Why Copper

"Tim Shoppa" <shoppa@trailing-edge.com> writes:

Watt Sun wrote:

So the guy had a firebrick mold
that he clamped around the two
conductors. He filled it with a
thermite compound that had a lot of
copper in it.

A common brand of this (so common that it's like "xerox" in use) is
Cadweld. The company I work for buys them by the tens of thousands.
Driving around in a truck or work train filled with thermite has known
hazards... hard to put out a fire that doesn't need any oxygen to burn,
and which happens to be melting its way through the truck bed/railcar!
Click to expand...

You can see rails being welded at
<http://www.aarc.com.au/aarc/news/photolib/photos_thermit.html>
That's a lot larger than the average CadWeld, but the same idea.

And about all you can do with thermite {or magnesium, for that
matter..} fires is pour sand on them until they run out of steam.
That's why first you are VERY sure there's nothing nearby that
burns...

--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
 
"David Lesher" <wb8foz@panix.com> wrote in message
news:d3lrje$eqv$1@reader1.panix.com...
"Tim Shoppa" <shoppa@trailing-edge.com> writes:

Watt Sun wrote:

So the guy had a firebrick mold
that he clamped around the two
conductors. He filled it with a
thermite compound that had a lot of
copper in it.

A common brand of this (so common that it's like "xerox" in use) is
Cadweld. The company I work for buys them by the tens of thousands.
Driving around in a truck or work train filled with thermite has
known
hazards... hard to put out a fire that doesn't need any oxygen to
burn,
and which happens to be melting its way through the truck
bed/railcar!


You can see rails being welded at
http://www.aarc.com.au/aarc/news/photolib/photos_thermit.html
That's a lot larger than the average CadWeld, but the same idea.

And about all you can do with thermite {or magnesium, for that
matter..} fires is pour sand on them until they run out of steam.
That's why first you are VERY sure there's nothing nearby that
burns...
Click to expand...
That's sometimes why the firemen just let those scrap metal yard fires
burn themselves out. More water can make more fire.

> --
 
In article <115up848eali2db@corp.supernews.com>,
Watson A.Name - \"Watt Sun, the Dark Remover\" <alondra101@hotmail.com> wrote:

You can see rails being welded at
http://www.aarc.com.au/aarc/news/photolib/photos_thermit.html
That's a lot larger than the average CadWeld, but the same idea.

And about all you can do with thermite {or magnesium, for that
matter..} fires is pour sand on them until they run out of steam.
That's why first you are VERY sure there's nothing nearby that
burns...

That's sometimes why the firemen just let those scrap metal yard fires
burn themselves out. More water can make more fire.
Click to expand...
Some years ago, a guy I know took some training in fire-extinguishing
protocols. One of the examples which came up in class was magnesium
fires. There are specialized extinguishers which can be used on
magnesium... they spray a finely divided powder which cakes on the
surface of the burning metal and forms a barrier layer which excludes
oxygen.

One of the sample questions in class was "What extinguishing protocol
do you use to put out an engine-compartment fire in an old VW Beetle?"

The correct answer was reported to be "None. The cost of refilling a
magnesium-blanketing extinguisher exceeds the value of the vehicle."

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
Dave Platt <dplatt@radagast.org> wrote (in
<11602flm10ar061@corp.supernews.com>) about 'Why Copper', on Fri, 15 Apr
2005:

The correct answer was reported to be "None. The cost of refilling a
magnesium-blanketing extinguisher exceeds the value of the vehicle."
Click to expand...
My answer would be 'water', because then there would be less trash to
clear away.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
In article <HX3lddqweBYCFwiE@jmwa.demon.co.uk>,
John Woodgate <jmw@jmwa.demon.co.uk> wrote:

The correct answer was reported to be "None. The cost of refilling a
magnesium-blanketing extinguisher exceeds the value of the vehicle."

My answer would be 'water', because then there would be less trash to
clear away.
Click to expand...
Yeah, but the personnel and asphalt damage from the live-steam
blowback might be prohibitive...

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
Dave Platt <dplatt@radagast.org> wrote (in
<116096p5k5pcr93@corp.supernews.com>) about 'Why Copper', on Fri, 15 Apr
2005:
In article <HX3lddqweBYCFwiE@jmwa.demon.co.uk>, John Woodgate
jmw@jmwa.demon.co.uk> wrote:

The correct answer was reported to be "None. The cost of refilling a
magnesium-blanketing extinguisher exceeds the value of the vehicle."

My answer would be 'water', because then there would be less trash to
clear away.

Yeah, but the personnel and asphalt damage from the live-steam blowback
might be prohibitive...
Click to expand...
Oh, you'd have to stand well back, but it's a very 'green' solution - an
example of the 'hydrogen economy'. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
dplatt@radagast.org (Dave Platt) writes:


Some years ago, a guy I know took some training in fire-extinguishing
protocols. One of the examples which came up in class was magnesium
fires. There are specialized extinguishers which can be used on
magnesium... they spray a finely divided powder which cakes on the
surface of the burning metal and forms a barrier layer which excludes
oxygen.
Click to expand...
Well, that's Class D, I think.

"Purple K" and "Ansul" powder are rated for Class D, but it takes
a large quantity to do the job; sand is cheaper...


--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
 
On Sat, 16 Apr 2005 22:37:37 +0000, David Lesher wrote:

dplatt@radagast.org (Dave Platt) writes:


Some years ago, a guy I know took some training in fire-extinguishing
protocols. One of the examples which came up in class was magnesium
fires. There are specialized extinguishers which can be used on
magnesium... they spray a finely divided powder which cakes on the
surface of the burning metal and forms a barrier layer which excludes
oxygen.

Well, that's Class D, I think.

"Purple K" and "Ansul" powder are rated for Class D, but it takes a large
quantity to do the job; sand is cheaper...
Click to expand...
Won't the magnesium take its oxygen from the sand (SiO2), and reduce it to
silicon? Similar to the thermite reaction? In that case, it would continue
to burn.

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
 
"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:r2ft41phntiopjb57p796larhtq3igeeo8@4ax.com...
On Sat, 02 Apr 2005 15:00:26 GMT, the renowned "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

jim dorey wrote:

and iron and steel are soldered all the time, in industry, in home
shops,
no big problem, but it's called brazing, cause brass is used as the
solder
i guess. the temps are quite high, so it's not really applicable to
electronics, but i suppose industrial cabling could use it.

Brazing is done with "hard" (silver) solder. It doesn't seem to have
anything to do directly with brass- the other meaning of "braze"
(decorate, make of, or make hard like brass) came from a different
word (OE "braes") according to AH4.
Actually, 'brazing', did originally use brass, and still does for many
Click to expand...
processes. However the term was first stretched to cover brass alloy rods,
that melted at lower temperatures than brass, and latter to include
'silver soldering'. Many of the so called 'silver solders', have very low
silver contents indeed, and some have none (palladium alloy solders for
example). In jewellery work, there are about five different 'grades' of
'silver solder', with the hottest (hard or 'enamel' grade - because the
melting point is high enough to allow enamelling), while the lowest
temperature versions have melting points only a little above the
conventional tin/lead solders.
The terms have 'spread', to the point where you have to be very careful.
Normally, the so called 'silver solders', used in industry, still have a
significant quantity of brass, so joints using these, are quite regularly
referred to as 'brazed', or 'low temperature brazed', and many people now
use 'brazing', generically to cover any form of hard soldering (including
things like aluminium soldering...). The dividing lines now, are normally
drawn at 450C, for 'soldering', 450 to 900C, for 'low temperature
brazing', and 900C+, for 'high temperature brazing'. Have a look at:
http://www.manufacturingtalk.com/news/cpp/cpp109.html

I ran into a problem where someone tried to fix a leak in t water
cooled TV transmitter by braising the brass fittings to the 2" copper
pipe. It was a real pain in the ass to salvage the brass fittings which
were long out of production. I had to cut the pipe off flush, then
carefully file away the braised areas before I could heat everything and
pry out the copper stubs. The brass parts were used to split the water
flow for different tubes and had been custom cast in the early '50s

BTW, "braising" is a cooking term- browning in fat, then simmering in
a bit of liquid. The root (OF "brese") is thought to be the same for
the two words.

Sounds like a real PITA to salvage the manifold. I imagine it would be
easy to have small leaks if you were not very careful.
Click to expand...
Best Wishes
 
Watt Sun wrote:

So the guy had a firebrick mold
that he clamped around the two
conductors. He filled it with a
thermite compound that had a lot of
copper in it.
Click to expand...
A common brand of this (so common that it's like "xerox" in use) is
Cadweld. The company I work for buys them by the tens of thousands.
Driving around in a truck or work train filled with thermite has known
hazards... hard to put out a fire that doesn't need any oxygen to burn,
and which happens to be melting its way through the truck bed/railcar!

Tim.
 
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