Mounting Black light in shadow box

[WallofFrame]

I've been lurking on this site for sometime and have enjoyed the information shared in this forum. I am relatively new to picture framing and have started a "hobby business" out of my garage. I have a 40"X54" chalk drawing to frame that when exposed to a black light shows a hidden image. I would like to frame this in a shadow box moulding and mount a black light within the frame itself. The issues I am having are; where to find a black light with a profile that will fit within the frame and will light up the entire drawing and how would you change the bulb if/when it burns out? Any comments and/or ideas are welcomed.

Thanks in advance,

WOF

 

[preservator]

Light sources inside of a frame present serious safety issues and any design
should be checked by someone fluent with lighting and electronics issues.
That fixture may be a source of heat, which can attack the paper of the
drawing, and the closer the light source is to the art, the more it will cause
changes in the paper. Staging the light outside the frame should be safer and
simpler to handle, in the long run.



Hugh

 

[Jim Miller]

I suggest using a deep shadowbox frame and conventional methods, except on the back. Instead of a normal mount board, hinge the artwork to a sheet of clear acrylic; 1/4" thickness should do nicely. Then provide an air gap of 1/2" or more behind it, and a final rear glazing of milky-white acrylic on the back. Also provide a generous air gap between the front glazing and the art.

Hang the frame in front of a light source, which would shine through the acrylic and illuminate the art. Using milky-white acrylic would diffuse the light somewhat, and reduce the bright-spot. I suggest using a couple of 48" fluorescent lamps placed at least 12" away from the back of the frame.



The air gaps front and back would slow the rate of temperature rise in the frame, when it is illuminated from behind. The front air gap would also lessen the possibility of the chalk image transfer to the glazing.

For front glazing, I suggest using Museum Optium Acrylic. Its optical coatings reduce static charge to levels lower than ordinary glass, and it has the best visual properties, too.

 

[CAframer]

Given that the objective is to illuminate the subject with black light I wonder if Jim's suggestion would have the desired effect. Maybe? Maybe not. Flourescent black lights are available but I don't know if backlighting thru two layers of acrylic would have the desired effect.

Other options include:

1. Because of heat considerations already mentioned, using battery powered black lights (probably need two or three because they are usually no longer than 6") in conjunction with a front opening shadowbox frame (maybe a slider with a sizeable rabbetless liner to conceal the lights. Problem here would be longevity of the batteries. Front opening design would permit battery/bulb changes.
2. Using an external black light source. There are many different types available. This would be the easiest option to execute but I have no idea if it would provide sufficiently uniform lighting of the subject, given the objective to illuminate the hidden design.

 

[Jim Miller]

Ooops. I'm sorry, I read it wrong. Black light is not quite the same as back light, is it??


Never mind the above.

A black light from the front would work, but UV-filtering glazing would kill the UV light and defeat the purpose.

 

[DBecker]

Plenty of UV CCFLs are available that are under 3mm in diameter.
They typically have a lifespan of 30k - 50k hours.
Given the size of the piece, you'll need several spaced around the frame.
Fashion reflectors out of foil to aim the light towards the center to even the lighting.
Use a momentary button to turn it on, this will discourage heat build-up.

 

[realhotglass]

_

Remember, black lights emit UVa light, so the periodic timer to view is a great idea.
Like you find on museum textile displays for temporary view lighting.

UVa is the main damage causing light wave, so limited exposure should be an aim if you want longevity for the pieces (art, paper, mats).
A timer would also have the effect of display the piece both without and with hidden image showing.

Staging the light outside the frame as Hugh suggested is an option, but don't use UV glass or acrylic,
because it will block the required shortwave light !
_

 

[WallofFrame]

Thanks to all for your feedback, you have brought up issues I had not considered. If you have a source for me to explore on the black lights small enough to fit within the shadow box, please let me know.

Thanks,

WOF

 

[realhotglass]

Check out coin / bank note (possibly postage stamp) collecting suppliers.
Black lights are often used to determine genuine banknotes etc.

I'm sure a Google search for - Uv light money note - would yield some results.
This site came up on page one . . .
http://www.starmgc.com/blcklt.html
Try some other search words too.

You might be able to consider a mains powered light set up, or multiple light setup,
but if it can be wired up so batteries can be changed external,
then this might be an alternative for ease of use / safety.

Periodic timer switch could lengthen life of tubes and batteries.