# Bulbs for Exposure Unit



## oasis2207 (Jan 17, 2009)

Hey guys i am planing on building my own exposure unit but am lost on what bulbs to get . Someone said that this bulbs should work Blacklight Fly Killer Tube T12 600mm 20W - Enviro-Lights can someone tell me if this will work for burning my screens . Or if anyone knows where to get the right bulbs in the uk could you please point me in the right direction .. Thank you !!!!


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## Wuhtzu (Apr 18, 2008)

Which emulsion do you use?

Personally I use the Ulano QTX, which is a ready to use direct emulsion and I expose (burn) my screens with a normal 500W halogen spot.

Ulano recommends black light (light in the UV spectrum) but normal visible light works just fine. 

All light sources emits a small amount of UV light but almost 100% of UV radiation is blocked by ordinary window glass (notice how you do not get tanned while you are behind glass - in your room or in your car). So either the emulsion does not need UV to cure or 500W of mixed light (UV, IR, visible ect.) has enough UV in it to cure the emulsion even though a high percentage of the UV is blocked by glass on the lamp AND the sheet of window glass I use to hold the transparent / stencils in place during exposure.

Personally I tend most towards the fact that the emulsion does not need UV, but just a certain amount of energy easily obtained via visible light. EDIT: Of course ultra violet light is has more energy per photon, so the exposure time will be different - presumably shorter.

I cure with a 500W lamp in 5 minutes.

Just some thoughts 

Regarding the bulbs you proposed your self - I'll guess they'll work just fine. EDIT2: Ulano, which is the emulsion manufacturer I happen to use, list exposure times for flourescent tubes 40W as around 300s (5min). So a few of those should do the job!


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## fragar (Jun 8, 2007)

I use QTX and blacklights and my exposure time is about 1 minute. The bulbs are 6 inches from the glass. The blacklights are 20 watts and 24 inches long. Make sure that you get the blacklights that are not filtered. I use 8 bulbs.


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## texasmoma (Jul 12, 2009)

i build mine with this same idea....under $20 all in all. thanks to this forum member.
you might want to try.

http://www.t-shirtforums.com/screen-printing/t58646.html


....under the screen (squeegee side) i use black 8inch thick foam.... top (shirt side) i press it with 5/8 thick clear glass (really heavy, it squeezes the film against the foam underneath very very tight. it's almost like having a vacuum type.)


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## oasis2207 (Jan 17, 2009)

Thank you for your replys guys ..


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## pss999 (Jul 18, 2009)

I'm just getting ready to try QTX also with my new exposure unit and was wondering if someone has a similar unit and is using QTX to give me a ballpark starting point (yes, I've read the Ulano tech docs, but there are a lot of variables to consider so it's really not clear where to start): My unit has 6 x 15w blacklight fluorescent bulbs. The tops of the bulbs are about 2" from the glass. I have 110 and 157 white mesh screens, coated once on each side with QTX. Any suggestions as to an exposure time would be greatly appreciated!

I also have some DLX so maybe if someone has opinions/experience with that I could try that too (or instead of the QTX). 

I do also have the Ulano exposure kit, but you still sort of need a starting point before you can refine with the exposure kits or strips...

Thanks,

Paul


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## pss999 (Jul 18, 2009)

Well, just to reply to my own post with the results of my tests, in case someone finds themselves with the same exposure unit and emulsion. I have the Logos 6-bulb (15 watt unfiltered blacklight bulbs) exposure unit, and with Ulano QTX coated 1/1 (sharp side of coater), after doing two step tests (along with Ulano gradient tests), I found an ideal time of 1:00 to 1:15. Yes, that short! The first test I guestimated at 2:00 to 4:00 (based on the coarse 110 screens and weak UV bulbs and Ulano's tech sheet guidelines), and already at 2:00 I could see details were blown out, so next step wedge I started at 30 seconds and went up in 15 second increments to 2:15, and sure enough 45 seconds was weak/washing emulsion, 1:00 was perfect, and 1:15 was already just starting to blow out the super fine line details. So I'll proceed with screen burning tonight at 1:10. So there you go.

Paul


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## JoeyR (Aug 28, 2009)

i just bought grow light bulbs? they are f15t8 bulbs not sure if they work.. do they?


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## selanac (Jan 8, 2007)

pss999 said:


> I'm just getting ready to try QTX also with my new exposure unit and was wondering if someone has a similar unit and is using QTX to give me a ballpark starting point (yes, I've read the Ulano tech docs, but there are a lot of variables to consider so it's really not clear where to start): My unit has 6 x 15w blacklight fluorescent bulbs. The tops of the bulbs are about 2" from the glass. I have 110 and 157 white mesh screens, coated once on each side with QTX. Any suggestions as to an exposure time would be greatly appreciated!
> 
> I also have some DLX so maybe if someone has opinions/experience with that I could try that too (or instead of the QTX).
> 
> ...


PSSS999, 

I know this is an old post, but do you still have this exposure unit from Logo's? 

I have a similar one. It has an On/Off switch on the side, and the body is black, along with 6 - 15 watt bulbs. It also has that big foam pad with a MDF laminated plywood on top. 

Logo's told me to try 8 minutes. Received a pinkish glow around the image edges. Tried 9, 10, and 11 all with the same results. 

The screen is a 156 mesh, and Performance Screen's S.E.X. emulsion. 1/1 coat. 

Any suggestions? Guess I should start with 2.50 minutes and see what that gets me. 

Logo's also said they have two exposure units, but their website only shows one.


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