1951 Dash

Do you want it to glow, or be readable? The letering is/was actually a phosphoesscent paint that contained radium, a cancer causing pigment. You can get them to light up by removing the purple filters that are in front of each light bulb. You will need to clean them, but be careful as they are thin. Hold up each guage to a light bulb, then turn off the lights, if they glow, you are ahead of the game, as sunlight has not destroyed the paint.

If they do not glow, find and a good art supply store and buy a 1 lb bottle of glow in the dark pigment powder and a fine brush plus a fine brush. Plus a bottle of clear paint or ink. Mix the pigment into the clear base and carefully re- paint the numbers.

Leaving the ca outside will excite the dayglow pigment, but by re-installing the purple filter which act as a poor mands black light will mahe them glow again, even the clear bulb without the filter will help

Jeeze, Bill. There is NO radium in the pigment on Stude "blacklight instruments". The glow is caused entirely by the pigment (zinc salts, I think) fluorescing under the excitation of the long wave UV from the filtered dash lamps.

WWII vehicles, including my Weasel, DID have radium dials on their instruments. Radium dials will glow in the dark without any outside source of light, visible or otherwise, because the fluorescent pigment is excited by radiation from the radium. Curiously, the speedomter on my Weasel is printed with radium-bearing numbers only up to 30 MPH, and the remaining numbers (up to 60 MPH) are in regular paint. I guess they wanted to conserve that expensive radium paint, since the Weasel is only good for 30 MPH, anyway.

BTW, I have gone out and checked the Weasel's panel in the middle of the night, and, yes, you can see those radium numbers softly glowing. Enough for dark-adapted yes to read. Tick, tick, tick... :>)

I agree the fluorescent pigment degrades. In part, that may simply be due to a coat of dirt or oxide on the pigment that blocks UV from the lamps. Dust on the glass UV filters will also contribute to poor illumination of the gauges.

You can now buy LEDS that emit in the UV range. Seems to me that it would be worthwhile to try using them in a Stude blacklight panel, since they could be a much stronger UV source than a filtered incandescent bulb.

Gord Richmond

When I made the 50 Speedometer for the guy out west, everyone I contacted said that the lettering had radium. Since you cannot get it anymore I made a

195 mesh screen up and used white vinyl ink and added 1/2 lb of glow in the dark pigment, interestingly it turned the white ink the greenish white that looked like the real lettering. Using a white light it would excite tthe numbers for about a 45 seonds, but using the purple filters they always glow. I also did a few 56J radio dials with the Civil Defense logo. My Hawks radio has one in it.

Our PT-19 after 50 years had some dials you could partially read at night .......... in the hangar..............nobody in their right mind would fly that at night.