[TenTec] Electric safety

[Dr. Gerald N. Johnson]

On Thu, 2010-02-18 at 18:57 -0600, Pumbaa wrote:
> Thanks for the safety tips.  I am sure the ALS-1300 at 50V and a peak of 50 
> amps could melt a screwdriver or a gold ring. Would wearing latex exam 
> gloves offer any extra protection when working on a radio?

Not much. They are only a fraction of a mil thick and good insulators
stand a few hundred volts per mil so long as there's no sharp points
against the latex. Latex isn't that great and its terribly prone to
holes of all sizes from touching sharp points. There are many sharp
points in radios of all vintages. Since the exam gloves are not tested
to be water tight or air tight or for their insulating qualities any
trust might be misplaced. 10KV lineman's gloves are much thicker and
have been tested (regularly) in a water bath while filled with water to
detect any leakage holes. And then when before the lineman puts them on
he fills each rubber glove with air and rolls up the cuff to put some
pressure on the glove. If it holds air he wears the glove, if not he
looks for another. Latex might pass that test initially but latex is
fragile and in use isn't protected like the lineman's gloves with a
leather outer glove.

At one point a few years ago I did some color printing in the dark room
that required using a strong sodium hydroxide developing bath and latex
gloves. At once as I was agitating the print I noticed a very soapy
feeling, my glove had ruptured with nothing more aggressive than the
print paper. I got to the sink in a hurry. And finished with another
glove or bamboo tongs.

The pressure on the latex from a finger nail or the round outside of a
ring could be enough to make it fail.
> 
> Tom AG8K
> 
73, Jerry, K0CQ