Another UV Light Box (16x20)

**denverjims** · 27-Sep-2013, 06:35

I have been thinking about exploring salt printing for a while and finally have gotten off my duff to begin. One step is to build a UV Light Box. In researching the subject, I have found several good sources from which to steal (ahem, "borrow") ideas - including several here in DIY especially a recent one by jp498. Also, I got a lot of local help from fellow LF'ers Keith Pitman and Jeff Graves.

I finally settled on a 12 bulb T8 design which could accommodate a 16x20 printing frame - more than I think I will ever need but I've been burnt before by not building to an adequate size and having to re-do.

A couple of notes on things I did a little differently than most of the DIY units I saw:

1. I liked the idea of lining the box with reflective material to increase UV effectiveness but rather than use the insulative stuff I found a Nashua product called "Extreme Weather Foil Tape" which is a thick aluminum foil with super hot/cold resistant adhesive. Easy to apply and takes up little room.

2. Rather than buy light fixtures I bought the 'tombstone' light tube holders (Leviton 23351, 60 cents/piece) and I found a ballast which ran 4 lights (Fulham Work Horse WH5-120-L ballast $16.59/piece) requiring only 3 rather than 6 for my 12 bulb unit. The tombstones screwed right onto the board on one side and the ballasts on the other. Wiring was straight forward and I saved some $$.

3. I cut the main board with the lamps & ballasts about 1" smaller than the inside of the box frame and mounted it via L-brackets. This allows the air to be brought up from below evenly around the entire periphery of the light source. Better airflow has meant cooler operation. Mounting the axial fan (Grainger 4WT47) on the top center of the box seemed to work fine.

4. I used 2 switches: one for lights and one for fan. Figured I might want to continue to cool box after lights were out.

Well, after it was all done, I ended up with what you see below.

Front View, door closed