UV Exposure Units

[Clint Chadwick]

I'm jumping into alt processes starting with cyanotypes. Living in Switzerland, we have precious few sunny days this time of year so I was looking at artificial UV sources and I found these devices being sold on eBay: http://cgi.ebay.com/UV-Exposure-Unit-Hot-Foil-Pad-Printing-PCB-etc-/300369180466?pt=LH_DefaultDomain_0&hash=item45ef65f732

Having no experience with alt processes it's hard for me to judge if this thing would be useful/sufficient. Anyone have something similar?

It even looks like one might be able to avoid needing a contact frame with this thing. What do you alt process experts think?

[John Bowen]

Very interesting

[Vlad Soare]

I don't know about that device, though it looks like it might work.
I use a facial tanning lamp like this one (http://www.amazon.co.uk/gp/product/B0000D8B1Z/), which was approximately 80 dollars new. It covers 8x10" with some room to spare (I think it might cover 11x14", though I cannot guarantee that). It works great with cyanotypes and vandyke prints, with exposure times of five to ten minutes.

[cjbroadbent]

Clint, I was on the same track as you - looking at circuit-printing uv boxes and such - but shied away because the uv strips appeared to close and too separate. I ended up doing it myself (http://picasaweb.google.com/lh/photo/kVSDuKuh9dYY2DfJdPZidA?feat=directlink) with aquarium strips (from Switzerland, Ralutec Radium 11W/78 G23).

[Clint Chadwick]

Clint, I was on the same track as you - looking at circuit-printing uv boxes and such - but shied away because the uv strips appeared to close and too separate. I ended up doing it myself (http://picasaweb.google.com/lh/photo/kVSDuKuh9dYY2DfJdPZidA?feat=directlink) with aquarium strips (from Switzerland, Ralutec Radium 11W/78 G23).

That unit you built looks great. Can you describe what kind of fixtures (sockets) you used and how did you wired it up? It looks like a PC case fan you are using for the exhaust. Is it an AC fan or do you have a transformer/rectifier in there somewhere?

The facial tanning lamp sounds like a good idea except I'm struggling with the similar problem at the eBay item with how I would position it with enough distance from the contact printer.

[Mark Woods]

I built one also, somewhat similar to cjbroadbent. I don't have a fan and I have more tubes. Mine had to handle 11x14.

[Vlad Soare]

I'm struggling with the similar problem at the eBay item with how I would position it with enough distance from the contact printer.
Clint, the tanning lamp stands upright on its own. The contact printing frame simply leans against the wall, approximately ten inches from the lamp, like in the attached picture. It works perfectly.
I set the timer, plug in the lamp, then exit the room and come back later, when it's finished. I don't like to stay there while the lamp is on, as I suspect the UV might be harmful to the eyes. Better safe than sorry.

[cjbroadbent]

T....Can you describe what kind of fixtures (sockets) you used and how did you wired it up? It looks like a PC case fan you are using for the exhaust. Is it an AC fan or do you have a transformer/rectifier in there somewhere?
....
The box sits flat and the exposure frame slides in the front gap. The gap is covered for safety by the black plastic flap. The tubes come with self-ballast fixtures and screw on to the box. Wiring runs out from each fixture -and from the pc fan - to a 'mammoth' joint and from there to the wall plug. Exposure time with POP or argyrotype is about 10 minutes with bullet-proof negatives.
This one (http://picasaweb.google.com/lh/photo/iFjZpariwSzuejETbd3g7w?feat=directlink) with 6500K Airam bulbs is cheap and inefficient but does the job in about 20 minutes.

[Brian Ellis]

With some plywood, bulbs, and under-the-counter light fixtures you could build a light box yourself for a lot less than what this costs and probably have a better unit. Even with my very minimal carpentry skills I built a box (actually not a fully enclosed box, all you want is a top and two sides) myself. I had an electrician do the wiring but most people could probably do that themselves too. I don't remember the total cost but it was less than $100 counting the electrician's charge and was much bigger than this unit, also better suited I think for at process printing.

[bvaughn4]

With some plywood, bulbs, and under-the-counter light fixtures you could build a light box yourself for a lot less than what this costs and probably have a better unit. Even with my very minimal carpentry skills I built a box (actually not a fully enclosed box, all you want is a top and two sides) myself. I had an electrician do the wiring but most people could probably do that themselves too. I don't remember the total cost but it was less than $100 counting the electrician's charge and was much bigger than this unit, also better suited I think for at process printing.

+1 for DIY. Just finished one myself. 8 BLB bulbs in fixtures available at home improvement stores. Approximately $150 for everything and able to cover 20x24.

[Clint Chadwick]

+1 for DIY. Just finished one myself. 8 BLB bulbs in fixtures available at home improvement stores. Approximately $150 for everything and able to cover 20x24.

Had I been back in the US, I would most definitely go for the DIY method. Head on down to Home Depot or Lowes and have all the parts for less than $100. An afternoon in the backyard and I'm all set.

Here in Switzerland, both the availability and cost of materials make this kind of thing cost prohibitive. While wood is easy enough to get, I'm betting the light fixtures and UV bulbs are going to run me over $140 if I can find them at all.

Additionally, I did some reading where people experimented with the distance between bulbs and found that is was nearly impossible to get banding. One printer was laying the prints on the bulbs and claimed no banding occurred. I guess since the bulbs give out light in 360 degrees, perhaps banding is not a real problem.

In any case, I ordered one of these contraptions from eBay and I'll report back on how it works out. If it doesn't, I can always start on the DIY method.

[Bob Farr]

Hi, Edwards Engineered Products, www.eepjon.com, has a lot of information about the uv units they build. Some of it may be useful, at one time I was able to download diy instructions for a uv unit from this web-site. Bob

[mdm]

I needed a uv light to make carbon prints. In the end I got a 300W Osram Ultra-Vitalux E27/ES lamp from a lamp specialist shop. It is very quick, my standard exposure is 6 or 7 minutes with 4% Ammonium Dichromate, which is not a lot more than the fancy plate burners people are using. It cost about $50USD with a ceramic fitting at inflated NZ prices. http://www.osram.com/osram_com/Professionals/DisplayOptic_Lighting/Products/Ultraviolet_Lamps/ULTRA-VITALUX/index.html I have never used it for anything bigger than A4 which it manages easily but I believe it would just about manage a 12x16 if you lifted the bulb slightly. Long pdf http://www.osram.com/_global/pdf/Professional/Display_Optic/Display_Optic_NEU/DO_Lighting_Program_2008-2009.pdf Appropriate screenshots attached below. It puts out uva and uvb and its output is equivalent to ~5 18W blacklight tubes. Blacklight tubes dont put out uvb, only uva.

Snake lights can also be used, one Sandy King tested for a student was giving 30minute exposures. I thing they are very inexpensive.