wrote:
On Mon, 24 Jan 2011 04:34:07 -0800 (PST), wrote:

On Jan 23, 10:04 am, Fat Dumb & Happy "Fat Dumb &
wrote:
wrote:
I have a yard hydrant in my barn. It had heat tape on it, and the top
part above the ground was not frozen (I took off the head and put a
wire down). Its frozen under the ground. I know it's not to the
bottom, because its down at least 5 feet into the ground. Its frozen
below the surface. I have concrete around it, but there's a 1 inck
gap around the pipe, and I did have the heat tape down a few inches,
but I found that right below that tape the ground is frozen because I
tried to drive a piece of steel rebar into the soil.
I put a propane torch on the pipe right above the concrete level and
got water to boil out the top, but it's still not working and cant
lift the plunger. Is there some sort of electrical rod that I could
drive melt into the ground or anything made for that? I did dump some
boiling water around it too. I capped the top so I can use the rest
of the water on the property. and have an electric heater next to the
pipe, (heat tape is off now, so I could use torch). This hydrant is
in a small room, so that electric heater should heat the room but it's
not going to get what is underground. Anyone have any ideas what to
do?
Then, when I do get it unthawed, what can I do under the concrete
level to keep it thawed? They say not to put that heat tape
underground. I did have it down abiut 2 inches into the concrete, but
not more. I sure cant think of any other way to do it.
IDEAS NEEDED????
Thanks
Jake
If if if, the line isn't plastic, if ya can make a circuit with the
ice block in the circuit, if ya can get enough current to flow, if you
don't electrocute some cows and chickens,
this ought to work,http://weldingweb.com/showthread.php?t=8719
In this copy of The Procedure Handbook of Arc Welding (12th ed. 1973)
that I just bought there is a section on using an arc welder to thaw
frozen pipes. Now I can't imagine that this is a practice that Lincoln
would be wanting to promote today in these litigious times; in fact they
must be freaking out that there are still these old copies of the
handbook out there with a how-to on burning your house down with a
Lincoln HD Tombstone- Hide quoted text -

- Show quoted text -
There's just about zero risk of burning down the house, unless the
welder drops a lit cigarette. There isn't any arcing or welding going
on
. What is going on is the welder is used to pass current through
metal piping
to gradually heat it enough to melt the ice inside. One cable gets
securely clamped to each end of the pipe, where accessible. I've
seen it done on 50 -75ft runs of pipe. Takes an hour or two.

Just curious. I'm trying to picture this. You take a welder and
connect one cable to the metal hydrant pipe. That part is clear. But
you have to connect the other cable to the other end of the pipe.
Well, that end is under the ground. How the heck do you connect to
that end without digging it up? (Which digging would be impossible in
winter anyhow, without machinery, and if dug up, the hydrant may as
well be replaced). Most underground piping is plastic these days too,
so that eliminates connecting the welder to something like another
hydrant, which would likely be a hundred feet away (or more), and
think how long the welder cables would need to be. This just is not
making sense to me.

You connect it to metal somewhere else where the pipe surfaces.
Obviously this won't work if part of the path is plastic.


I also doubt any animals would get electrocuted. Welders only operate
at 24 volts or so. It's just lots of amps. I've gotten a tingle
several times when welding on wet ground if my shoes are wet. It dont
feel good, but wont kill anyone. The solution when that happened was
to just stand on a piece of dry plywood. Changing to dry shoes also
helps, but the plywood seemed to work best. (or both).


One infrequent hazard I have seen a warning for is if you are using an
electric welder to heat the water service pipe for a building - other
end a fire hydrant, with a metal municipal water supply. Since electric
services are connected to the water service pipe as a grounding
electrode, a possible parallel path is "grounding electrode conductor"
to service, to neutral through N-G bond, to another house through the
service neutrals, to that house's water service pipe through the
"grounding electrode conductor". You could have high currents in an
adjacent house that has rarely caused a fire. Temporarily removing the
system ground wire and water meter is probably a good idea (but could
rarely be hazardous in in itself).

--
bud--