|While I was vacuuming the shop tonight, I noticed that sawdust was
|clinging to the hose and nozzle. When I touched the Shop Vac, I got
|quite a shock. There is obviously a seriously dangerous problem here,
|that could lead to sawdust explosions through static sparks, just like
|in dust collectors.
|So my question is how does one ground a shop vac hose? I have googled
|and, while there are many references to grounding PVC pipes and dust
|collectors, I have not seen anything about shop vacs. Have you done
|it? Or do you have any ideas on how to do it? I wouldn't want to be
|the victim of a Shop Vac explosion.
Fortunately, you can't ground an insulator. If you could, there
wouldn't be a piece of electronic on the planet that worked, thus we
wouldn't be having this conversation.
Why carge builds up is explained (more than you want to know) here:
Why an explosion is highly unlikely is here:
One of the problems is that _you_ become charged while vacuuming _if_
you are insulated from ground. Then you touch a grounded conductor
and zap. Most of us these days are walking around in insulated shoes.
In the electronics industry, where electrostatic discharge (ESD) is a
serious problem, they use heel straps that connect to bare skin and
the bottom of the shoe. They then walk around on conductive mats. We
don't have to go this far. Leather shoes and soles on concrete will
bleed off the charges that disturb us. Or just bend over occasionally
and touch the concrete with your hand. I can't speak to wood floors.
Raising the humidity will help, but that is usually counterproductive
to woodworking and in Arizona where I am 6 or 8% RH is not uncommon so
we have ESD problems in spades.
You can run a "grounding" conductor in or outside the hose and bring
the business end to the same potential as the vac or collector, but
you are *not* grounding the hose.
You can buy (semi)conductive hose. There are also topical treatments
that increase the moisture retaining properties of the surface of the