Memphis Tennessee, 2:00 in in the afternoon, 110, 155, 230 mesh, WBP emulsion from Ryonet, 1:30 to 1:45. Most of the designs have halftones 45 to 50 lpi. This was done as an experiment, did about 20 screens and had excellent results. The 500 watt light 18" above the screen 23 minutes same screens and emulsion. I might add I use black foam inside the screen and a piece of glass over the film positive. What can I say it works! Ever see the movie "Reefer Madness".
Thanks, glad you enjoyed the video. But don't get me wrong. Some people do use the sun to expose and after many years they become good at it. Like sign shops who make very large screens. The point of the video here is an exposure unit will be easier to use and it's the same exposure times no matter what. It simply makes life easier. And you can make screens at night ;) Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
Thank you. I use an exposure unit, but always wondered what the variables would be if I used the sun since I live in the desert. Our town's motto is even "Where the sun spends the winter." But I think I'll stick to the exposure unit for consistency, thanks to this vid.
Maybe though the goal always isn't a "perfect" exposure? Thinking in terms of conceptual screen printing I see using the sun to expose a screen as a nice process of capturing a certain time/place/energy and the results are what they are. .... just a different perspective :)
For hobbyist and fine art stuff that is true and fine. But commercially, which is what I really teach, the sun is inconstant at best. Although here in Phoenix many sign makers use the sun with big vacuum tables outdoors and do fine. But we have a lot of consistent sun here and few clouds. And screens do not really capture time and energy like a piece of photographic film or paper. Emulsion is high contrast so it will either work or not. There are no shades of gray to be had in this exposure ;) The artsy part comes in designing the art and making the print. You will probably enjoy the next video though. I will use found objects to make a screen with my exposure unit and you could certainly do that in the sun too. Please stay tuned for that one. Thanks for watching. Screen Printing Equipment & Supplies - catspitscreenprintsupply.com/
You're very welcome. I try to do my best but everyone has their own methodology. While the sun can be used, it's more difficult than using an exposure unit. I'm glad you enjoy my video work! Thanks for watching. Screen Printing Equipment & Supplies - catspitscreenprintsupply.com/
Not sure if you ever exposed a screen in the sun based on some of the information you provided. Although I am not advocating using the sun, it is possible to burn screens in 1:45 to 2:00 minutes not hours. Some of the 2 minutes screens gave me an 8 on the exposure strip. Now if it is cloudy and raining you might have a problem. The other variables you discussed also apply to the 500 watt light source as well, and now your talking 22 to 25 minutes using a dual cure which is what I used above.
Dual cures will have a huge exposure latitude so maybe these were severely under exposed. This is from the description for that emulsion: General recommendations. 500 Watt Halogen, 12-13 minutes. Unfiltered UV Black light. 4-5 Minutes. Metal Halide: 250-280 Light Units. So for you to have done it in 1 - 2 minutes is amazing. The sun should have taken you about 20 minutes. Halftones are very difficult to get off in the sun and a point source like a work lamp will definitely work better. ☠
ive been having issue with speedball emulsion , im exposing with the 500 watts light, and when its time to wash out, i can i see my graphic but the emulsion doesnt go away. should i reduce my exposing time ?
Probably. If you can see the latent image but it will not washout, your film may not be dense enough. That would require an under exposure to compensate for. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
It’s probably the sandwich you’re getting with the film positive or the film positive itself. It’s hard to say without more information. If you have very fine lines you may need a higher mesh count. Make sure to “black out” whatever side of the screen you face away from the exposure light. Thanks for watching and leaving a comment! ☠
Yeah it would be interesting for everyone around the world to chime in here and let us know how well it works for you. Elevation is another factor I didn’t mention specifically but it goes with region. Thanks for watching and leaving a comment! ☠
So what is the point of a color safe bulb if it only response to high intensity UV light? Yeah, I know, light bulbs have UV light, red/yellow bulbs don't, but what I am saying, in my house we don't have white glowing bulbs, we have the yellowish/gold bulbs or could you just use a dimmer switch, hell, would you even have to, if you need a 500w UV bulb, a 60w regular bulb would do very little, not nothing, just very little. Correct?
There is a small amount of UV light in most light about the house. While it would take much longer to expose, we try to eliminate any variables by working with safe lights. But you will see many people do screen making in regular office type fluorescent lights. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
You’re welcome. If you have an exposure unit made for screenprinting I would recommend continuing to use that. Thanks for watching and leaving a comment! ☠
Thanks a lot for the great info! I'm planning to build a work light exposure rig like yours, I was wondering what would be the largest frame size it could handle. The largest ones that I plan to burn are 28x18 inches. Is that too big?
You should be able to expose screens as big as your exposure unit can handle. My unit can do up to 23x31 OD screens. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
I have a question i was reclaiming a screen I got it cleaned but there are small areas where emulsion still is is there anything I can do to get it all out I've used emulsion remover but it doesn't remove the spots any ideas on what can help
You’re very welcome. The sun is not easy to work with at all. The Dry Stencil system is a bit finicky so it takes some messing with. Also the right laser printer helps a lot. But RhinoTech will be able to help you more with that than I can. Thanks for watching and leaving a comment! ☠
Only the film positive sandwich and bounce are the same variables with the work lamp. But that is much easier to deal with. And depending on the emulsion most people I talk to who use a 500 watt work lamp are 10 minutes or less. My photopolymer takes 3 or 4 minutes that way. 30 seconds with an industrial black lamp. So each person's results vary depending on your particulars. And remember I never said it can't be done or isn't. I only suggest using a more stable light source. ☠
+Art Barnett That depends on the emulsion, film positives and the UV of the specific light you're using. It can vary a lot especially due to emulsions. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-BoBbN_gVsQk.html Thanks for watching. Screen Printing Equipment & Supplies - catspitscreenprintsupply.com/
+Claire Sophia You’re very welcome. Glad I can help out through my videos. Thanks for watching. Screen Printing Equipment & Supplies - catspitscreenprintsupply.com/
I am using an exposure unit like the stand you have. Its one that I made with a 500 watt light. I am using Saati Textil PV emulsion. My problem is getting the fine lines to clear out. I have tried putting weights on the screen but still get over exposure for little lines. Could it be the wood screens? Do you have any suggestions to get a better burn with a stand unit?
Hi Jonathan, thanks for the video about Sun exposure, I tried that a few weeks ago but it was under exposed. I also tried to use the Dry Stencil transfer technique but that too has not been working the way I'd hoped. Sent Graig a picture of my problem, (can't get the center to transfer correctly), have tried different settings and used the vinyl sheet as he suggested. Also tightened the pressure on the heat press, that too didn't work. If you have any ideas, please let me know? Thanks so much!..
Hi I have a question catspit am trying to buy a new manual press but I don't know wish one to buy am looking for a 8 colour 6 station Riley Hopkins look OK and vastex are to hi any advice thanks
Hello. I have no clue. I never tried to use anything like that. If has UV output then you may be able to use it. Thanks for watching and leaving a comment! www.catspitproductionsllc.com/ - catspitscreenprintsupply.com/
Yes I sure have. I have been screen printing since I was 11 from home. I’m 43 now. I have never seen a dual cure emulsion expose in 1 or 2 minutes in the sun. Not even in AZ. But maybe your elevation or region and emulsion have something to do with that. A 500 watt work lamp is not a better UV light source than the sun necessarily rather it is far more consistent and will allow you to use the same exposure times with the same emulsion and mesh. ☠
I think maybe but your exposure times will be very long. I would just buy the UV bulbs: catspitscreenprintsupply.com/small-tools-electrical-items/ Thanks for watching and leaving a comment! www.catspitproductionsllc.com/
thanks replying sooner. but you know sir, from where i am and for what i can afford, buying such things for me as a starter printer is costly enough. I'm always watching your vids for reference but since the tools, equipment and materials are based overseas, i can't make a out a quality print like the ones you produce.all i can do is dream on how can i acquire one of your kits. by the way, as an estimate sir, how long would it take to expose the screen on an ordinary florescent tube? thank you sir.
rainer gomez Sorry my friend I don’t know where everyone is and what they have at their disposal. I can only advise what I know. I do not know how long it would take to expose any given emulsion to a regular fluorescent bulb. I have never done that with any emulsion. When I was in High School my brother did it so I know it is possible but I do not recall exposure times or what emulsion we were using.
thank you so very much kind sir for your compassionate response. wish i could be your apprentice. i actually formulate a solution for exposing my screens from the sun. i ruined three of them for overexposing. the exact time sir would be 5 to 10 seconds.(12 to 3pm very sunny day.) my new problem is that i dont know if i can print a so called cmyk print on my water based inks. also i dont know if my 100 mesh screen could do it.
Sun worked perfectly for me. I don't know what I have been doing wrong but the LED light did not work at all. I bought the most powerful bulb of 1500 Lum and it was total FAIL even after 60 min of exposure, while the sun burned my screen perfectly within 5 minutes.
Okay so emulsion is only responsive to UV light. While the sun may have about 180 nano meters UV light at best, an LED light may or may not have high UV output. Ideally we want 300 to 400 nano meters UV light to expose emulsion easily. The LED and fluorescent lights we use for exposure units are actual UV lights. Not ordinary lights you might use for lighting a home. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
@@CatspitProductionsThanks for your response! little update. Indeed the most powerful home bulb didn't work, however, the 2000 lum. LED floodlight worked okay with 30 min of exposure. Plus, I live in Northern Ireland where a sunny day is something like a sensational event 😅 . At least the the technical light is controllable in comparison with the sun.
@@ArtemiosFilatov My pleasure to help out where I can. Okay so if an LED flood light is taking 30 minutes, that means it's very low UV output. Back in the 80's my brother used to use regular fluorescent office lights to make screens and that took 30 minutes plus.
Okay just to be clear, I am not being precise with exposure times here at all. They can vary greatly depending on many variables. I am exaggerating the figures here perhaps in order to make a point. Also I am not saying a 5oo watt work lamp has more UV light than the sun rather that the work lamp will be more consistent and you will be able to have easily repeatable results as opposed the sun. Come get some Catspit~! ☠
My advice is to buy a RANAR press from this company called Catspit Productions. Their customer service is very personal and they’re screen printers helping other screen printers... LOL ;) Thanks for watching and leaving a comment! ☠
Maybe your work lamp bulb was very old too. The older the bulb the longer the exposure time. Try a new bulb and about 18 inches sounds right to me but you could try lowering the light. ☠
I can't specifically say. That all depends on your variables such as where you are and what time of year it is and what emulsion you are using.... etc. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
I follow: ] hah always some how give me a giggle Mr.Roboto: ] must give you a special brownie when I travel to Arizona again, does Catspit have a business location m,any ways many thanks for all the shares, God Bless you: ]
My pleasure. Thanks ;) I’m working on it. The Cat grows wrestles. Thanks for watching and leaving a comment! www.catspitproductionsllc.com/ - catspitscreenprintsupply.com/
lol... the point is it's easier to use a consistent light source. Makes it the same every time. Besides, emulsion likes UV light in the 300 to 400 nm wavelength. The sun on it's best day is at about 180 nm UV or so. There are sign shops here in Phoenix who do use the sun for very large screens. However, they have a lot of experience in doing so. You can do it but if you want the same exposure time day or night, winter or summer, then an artificial light source is the easiest. The more UV the better. Thanks for watching! Screen Printing Equipment & Supplies - CatspitScreenPrintSupply.com/
