In article .com, larry
moe 'n curly wrote:

Lots of people who tap circuit boards with wooden dowels to find
intermittent problems or who carve dowels to use as screwdrivers for
adjustments on CRT monitors or TVs that are running. So far, I've used
only plastic or fiberglass rods for this, but dowels are a lot easier
to buy locally.

Cleaner, drier wood is good for insulating line voltages - well, maybe
not quite good enough for making products with wood as the main
insulation... I would not mass-produce products using wood to hold
bare wires with line voltage. That's something plastics and ceramics are
for!

I have found dowel rod from a hardware store to be a good insulator -
so far - although I would not bet my life that it will insulate me from
several KV or 10's of KV.

As for old lumber that was in a basement for the past how many months or
years? Sometimes a good insulator, sometimes not... Usually reads
megohms to open circuit if you touch ohmmeter probes to it, but your hand
has more contact area. Old lumber in the garage is worse if anything, let
alone lumber that has been stored outdoors...

As for brand-new lumber? I have seen a couple examples not do well with
a neon sign transformer. Some lumber is not as good an insulator as the
usual dowel rods.
The problem is high variability!

If should I ever have to work on a single live wire live with several
KV, I would not stand on wood, but on a plastic milk crate or a plastic
bucket. (Better still make a platform of a bunch tied together with nylon
or polypropylene or other "plastic" rope/twine, so if I have to make a
sudden maneuver to keep my footing I won't have to worry about getting my
hands away from the high voltage before stepping onto the ground!)

- Don Klipstein )