|
Posted by Will on November 2, 2007, 2:59 pm
Please log in for more thread options
Came across this exchange ("Ask the Mechanic") in a farmer-oriented
magazine:
Q: "..could not get the pipe to weld...pipe was rusty because it had been on
the ground...welder was checked...it was ok."
A:"When you said the pipe had been on the ground for several years, you
answered your own question....It's a problem fully understood by
professional welders...Since the pipe is round, it has the ability to pick
up the earth's magnetism, which makes it nearly impossible to weld--it's
this repel and attract thing. Square tubing cannot pick up this magnetism,
only something round, like pipe... The pipe you purchase needs to be on a
rack off the ground... To check the pipe before you buy it, use a hacksaw
blade... If it attracts the blade, take your business elsewhere."
Never ran into this explanation before, although I, too, have had trouble
welding round, rusty pipe.
Comments, anyone?
Will
|
|
Posted by SteveB on November 2, 2007, 3:23 pm
Please log in for more thread options
> Came across this exchange ("Ask the Mechanic") in a farmer-oriented
> magazine:
> Q: "..could not get the pipe to weld...pipe was rusty because it had been
> on the ground...welder was checked...it was ok."
> A:"When you said the pipe had been on the ground for several years, you
> answered your own question....It's a problem fully understood by
> professional welders...Since the pipe is round, it has the ability to pick
> up the earth's magnetism, which makes it nearly impossible to weld--it's
> this repel and attract thing. Square tubing cannot pick up this
> magnetism, only something round, like pipe... The pipe you purchase needs
> to be on a rack off the ground... To check the pipe before you buy it, use
> a hacksaw blade... If it attracts the blade, take your business
> elsewhere."
> Never ran into this explanation before, although I, too, have had trouble
> welding round, rusty pipe.
> Comments, anyone?
> Will
Wrapping one of the cables around the piece can help. If it's worse, change
the direction of the wrap or the direction of the length. Seen this done to
reduce arc blow.
Steve
|
|
Posted by Martin H. Eastburn on November 2, 2007, 9:10 pm
Please log in for more thread options USE AC to degauss.
A car bumper will be magnetized. A square tubing can as well. A pipe
and everything else must be aligned to the pole lines and if it moves
or switches - it tries to do it in that direction.
The lines in a square tube simply work lengthwise easier than in a circle.
They will work in a square. Look at a motor. The windings are nor circular
nor are the poles.
I think it is a traditional concept. In the North Slope large pipeline -
that one is laid out interesting. MIG or TIG that and you might have trouble.
If two pipes (on the ground or flying in the air on wood) will 'fix' to
the field that passes through them at a different rate. Likewise alloy
comes into play.
Rusty means oxides all over. Hard to get metal to weld to an oxide layer.
Look at hot rolled sheet or anything. The scale is oxide. Can't weld to it.
Clean off the rust and give it a try.
If there is a magnetic field, then degauss it with AC.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/
SteveB wrote:
>> Came across this exchange ("Ask the Mechanic") in a farmer-oriented
>> magazine:
>> Q: "..could not get the pipe to weld...pipe was rusty because it had been
>> on the ground...welder was checked...it was ok."
>> A:"When you said the pipe had been on the ground for several years, you
>> answered your own question....It's a problem fully understood by
>> professional welders...Since the pipe is round, it has the ability to pick
>> up the earth's magnetism, which makes it nearly impossible to weld--it's
>> this repel and attract thing. Square tubing cannot pick up this
>> magnetism, only something round, like pipe... The pipe you purchase needs
>> to be on a rack off the ground... To check the pipe before you buy it, use
>> a hacksaw blade... If it attracts the blade, take your business
>> elsewhere."
>> Never ran into this explanation before, although I, too, have had trouble
>> welding round, rusty pipe.
>> Comments, anyone?
>> Will
>
> Wrapping one of the cables around the piece can help. If it's worse, change
> the direction of the wrap or the direction of the length. Seen this done to
> reduce arc blow.
>
> Steve
>
>
----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----
|
|
Posted by Leo Lichtman on November 2, 2007, 5:43 pm
Please log in for more thread options
"Will" wrote, quoting from printed reply: (clip)Since the pipe is round, it
has the ability to pick
> up the earth's magnetism, which makes it nearly impossible to weld--it's
> this repel and attract thing. Square tubing cannot pick up this
> magnetism, only something round, like pipe... (clip)
^^^^^^^^^^^^^^^^^
Pure BS. The metal was probably thickly coated with rust. The round vs
square part is totally bogus. Also, the earth's magnetic field is far too
weak to have such an effect.
|
|
Posted by Don Young on November 2, 2007, 11:42 pm
Please log in for more thread options
> Came across this exchange ("Ask the Mechanic") in a farmer-oriented
> magazine:
> Q: "..could not get the pipe to weld...pipe was rusty because it had been
> on the ground...welder was checked...it was ok."
> A:"When you said the pipe had been on the ground for several years, you
> answered your own question....It's a problem fully understood by
> professional welders...Since the pipe is round, it has the ability to pick
> up the earth's magnetism, which makes it nearly impossible to weld--it's
> this repel and attract thing. Square tubing cannot pick up this
> magnetism, only something round, like pipe... The pipe you purchase needs
> to be on a rack off the ground... To check the pipe before you buy it, use
> a hacksaw blade... If it attracts the blade, take your business
> elsewhere."
> Never ran into this explanation before, although I, too, have had trouble
> welding round, rusty pipe.
> Comments, anyone?
> Will
>
I do not think the shape or ground have anything to do with it, but I have
noticed that several steel objects lying N-S without being moved over a very
long period sometimes seem to be slightly magnetized. One of my vises which
is oriented N-S seems slightly magnetized and I suspect that hammering on it
may contribute to the effect. I seem to recall from high-school physics that
hammering on a steel rod aligned with a magnetic field would tend to
magnetize it.
Don Young, USA
|
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
> magazine:
> Q: "..could not get the pipe to weld...pipe was rusty because it had been
> on the ground...welder was checked...it was ok."
> A:"When you said the pipe had been on the ground for several years, you
> answered your own question....It's a problem fully understood by
> professional welders...Since the pipe is round, it has the ability to pick
> up the earth's magnetism, which makes it nearly impossible to weld--it's
> this repel and attract thing. Square tubing cannot pick up this
> magnetism, only something round, like pipe... The pipe you purchase needs
> to be on a rack off the ground... To check the pipe before you buy it, use
> a hacksaw blade... If it attracts the blade, take your business
> elsewhere."
> Never ran into this explanation before, although I, too, have had trouble
> welding round, rusty pipe.
> Comments, anyone?
> Will