Sunday, November 14, 2010

World's Shoddiest UV Box

I'm going to get this out of the way now and apologize for the quality of the photos. I don't own a functioning digital camera anymore (I loved my D1H, I miss my D1H) so these were shot with a borrowed point-and-shoot shitbox and using it was an indescribably excruciating experience.

I can't vouch for the safety of this contraption. So far I've manged to not electrocute/set fire to myself or anything else but I'd still have to say - build at your own risk.

For the time being I'm limited to doing 8x10s as my largest prints so I didn't build an enormous UV Box. There's ample room to go to 11x14 if I ever get a larger printer for digital negs and theoretically I should be able to do 13x19; however, I haven't tested how even the light is near the edges of the box. Six CFL blacklights give me an exposure time of 10 minutes for Kallitypes.

Materials used:

1. A 56qt/53L Sterilite plastic storage tub (on sale at Target for about $4)

2. 6x Feit Electric 13W CFL Blacklight bulbs ($5 each from Home Depot)

3. 6x plastic lamp holders ($1.50 each from Lowes. I chose these because wiring the connections are recessed a little into the mount)

4. 12x #8-32 washers and nuts (the screws came with the lamp holders)

5. 6-8 ft of wire (I used some 14 gauge wire I had laying around my toolbox. Probably overkill because if my calculations are correct (I doubt it) this thing only draws about 0.7A and 14 gauge is rated to 17A. I'm not an electrician so if anyone wants to weigh in with wiring recommendations...go for it.)

6. An extension cord or lamp cord or anything with a plug end. (I had the end of a cord from an old microwave or something laying around. You can probably pick up a cheap lamp cord for a few dollars.)

7. Krylon Fusion satin white spray paint. (About $4 from Ace Hardware)

8. Electrical tape

9. Wire nuts

Total Cost: Somewhere around $50

How it's made:

Tools needed:
- A drill with assorted bits
- A screw driver
- A wrench, socket, or pliers to hold the nuts (god that sound terrible)
- Wire cutters/strippers

The plastic tub was originally clear. I searched for white plastic and black plastic or anything that wasn't clear but found nothing suitable. While they are out there, they were either the wrong size or didn't have a reasonably flat bottom. The solution was to spray paint the interior. Plastic is difficult to spray paint but the Krylon Fusion worked great. I washed the tub and let it dry before painting (they can be a bit greasy fresh from the store). No need to sand since the paint somehow bonds with the plastic. The finish doesn't appear to be in any danger of flaking off. I gave it two coats but it still glows through quite a bit.

After the paint dried I placed the lamp holders where I wanted them (no exact measurements, just eyeballed it) and marked where the screws would go through. I drilled the holes out just slightly smaller than the screws and I don't remember what size bit it was. Then I drilled a slightly larger hole on one of the ends of the tub for the wires to exit.

The next part was kind of tricky. Actually more of a pain in the ass that smelled bad and made a mess. The lamp holders are meant to be mounted to a standard electrical box and the wires are meant to be tucked away behind them. I wanted to keep all the wires inside the box so I ended up drilling holes in the plastic lamp holders for the wires to pass through. The plastic is pretty durable and took a lot of swearing to drill through. Also, the drill bit gets hot and starts to melt the plastic some and it smells like someone threw a load of plastic forks into a campfire (it wasn't me I swear, I'm a better camper than that). Five of the six lamp holders need two holes drilled. The last holder in the chain only needs a single hole. Just be careful that you don't apply too much pressure while drilling because it seems like these things would be really easy to crack.

Once the holes were drilled I cut lengths of wire to run between the lamp holders. Strip the ends of the wire and attach them to the proper poles on the holders. These holders have two screws for each the hot and neutral connections which is very convenient. The final length of wire is a bit longer to run through the box. Once of these days I'll get around to securing it into place.

After all the holders were wired I secured them to the plastic tub with the screws provided and fastened them on the outside with the washers and nuts. I was going to use some Locktite on them so the whole thing didn't fall apart, but so far they're holding their own.

The last thing to connect was my hacked bit of extension cord so I could plug this thing in. I used some wire nuts found in the bottom of my tool box that had accumulated from other electrical endeavors. I added some electrical tape because it seemed like a reasonable thing to do. After that, I installed the bulbs and nervously plugged it in. Much to my surprise, all the bulbs lit and I didn't die.

When I'm making an exposure I sit it on the floor over my contact frame and plug it in. Using a step-wedge I determined the proper exposure for Kallitype to be 10 minutes, which is much faster than I expected. Maybe in the future I'll add an inline switch so I don't have to keep trying to find the outlet in my bathroom darkroom.


  1. i love watermelon in the background!!! go melon!

  2. I was hoping someone would notice that.

  3. I was going to comment on the watermelon before I even noticed that someone else had done the same. Sorry to hear about the "point and shoot shitbox".

  4. My version has the lights outside of the box with the box used for storage.

    Seems to be many ways to solve that cheap light source problem.