Need to Register?

bloodandink · February 8th, 2008

I have an exposure unit with 4 florescent bulbs in it. They are Phillips 20 watt black light bulbs. My exposure time is about 8 minutes.

Lately one side of my screen is getting under exposed. I'm thinking it's the florescent tube on the left hand side. It looks fine and as bright as the others. But could it be just putting out less UV and so that's why the screen is under exposing?

Should i replace all the bulbs, so they are matched in age? Could i get 40 watt bulbs and cut my exposure time in half?

Thanks!

printandprint · February 19th, 2008

I'm not sure if the fluorescent tubes may be illuminating differently than each other, but I would presume that is a good possibility. As for the wattage, I don't think that luminosity scales 1:1 with wattage. I don't recall the ratio, but it seems like you need 4x the wattage in order to yield 2x the light output. You would have to check that your ballasts can handle that and that your circuit can handle that. It would need a heavy enough wire and the proper fusing.

RichardGreaves · February 20th, 2008

Lamps are cheap, time is expensive. I suggest you replace all the lamps at the same time.

40 watt lamps will always be more powerful than 20 watts, but still the bottom of the power range for screen making.

Need to Register?

Resources

T-Shirt Sites

Florescent Exposure Unit with one bad bulb?