This is my recent build of a UV light box. I decided I did not need an enclosure, and made this as open as possible to allow heat dissipation without the need for a fan. I use this in a darkroom so there are no issues with stray UV from outside, and I always wear UV eye protection (less than $3 at any big box home store).
I suppose some would say an enclosure might provide better exposure power by reflecting more light downward, but in my case I feel that isn’t necessary- my exposures for cyanotype have been 3 minutes and nothing in this unit ever gets hot.
I used whatever wood scraps I had around. The basic frame is made of standard 1x4’s and a few narrow strips. I mounted each tombstone pair on its own length of 1x1 then positioned them to bring each bulb as close to each other as possible (without touching). This seems to provide even lighting, though I haven’t tested this thoroughly. I used whatever woods screws available, pre-drilling the holes.
The frame was built to accommodate a vintage contact printing frame which measures approx 13x16. The clearance from the bottom of the fluorescent tubes to the surface of the contact frame is about 1.5 inches.
I already owned the 8 GE F15T8/BL tubes from a past project, but I see they are still available online for about $6 each. The shunted tombstones from eBay cost around $20 including postage. The two ballasts I bought online for about $15 each, and their integrated wires were long enough that I needed no additional wire or wire nuts.
I used a terminal block to connect a power cord and use an external surge protector strip for a switch. I did not connect a ground- there doesn’t appear to be any reason for grounding or shielding anything as in the old days of using magnetic ballasts with starters. I get no sound and no flickering. I have not seen evidence that pre-warming the tubes before exposure provides any benefits.
Total weight is about 8.5 pounds. I currently am working on 5x7 or 6x9 cyanotypes, but I could easily do 8x10’s or add another ballast and a few more bulbs if I wanted to go a little larger.
I suppose some would say an enclosure might provide better exposure power by reflecting more light downward, but in my case I feel that isn’t necessary- my exposures for cyanotype have been 3 minutes and nothing in this unit ever gets hot.
I used whatever wood scraps I had around. The basic frame is made of standard 1x4’s and a few narrow strips. I mounted each tombstone pair on its own length of 1x1 then positioned them to bring each bulb as close to each other as possible (without touching). This seems to provide even lighting, though I haven’t tested this thoroughly. I used whatever woods screws available, pre-drilling the holes.
The frame was built to accommodate a vintage contact printing frame which measures approx 13x16. The clearance from the bottom of the fluorescent tubes to the surface of the contact frame is about 1.5 inches.
I already owned the 8 GE F15T8/BL tubes from a past project, but I see they are still available online for about $6 each. The shunted tombstones from eBay cost around $20 including postage. The two ballasts I bought online for about $15 each, and their integrated wires were long enough that I needed no additional wire or wire nuts.
I used a terminal block to connect a power cord and use an external surge protector strip for a switch. I did not connect a ground- there doesn’t appear to be any reason for grounding or shielding anything as in the old days of using magnetic ballasts with starters. I get no sound and no flickering. I have not seen evidence that pre-warming the tubes before exposure provides any benefits.
Total weight is about 8.5 pounds. I currently am working on 5x7 or 6x9 cyanotypes, but I could easily do 8x10’s or add another ballast and a few more bulbs if I wanted to go a little larger.