Hey thanks for the info! I was going to use regular glass but, now I know there is a difference between type of glass to use for an exposure box! thanks!
Use clear vacuum bags like those used to save storage space by squeezing quilts. Put inside screen, film positive, black cardboard and a thick cotton rope to help your vacuum cleaner to soak the air Inside the frame. Just like the professional vacuum exposure units. Best regards from Seville, Spain.
Can you give an example of an exposure time you've successfully used with that unit (with photopolymer emulsion)? And what is the distance from the surface of the light to the underside of the glass? Thanks.
Sorry for the late reply - with photopolymer emulsion I have narrowed my exposure time to 1 minute 25 seconds, and the distance between the light and glass is 12 inches.
@@joshisterrific I grabbed one of these UV LED lamps (the same one you're using here) and it's worked out great. For anyone needing another example, with single coat front and back with Ecotex AP Blue on 160 mesh, at 18" for 1 minute 40 seconds. Dialed it in with a Stouffer"s exposure guide. Consistent 7s for about six burns now.
It must be my lucky day... Thanks Josh. I'm new to the big screen printing poo and I love DIY. I bought your light, hope you got some $ from that affiliate link!!! I'm going to try a build for my 23x31 screen. Thanks man.
Hey! Great video, super helpful I ordered the light today :) How long do you expose your screens for and what is the distance between your light and the screens? Thank you
I'm exposing for 1 minute 25 seconds using photopolymer emulsion, and the distance between the light and glass is 12 inches. I would try using an exposure calculator to figure out your exposure time though, there are other variables at play here like the humidity level, how thick you coat the emulsion, etc.
I watch this video a couple of times. I built a florescent table. I think it’s time for the leds. The florescent tube when cold do not fire up properly. I have to start them several times before they fire. 8 tubes at $12.00 per tube is also A bit steep.
Hi, this is a really cool design! A video on how you made it would be really appreciate. Can i ask, Is there a reason why you put the light so deep in the box? How do you put pressure on the screen while you are burning it? Thank you
Hello, I put a little distance there so the light could spread across the whole surface of the glass. If I had a second light I would bring them in closer. But since I figured out my exposure time with that distance and it seemed to work fine I never felt the need to change it. If I were to do it again I'd make a shorter box with more lights and bring them in closer to the glass. For pressure I cut out a piece of foam board that fits the inside of the screen and I weigh it down with a couple of 5 lb weights. Seems to do the trick for me.
Add a timer! Let me know if you need help (which makes it even better), I built mine using a kitchen cabinet, the cost was $20 bucks for the cabinet and the glass was $15 from a local glass company, I made sure the glass had no UV blocking
Hey Josh: I created a very similar set-up, even purchasing the same light. I'm seeing just a hint of a burn after 10+ minutes. I'm thinking it could be the emulsion I'm using, which calls for a 500W light at 2 minutes. Can you recommend an emulsion that works well with this light?
Curious as to your thoughts, if i were to build a box that was bigger for larger screens, could using 2 of those 50w lights be helpful for a more even light distribution? Or would that just be overkill? Thanks for your video & your time!
Yeah I think that should work, otherwise you might not have enough light hitting parts of your graphic. A tip I've heard that I want to try on my next unit is to paint the inside of the box white, or line it with something reflective so the light bounces off the walls. It might even lower your exposure time.
@@joshisterrific Yeah i did the same for my own box of 29 x 24 inches using foil paper inside and the light bounces back to the graphic. Works perfectly.
Hi,, I just bought that Florescent Light and was wondering if you removed the Glass from the light fixture.. Does it matter if the Glass is in the fixture ??? Or should i remove it....
I've never used a light like that but if it produces UV light then it should expose a screen. However I would recommend the light I'm using, it's $50 on Amazon, link is in the description.
Yeah you could always switch them out. Only thing I'd maybe do differently with this one is not build it so tall. It's basically a square box, and I had to prop up the light inside so it was closer to the glass. I think this one is about 24" tall, so maybe something closer to 15" tall would work better?
Thanks! The box measures at 24" on each side. I can expose 18x20 screens easily, but 20x24 screens are a little trickier - the frames fit but the light doesn't cover the whole area evenly, so the next unit I build will be bigger with more light coverage.
@@nolamoe1386 I would add at least a couple inches on each side just to give it a little more room, so maybe 24x28? But honestly I would just make it as big as you can. You never know when you might need to make a screen bigger than 20x24. The more room the better!
The glass on my unit is about 12 inches above the light and my exposure time is 1 minute 40 seconds. This may vary with different emulsions, to get an accurate time you may want to use an exposure calculator. I used this free one from Anthem: www.anthemprintingsf.com/Screen-Exposure-Calculator-s/216.htm
No no no, don't use that lamp! Always use evenly distributed dimmable uv led strips (cost even less), otherwise you can't do very fine at work, let no one tell you otherwise.
Yes I have to make my own exposure unit and sometimes Rob God for His Sunshine exposure system without paying any electricity bills. Save plenty cash for a dinner party.
Am a newbie to screen printing plus I just got the same Quans UV LED light you're using off amazon, but the emulsion am using here in Nigeria isn't friendly enough, it just keeps giving a background, though the exposed design is crisp.
@@briefillneiss ah, yeah I think I'd go with a dual cure emulsion to start off, a little more forgiving and gives you a wider window to dial in the exposure time.
