Re: [VAL] 12 v Thin-Lite fixtures

[John Sellers <jsellers@xxxxxxxxxxxxxxxxxxxx>]

Forrest,

I agree with everything Dr. J said and will add my own $0.02 worth.

The only obvious difference between warm white and cool white fluorescent tubes 
is the phosphor, so I'm darned if I know why warm whites should be harder to 
start.  But we switched to warm whites in our home kitchen years ago and I have 
observed this phenomenon for years.

Rapid start fluorescent tubes depend on the electric field near the ends of the 
tubes for initial ionization, and are intended to be mounted close to a grounded 
metal surface.  So first make sure that the fixture is grounded like it's 
supposed to be.  (Not usually a problem in an Airstream.)  Dr. J's suggestion of 
a few turns of fine wire wrapped around the tube and connected to ground works 
very well.  (I did that once in a "decorator" fluorescent fixture that wouldn't 
start reliably right out of the box.  It fixed the problem.)

Another factor I have noticed over the years is that starting problems are a 
function of humidity.  When the warm white tubes in our kitchen fixtures get 
old, they begin giving starting problems in humid weather.

I once heard somewhere that fluorescent tubes are coated with a thin layer of 
silicone compound to reduce this sensitivity to humidity.  You _might_ try 
wiping a wee bit of silicone grease--the VA List's all-purpose electrical 
problem solver--around the pins at the ends of the tubes.  (Come to think of it, 
I'll have to try that in our kitchen)

And last but not least, do make sure that the tubes are the right ones for the 
fixture.  It used to be simple, but nowadays it seems like there are a 
bewildering variety of fluorescent tubes out there.

Best regards,

John Sellers
WBCCI/VAC #1587
1960 Pacer
Dayton, Ohio