Using welder to thaw our water line
sheph...@csi.com
to a garage I am building. Buried it down about 5 1/2 feet, but have
not gotten it fully covered (had hoped to run the electricity and gas at
about 2 1/2 and 2 feet respectively -didn't get done. Am going to try
to fill in the ditch and re-dig it in the spring - the dirt is pretty
frozen and it should be fun to fill in the ditch.
In any case, I am possibly exposed to a problem. Have a pretty good
AC/DC welder and quite a bit of cable. Should be able to reach both the
freeze-proof hydrant in the garage and the other end of the line in the
house.
What is the process of thawing the line? Amperage/Time/AC or DC/etc.
What damage can I do?
Thanks for the help
Randy Zimmerman
the run diameter, and material?? (copper or iron)
Possible damage can be from melted solder joints. Fires have been
started also. The welding machine has to have enough reserve (duty cycle)
to deliver a constant curent.
Randy
sheph...@csi.com wrote in message
<00000002090531....@csi.com>...
Jim Shepherd
is an older Craftsman 230 amp unit (buzz box). Have not welded at that
level, but have never had it trip out while welding some pretty heavy
stuff.
Jim
Randy Zimmerman <rzim...@sprint.ca> wrote in article
<aZMb4.32935$uj2.9...@newscontent-01.sprint.ca>...
Seppo Vaaja
it takes longer but is safer
the time will be several hours or more
check the pipe at the exposed ends for heat
especially where the pipe goes through wood
the pipe generally freezes close to the ends first near the surface
one trick is to thaw as soon as possible so less is frozen
it may "let go" and plug up a few times as well when the ice moves
if you use DC polarity does not matter
make sure the pipe is really well grounded (clean if necessary)
check the duty cycle on the machine as it will have to run for a lot longer
time than normal (although not as hot as usual) you will have to be at 100%
duty cycle
Jim Shepherd <sheph...@csi.com> wrote in message
news:01bf5557$5fdd0820$11e5afce@laptop...
Mike Graham
>Randy, the line is about 100 feet long and is 3/4 inch copper. The machine
>is an older Craftsman 230 amp unit (buzz box). Have not welded at that
>level, but have never had it trip out while welding some pretty heavy
>stuff.
The constant-current supply potential will probably be around 70 or 80
amps or so. Maybe it says in the manual? Or maybe there's a mark on the
dial indicating the point of 100% duty cycle?
--
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Mike Graham | Metalworker by trade
mikegraham at sprint dot ca | Rancher by choice
Caledon, Ontario, Canada | Weird by nature
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Randy Zimmerman
Current should be increased by 25 percent when using copper pipe.
With twice as many amperes the heating rate is four times as fast. if the
number of amperes is increased three times the heating rate is nine times as
fast.
When using DC the time and current required for thawing are about the
same for any length of pipe.
The table indicates 270 amps on 3/4 steel pipe takes approximately 3
to 4 minutes. Actual current and what the control dial will be different.
If you run 100 amps your cable should at least be a # 2 guage.
Usually those buzz boxes can run continuous at 70 amps. (There is a
circle on the dial number)
70 amps is a quater approx of 270 so it will take eight times as long.
That works out to up to 32 minutes. The copper needs extra hat so my guess
is that you won't see any chance of things melting until you have had it on
for half an hour.
There are ten points listed as precautions. Basically ensure good
electical connections , watch for over heating and hot spots, and don't
leave the site for anything!
Leave your water pressure on all during the process.
Jim Shepherd wrote in message <01bf5557$5fdd0820$11e5afce@laptop>...
>Randy, the line is about 100 feet long and is 3/4 inch copper. The machine
>is an older Craftsman 230 amp unit (buzz box). Have not welded at that
>level, but have never had it trip out while welding some pretty heavy
>stuff.
>