| Author |
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Roger Hamlett
Guest
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 Posted:
Sun Apr 03, 2005 1:10 am Post subject:
Re: Why Copper |
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"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:r2ft41phntiopjb57p796larhtq3igeeo8@4ax.com...
| Quote: | 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 |
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
| Quote: | 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.
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Best Wishes
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Boris Mohar
Guest
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| Posted:
Sun Apr 03, 2005 4:10 am Post subject:
Re: Why Copper |
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On Sat, 02 Apr 2005 19:49:21 GMT, "jim dorey" <skaar@ns.sympatico.ca> wrote:
| Quote: | On Sat, 2 Apr 2005 09:25:53 -0800, Watson A.Name - "Watt Sun, the Dark
Remover" <NOSPAM@dslextreme.com> wrote:
Brazing isn't soldering because it doesn't use solder.
i believe that even if it doesn't contain lead it can be called solder,
far as i know it refers to any non-fusion weld involving metal as a glue.
or are you refering to another reason it's not soldering?
|
Do not think that soldering is like gluing. Solder attaches itself to base
metal by dissolving some of it and forming an intermediate alloy layer. Ever
notice how unplanted copper soldering iron tip gets eaten away?
--
Boris Mohar |
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Tim Shoppa
Guest
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| Posted:
Sun Apr 03, 2005 4:10 am Post subject:
Re: Why Copper |
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Watt Sun wrote:
| Quote: | 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!
Tim.
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jim dorey
Guest
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| Posted:
Sun Apr 03, 2005 12:10 pm Post subject:
Re: Why Copper |
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On Sat, 2 Apr 2005 13:14:15 -0800, Watson A.Name - "Watt Sun, the Dark
Remover" <NOSPAM@dslextreme.com> wrote:
| Quote: | http://www.google.com/search?hl=en&lr=&oi=defmore&q=define:brazing
Looks like the consensus is that brazing is higher temp than soldering.
|
i do believe i mentioned something about higher temperatures.
--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/ |
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mike
Guest
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| Posted:
Sun Apr 03, 2005 6:10 pm Post subject:
Re: Why Copper |
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Watson A.Name - \"Watt Sun, the Dark Remover\" wrote:
| Quote: | "mc" <mc_no_spam@uga.edu> wrote in message
news:424aca3c$1@mustang.speedfactory.net...
Well... Gold and silver might be a bit better, but too expensive. You
will
occasionally see copper with gold, silver, or tin plating on it. Tin
enhances solderability but by itself melts at too low a temperature.
Aluminum is a good conductor but not solderable.
Change that to solderable with difficulty. There are fluxes such as
fluoride fluxes that will make soldering to aluminum easy. I soldered a
piece of aluminum by sanding it and covering it with a layer of greasy
flux to prevent it from oxidizing. Then with a soldering iron that puts
out a lot of heat, the solder wets the aluminum like other metals.
More importantly, aluminum
forms an *invisible* nonconductive coating as it oxidizes in air.
If that were true, you could not test for conductivity with a DMM for
example. The layer is so thin that it poses little barrier to
electricity. As far as invisible, well, if the aluminum has been
exposed to air then it is a given that it has the oxide layer.
|
I beg to differ.
The oxide presents a VERY BIG barrier to electricity.
You can test for conductivity because the oxide is thin and
your probe is pointy to puncture the oxide.
mike
--
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Watson A.Name - \"Watt Su
Guest
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| Posted:
Sun Apr 03, 2005 9:10 pm Post subject:
Re: Why Copper |
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"Tim Shoppa" <shoppa@trailing-edge.com> wrote in message
news:1112492924.190164.212510@z14g2000cwz.googlegroups.com...
| Quote: | 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!
|
Ooh, that sounds like fun! Bring the hot dogs, it's a weenie roast!
:o)
> Tim. |
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Michael A. Terrell
Guest
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| Posted:
Tue Apr 05, 2005 6:10 am Post subject:
Re: Why Copper |
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"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:
| Quote: |
Ooh, that sounds like fun! Bring the hot dogs, it's a weenie roast!
:o)
|
I'd rather roast a few trolls and assorted spammers, thank you!
--
Former professional electron wrangler.
Michael A. Terrell
Central Florida |
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David Lesher
Guest
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| Posted:
Thu Apr 14, 2005 1:35 pm Post subject:
Re: Why Copper |
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"Tim Shoppa" <shoppa@trailing-edge.com> writes:
| Quote: | 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...
--
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 |
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Watson A.Name - \"Watt Su
Guest
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| Posted:
Fri Apr 15, 2005 9:10 am Post subject:
Re: Why Copper |
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"David Lesher" <wb8foz@panix.com> wrote in message
news:d3lrje$eqv$1@reader1.panix.com...
| Quote: | "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...
|
That's sometimes why the firemen just let those scrap metal yard fires
burn themselves out. More water can make more fire.
> -- |
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John Woodgate
Guest
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| Posted:
Fri Apr 15, 2005 9:10 pm Post subject:
Re: Why Copper |
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Dave Platt <dplatt@radagast.org> wrote (in
<11602flm10ar061@corp.supernews.com>) about 'Why Copper', on Fri, 15 Apr
2005:
| Quote: | 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.
--
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 |
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Dave Platt
Guest
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| Posted:
Fri Apr 15, 2005 9:10 pm Post subject:
Re: Why Copper |
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In article <HX3lddqweBYCFwiE@jmwa.demon.co.uk>,
John Woodgate <jmw@jmwa.demon.co.uk> wrote:
| Quote: | 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...
--
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! |
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John Woodgate
Guest
|
| Posted:
Fri Apr 15, 2005 9:10 pm Post subject:
Re: Why Copper |
|
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Dave Platt <dplatt@radagast.org> wrote (in
<116096p5k5pcr93@corp.supernews.com>) about 'Why Copper', on Fri, 15 Apr
2005:
| Quote: | 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...
|
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 |
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Dave Platt
Guest
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| Posted:
Fri Apr 15, 2005 9:10 pm Post subject:
Re: Why Copper |
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In article <115up848eali2db@corp.supernews.com>,
Watson A.Name - \"Watt Sun, the Dark Remover\" <alondra101@hotmail.com> wrote:
| Quote: | 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.
|
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! |
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David Lesher
Guest
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| Posted:
Sat Apr 16, 2005 10:37 pm Post subject:
Re: Why Copper |
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dplatt@radagast.org (Dave Platt) writes:
| Quote: | 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...
--
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 |
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Fred Abse
Guest
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| Posted:
Sun Apr 17, 2005 9:10 pm Post subject:
Re: Why Copper |
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On Sat, 16 Apr 2005 22:37:37 +0000, David Lesher wrote:
| Quote: | 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...
|
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) |
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