressure washer. i only needed stencil remover for the haze of emulsion left over.
So you know with that mystery diazo emulsion, 20? minutes isn't enough exposure. Do you trust the emulsion, or the lamp? You need to find out if the emulsion works. If it is sunny outside, you can use the sun make a pass/fail test and see if it can harden your mystery emulsion.
Quote:
Originally Posted by Dretu Aliur
so maybe you guys can help me figure this one out first off "yes" it is winter here and "no" i dont have a dehumidifier. so i figured if i let it sit in front of a fan for 4 hours that would be plenty of time. i even went so far as to hit the screen with a hair dryer for a few minutes on both sides of the supposdly dry emulsion juist to eliminate the "surface" humidity that may have been present.
i dont degrease my screens but they r brand new so i know it doesnt have toooo much grease (plus i am pretty sure my stencil remover has a degreaser in it anyways)on there but i read something the t-shirt guru "richard greaves" said once that degresing isnt that neccessary with direct emulsion.
but honestly i dont think degreasing is the problem cuz years back when i used to silk screen shirts for profit i never degreased my screeens and i used the over and over again......so the emulsion was not pre sensitized but i mixed it up with the sensitizer till my arm was about to fall off so i dont know if that wopulbe be an issue at all, if by chance i didnt mix it up enough even though i am a man who has had many experince in such matters being into construction, painting , and other such activities. so am i not drying them long enough??
Degreasing will not effect exposure, but it will effect the surface tension of liquids like emulsion on the mesh. If you saw fish eyes, which will lighten the emulsion coating and effect your deposit. That's a reason to degrease for emulsion. Let's put that aside for this problem.
Quote:
Originally Posted by Dretu Aliur
are there some emulsions that only require a very thin coat on just one side of the screen with just one pass of the scoop coater????
is there emulsion that just will not properly expose with a 500 watt halogen light source no matter how long i expose it(or longer than i have exposed it for being somewhere around 30 minutes)????
Emulsion for textiles is very different from graphics where metal, glass & plastic don't absorb ink. A piece of photocopy paper is a fabulous stencil if you cut a Valentine heart in it, because it is on the bottom of the mesh like capillary film.
Emulsion is usually ?38% solids which means 62% water. The stencil shrinks as the water leaves and takes on the shape of the mesh and pulls into the mesh so it looks like a waffle. The stencil is in the mesh, not a film on the bottom of the mesh.
Quote:
Originally Posted by Dretu Aliur
any emulsion that is fully exposed will "NOT" wash out with water no matter if you hit it with a pressure washer,or will it????
Yes a pressure washer can remove most stencils without chemical stencil remover. Properly exposed, most stencils should dissolve water and rinse down the drain.
Quote:
Originally Posted by Dretu Aliur
or is there just some emulsion that is so hard core that you "must" degrease after using it and our dear friend and mentor "richard greaves" dropped the ball on this one????
Answered above.
Quote:
Originally Posted by Dretu Aliur
first off i just bought this emulsion a week ago.it is a Multi-Purpose Dual Cure Emulsion that says it has "exceptional exposure latitude and ease of decoating". this emulsuion was not pre sensitized and it is blue or bluish green in color. the company that supplies it is also the name of the emulsion so that is no use to you. on the side of it it says it contains "acrylates" what ever that is... the ingrediants are water (CAS#7732-18-5), polyvinyl acetate (CAS#9003-20-7), polyvinyl alcohol (CAS#9002-89-5) , TSRN80100215-5001P (trade secret), and acrylate monomer (trade secret).
Dual-cure emulsions that use diazo are not known for their speed, but their resolution.
Quote:
Originally Posted by Dretu Aliur
My light source is a 500 watt halogen work light i bought from lowes and i removed the from glass on the face of it. the light is suspended 18 inches above the screen and i have a couple layers of solid black t-shirts under the screen to prevent any reflections exposing the underside of the screen.
Good.
Quote:
Originally Posted by Dretu Aliur
there is no enclosure or box around it , it is just a light over a screen. i do also have a fan that blows over the screen at a low setting to prevent the screen from getting too hot from the amount of heat the 500 watt halogen produces.
Good.
Quote:
Originally Posted by Dretu Aliur
i use a 60 watt bug light i bought from lowes when i am coating my screens and i have blocked out an light from coming through my window even tho i only coat screens at night.
OK.
Quote:
Originally Posted by Dretu Aliur
i have not tried to burn a image on a screen yet (well ok once.lol it washed right out) i have just been trying to get the step test to show me something i can use to determine proper exposure time, but with no avail.
Do you see color changes? Proof of ANY exposure?
Quote:
Originally Posted by Dretu Aliur
the temperature in the room is not hot and not cold just comfortable. it does snow here.
Quote:
Originally Posted by Dretu Aliur
those are all the factors i can think of that may help you help me.lol. thank you for taking the time to read this. i know i included alot of stuff but i feel that is the only "true" way you can help determine my problem.
Quote:
Originally Posted by Dretu Aliur
thx in advance... and HEY!!! "Richard greaves"!!!! your input on this would be greatly appreciated i am pretty confident you could "shed some light" on the subject , no pun intended......ok maybe there was!!!!!
I want you to try a sample of a pre-sensitized faster emulsion & the sun, because I know it has plenty of UV.
If the Lot Number is less than a year old for the diazo, it is pretty hard to screw up stirring in the diazo, it just takes time.
Blatent Plug: Get a sample quart of Ulano QLT. Almost as fast as QTX, way better solvent resistance and resolution AND US$35 less expensive per gallon. Pre-Sensitized so never mix, never worry, never stir.
__________________
How are you measuring? retired Ulano Technical Support Screen printing since 1979 - SGIA Academy Member
Last edited by RichardGreaves; December 26th, 2008 at 06:23 PM.
Hi. I was wondering if there are some emulsions that just will not allow the UV rays from a 500 watt halogen worklight (with uv filtered glass face taken out of course) to penetrate it enough to allow a proper exposure??? the reason i ask is i have this emulsion i have yet to figure out. i was obviously paired up with an emulsion that didnt match my experience nor my equipment.(the supplier i bought it from pushed it on me even though he knew i was using a 500 watt halogen....geez i wonder why?? could it be cuz it was their companies brand emulsion...hhhmmmm i wonder.lol.) thats beside the point i am stuck with this emulsion and i already sensitived it so returning it is out of the question. so i tried how thick i coat my screen at first i used the rounded edge and coated t-shirt side twice than did the sqeedgee side once,and dried it with a fan on a medium setting for like 2 hours.,and exposed it with a step test but no step was fully cured it washed out most with a shower sprayer the rest with a pressure washer. i tried again this time only coating my screen with the sharp edge once on the t-shirt side and once on the sqeedgee side. let that sit in front of a fan for 4 hours this time and exposed it with a step test ,the first step starting at 10 minutes,and 3 minutes every inch after that. it all washed out with the pressure washer. i only needed stencil remover for the haze of emulsion left over. so maybe you guys can help me figure this one out first off "yes" it is winter here and "no" i dont have a dehumidifier. so i figured if i let it sit in front of a fan for 4 hours that would be plenty of time. i even went so far as to hit the screen with a hair dryer for a few minutes on both sides of the supposdly dry emulsion juist to eliminate the "surface" humidity that may have been present.i dont degrease my screens but they r brand new so i know it doesnt have toooo much grease (plus i am pretty sure my stencil remover has a degreaser in it anyways)on there but i read something the t-shirt guru "richard greaves" said once that degresing isnt that neccessary with direct emulsion. but honestly i dont think degreasing is the problem cuz years back when i used to silk screen shirts for profit i never degreased my screeens and i used the over and over again......so the emulsion was not pre sensitized but i mixed it up with the sensitizer till my arm was about to fall off so i dont know if that wopulbe be an issue at all, if by chance i didnt mix it up enough even though i am a man who has had many experince in such matters being into construction, painting , and other such activities. so am i not drying them long enough?? are there some emulsions that only require a very thin coat on just one side of the screen with just one pass of the scoop coater???? is there emulsion that just will not properly expose with a 500 watt halogen light source no matter how long i expose it(or longer than i have exposed it for being somewhere around 30 minutes)???? any emulsion that is fully exposed will "NOT" wash out with water no matter if you hit it with a pressure washer,or will it???? or is there just some emulsion that is so hard core that you "must" degrease after using it and our dear friend and mentor "richard greaves" dropped the ball on this one???? i am really in need of some sound advice cuz i have had this emulsion for a week now and have yet to print an actual print on a shirt. i dont like to waste money so i want to put this emulsion to use. so here are some facts that may help you figure out the problem. first off i just bought this emulsion a week ago.it is a Multi-Purpose Dual Cure Emulsion that says it has "exceptional exposure latitude and ease of decoating". this emulsuion was not pre sensitized and it is blue or bluish green in color. the company that supplies it is also the name of the emulsion so that is no use to you. on the side of it it says it contains "acrylates" what ever that is... the ingrediants are water (CAS#7732-18-5), polyvinyl acetate (CAS#9003-20-7), polyvinyl alcohol (CAS#9002-89-5) , TSRN80100215-5001P (trade secret), and acrylate monomer (trade secret). My light source is a 500 watt halogen work light i bought from lowes and i removed the from glass on the face of it. the light is suspended 18 inches above the screen and i have a couple layers of solid black t-shirts under the screen to prevent any reflections exposing the underside of the screen.there is no enclosure or box around it , it is just a light over a screen. i do also have a fan that blows over the screen at a low setting to prevent the screen from getting too hot from the amount of heat the 500 watt halogen produces. i use a 60 watt bug light i bought from lowes when i am coating my screens and i have blocked out an light from coming through my window even tho i only coat screens at night. i have not tried to burn a image on a screen yet (well ok once.lol it washed right out) i have just been trying to get the step test to show me something i can use to determine proper exposure time, but with no avail.the temperature in the room is not hot and not cold just comfortable. it does snow here. those are all the factors i can think of that may help you help me.lol. thank you for taking the time to read this. i know i included alot of stuff but i feel that is the only "true" way you can help determine my problem. thx in advance... and HEY!!! "Richard greaves"!!!! your input on this would be greatly appreciated i am pretty confident you could "shed some light" on the subject , no pun intended......ok maybe there was!!!!!
Yes, some emulsions will not ever expose with your lamp. Yes, especially new screens, need to be degreased. If everything washed out then you didn't crosslink the emulsion. Most emulsion manufacturers have an 800 to call for support and a list of recommended bulbs to use with their emulsions.Move the light closer and see if you have any better results. If not, you have the wrong emulsion for your lamp. Over the last forty years I have used plenty of different lamps and emulsions. The process is pretty simple and straightforward. Are you sure you sensitized it properly? Was it a powder or syrup?
As much as I like work quartz halogen lamps with their APPROXIMATELY 27% IR energy, 3% UV energy and 70% visible energy - How do you know there is any UV energy in your bulb? It may be one of the many UV resistant coated bulbs.
Which emulsion? What distributor? Is it a slow emulsion or a fast emulsion. If you added diazo, that is always a slower exposing emulsion.
How long were the steps?
Dry is very important to me, but not at the top of the list. If the surface is dry, UV energy will harden it and it and you will see it in development.
So you know with that mystery diazo emulsion, 20? minutes isn't enough exposure. Do you trust the emulsion, or the lamp? You need to find out if the emulsion works. If it is sunny outside, you can use the sun make a pass/fail test and see if it can harden your mystery emulsion.
Degreasing will not effect exposure, but it will effect the surface tension of liquids like emulsion on the mesh. If you saw fish eyes, which will lighten the emulsion coating and effect your deposit. That's a reason to degrease for emulsion. Let's put that aside for this problem.
Emulsion for textiles is very different from graphics where metal, glass & plastic don't absorb ink. A piece of photocopy paper is a fabulous stencil if you cut a Valentine heart in it, because it is on the bottom of the mesh like capillary film.
Emulsion is usually ?38% solids which means 62% water. The stencil shrinks as the water leaves and takes on the shape of the mesh and pulls into the mesh so it looks like a waffle. The stencil is in the mesh, not a film on the bottom of the mesh.
Yes a pressure washer can remove most stencils without chemical stencil remover. Properly exposed, most stencils should dissolve water and rinse down the drain.
Answered above.
Dual-cure emulsions that use diazo are not known for their speed, but their resolution.
Good.
Good.
OK.
Do you see color changes? Proof of ANY exposure?
I want you to try a sample of a pre-sensitized faster emulsion & the sun, because I know it has plenty of UV.
If the Lot Number is less than a year old for the diazo, it is pretty hard to screw up stirring in the diazo, it just takes time.
Blatent Plug: Get a sample quart of Ulano QLT. Almost as fast as QTX, way better solvent resistance and resolution AND US$35 less expensive per gallon. Pre-Sensitized so never mix, never worry, never stir.
Blatant plug...use Sericol Dirasol 916 dual cure and their HD Heavy Duty Degreaser...very easy to expose and reclaim
1-800-SERICOL
What does Vellum look like? Is it a transparency film as well? Im a little confused on this, i heard the name before, but don't know what it is...
p.s Im a newbie at Screenprinting so have patience on me. lol
Yes the transparency. There are many different types, I use to use Casey's vellum with a Konica laser printer and the films were not dark enough and the company's response was to spray the vellum / transparency with this special spray that makes them darker. Of course that would be added costs so I just switched to a different type.
I am not the expert at sensitizing emulsion, but I was told to give my screens a 6 hour drying time. Even if you use a fan to get rid of moisture (and that may not help the situation), maybe your emusion has not had the time to setup properly. I use the lazy way and buy my emulsion ready to go. But then again I am small time, and only been doing this for a short time compared to the many experts available here. Good Luck
Emulsion vs. 500watt Halogen 
Re: Emulsion vs. 500watt Halogen 
Re: Emulsion vs. 500watt Halogen 
