Aluminium or Chromoly frame?

On Mon, 14 Nov 2016 15:05:37 -0800 (PST), wrote:

On Sunday, November 13, 2016 at 3:46:32 AM UTC-8, John B Slocomb wrote:
On Sat, 12 Nov 2016 14:19:05 -0800 (PST), "
wrote:

On Saturday, November 12, 2016 at 12:12:02 AM UTC-6, Ken Pisichko wrote:
The bottom line is: Steel is reliable, heavy and easily reparable.

steel frames - easily reparable with a welder/brazing outfit.

No. Quality steel frames are made with very thin hardened steel tubes.
Being thin, they cannot just be welded by anyone. Brazing does not
really exist anymore since so few people use lugs or fillet brazing to
make frames. Its probably true you can easily fix a Chinese steel
frame anywhere by anybody. But not quality steel frames. I have a
Don Walker fillet brazed track frame with broken down and top tubes.
Walker said he would fix it for about $1000+. Another frame maker
said he would not even try due to the thinness of the tubes. The
distortion from heating the tubes would require reaming and
straightening the tubes afterwards. He could not guarantee the frame
would be safe afterwards.

That is not really correct. There are plenty of welders out there that
can weld thin wall bike tubes. Have a look at the professional
welder's sites. You won't find this type of guy down at the corner gas
station and he won't be cheap either but there are plenty of them out
there. There is even a video some where on the net of a professional
welder welding a bike frame.

As for super thin tubes. Columbus NL tubes have 0.8mm butts. that is
0.0315". I know plenty of aircraft welders who spend most days welding
0.032" stainless.

John. welders that can be careful enough to weld 32 thou tubing generally
don't build bicycle frames. That is an art that is worth a who lot
more than you'd make pinching bicycles together.

Actually it is not a very limited "art". When I was in the service,
and I assume today, every aircraft welder in the Air Force could do
it. When I was in Texas, Boeing had a big program to replace or repair
the thin stainless heating and pressurization ducting in B-52's (all
X-ray tested) and had no problem at all in hiring a whole bunch of
guys to sit there and weld the stuff, so it isn't at all uncommon.

How ever I would agree with you that probably the average bike frame
builder couldn't pass a code certification test for welding those thin
tubes :-)

On Tuesday, November 15, 2016 at 3:50:29 AM UTC-8, John B Slocomb wrote:
On Mon, 14 Nov 2016 15:05:37 -0800 (PST), wrote:

On Sunday, November 13, 2016 at 3:46:32 AM UTC-8, John B Slocomb wrote:
On Sat, 12 Nov 2016 14:19:05 -0800 (PST), "
wrote:

On Saturday, November 12, 2016 at 12:12:02 AM UTC-6, Ken Pisichko wrote:
The bottom line is: Steel is reliable, heavy and easily reparable.

steel frames - easily reparable with a welder/brazing outfit.

No. Quality steel frames are made with very thin hardened steel tubes.
Being thin, they cannot just be welded by anyone. Brazing does not
really exist anymore since so few people use lugs or fillet brazing to
make frames. Its probably true you can easily fix a Chinese steel
frame anywhere by anybody. But not quality steel frames. I have a
Don Walker fillet brazed track frame with broken down and top tubes.
Walker said he would fix it for about $1000+. Another frame maker
said he would not even try due to the thinness of the tubes. The
distortion from heating the tubes would require reaming and
straightening the tubes afterwards. He could not guarantee the frame
would be safe afterwards.

That is not really correct. There are plenty of welders out there that
can weld thin wall bike tubes. Have a look at the professional
welder's sites. You won't find this type of guy down at the corner gas
station and he won't be cheap either but there are plenty of them out
there. There is even a video some where on the net of a professional
welder welding a bike frame.

As for super thin tubes. Columbus NL tubes have 0.8mm butts. that is
0.0315". I know plenty of aircraft welders who spend most days welding
0.032" stainless.

John. welders that can be careful enough to weld 32 thou tubing generally
don't build bicycle frames. That is an art that is worth a who lot
more than you'd make pinching bicycles together.

Actually it is not a very limited "art". When I was in the service,
and I assume today, every aircraft welder in the Air Force could do
it. When I was in Texas, Boeing had a big program to replace or repair
the thin stainless heating and pressurization ducting in B-52's (all
X-ray tested) and had no problem at all in hiring a whole bunch of
guys to sit there and weld the stuff, so it isn't at all uncommon.

How ever I would agree with you that probably the average bike frame
builder couldn't pass a code certification test for welding those thin
tubes :-)

You don't think that welding heavy stainless heating duct is like arc welding 0.030 high temper steel do you? These are not at all even close to being equal. I can weld or braze and I wouldn't even try to arc weld EL tubing. You have to be EXTREMELY precise and very fast so as not to overheat any section which would break the temper and allow that area to fail. And as we all know, these failures always occur at the most inauspicious time.

On Tue, 15 Nov 2016 09:56:32 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 3:50:29 AM UTC-8, John B Slocomb wrote:
On Mon, 14 Nov 2016 15:05:37 -0800 (PST), wrote:

On Sunday, November 13, 2016 at 3:46:32 AM UTC-8, John B Slocomb wrote:
On Sat, 12 Nov 2016 14:19:05 -0800 (PST), "
wrote:

On Saturday, November 12, 2016 at 12:12:02 AM UTC-6, Ken Pisichko wrote:
The bottom line is: Steel is reliable, heavy and easily reparable.

steel frames - easily reparable with a welder/brazing outfit.

No. Quality steel frames are made with very thin hardened steel tubes.
Being thin, they cannot just be welded by anyone. Brazing does not
really exist anymore since so few people use lugs or fillet brazing to
make frames. Its probably true you can easily fix a Chinese steel
frame anywhere by anybody. But not quality steel frames. I have a
Don Walker fillet brazed track frame with broken down and top tubes.
Walker said he would fix it for about $1000+. Another frame maker
said he would not even try due to the thinness of the tubes. The
distortion from heating the tubes would require reaming and
straightening the tubes afterwards. He could not guarantee the frame
would be safe afterwards.

That is not really correct. There are plenty of welders out there that
can weld thin wall bike tubes. Have a look at the professional
welder's sites. You won't find this type of guy down at the corner gas
station and he won't be cheap either but there are plenty of them out
there. There is even a video some where on the net of a professional
welder welding a bike frame.

As for super thin tubes. Columbus NL tubes have 0.8mm butts. that is
0.0315". I know plenty of aircraft welders who spend most days welding
0.032" stainless.

John. welders that can be careful enough to weld 32 thou tubing generally
don't build bicycle frames. That is an art that is worth a who lot
more than you'd make pinching bicycles together.

Actually it is not a very limited "art". When I was in the service,
and I assume today, every aircraft welder in the Air Force could do
it. When I was in Texas, Boeing had a big program to replace or repair
the thin stainless heating and pressurization ducting in B-52's (all
X-ray tested) and had no problem at all in hiring a whole bunch of
guys to sit there and weld the stuff, so it isn't at all uncommon.

How ever I would agree with you that probably the average bike frame
builder couldn't pass a code certification test for welding those thin
tubes :-)

You don't think that welding heavy stainless heating duct is like arc
welding 0.030 high temper steel do you? These are not at all even
close to being equal. I can weld or braze and I wouldn't even try to
arc weld EL tubing. You have to be EXTREMELY precise and very fast so
as not to overheat any section which would break the temper and allow
that area to fail. And as we all know, these failures always occur at
the most inauspicious time.

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

On Sunday, November 13, 2016 at 7:24:33 PM UTC-5, AMuzi wrote:
On 11/13/2016 5:32 PM, jbeattie wrote:
On Sunday, November 13, 2016 at 12:42:37 PM UTC-8, Frank Krygowski wrote:
On 11/13/2016 11:17 AM, jbeattie wrote:
I was always amazed by TIG welders. I'd drop the hood and say, "where the f*** am I . . . someone turn on the lights."


I'm still amazed by really good welders, even though I've done a fair
amount of welding.

But regarding "... someone turn on the lights," you can now buy
inexpensive welding masks or helmets that are transparent, but
instantaneously darken when the arc turns on. They make things _much_
easier, IME.

Or you can be more coordinated striking the torch and lowering your visor or helmet. I confess to not being a good TIG welder . I mostly just playing with the TIG torches at the adult ed shop and welded scraps together. I was more serious about doing brazing repairs or bosses on my steel frames..

One day, I'll take the frame building class at UBI.http://www.bikeschool.com/classes/fr...ilding-classes Make myself a super cool Ti gravel bike -- with lumpy welds.


-- Jay Beattie.


Gaswelding exhaust pipes/ mufflers is a great way to
understand thin (rusted) steel. A light touch is necessary
for that sort of work. Bonus points for salt water slush
dripping on your head.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

right....I've watched this process....piece of cake.

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily.

And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper.

I think that Frank's input would be a bit more valuable than mine.

On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good,
fast arc welder you only destroy the temper at the spot of the weld
and the added material adds additional strength to that location with
a softer metal that does not crack or break easily.

You are headed in the right direction, but you haven't gotten there
yet. Welding of any sort results in the melting of the parent metal
which anneals the metal in the weld zone and decreasingly the further
away from the weld zone until you reach a point where the temperature
isn't high enough to effect the "temper".

Contrary to what you say, the actual weld bead is not composed of only
the metal added by the welding rod, but is a mixture of the parent
metal and the welding rod material. It is quite easy to produce a very
brittle weld bead by ignoring this fact. The most common may be using
a stainless rod to weld steel. The stainless filler can absorb
sufficient carbon from the steel to become extremely hard and brittle.


And this is absolutely nothing like arc welding stainless or other
metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the
temper and that is why on the higher quality steel frames they would
often use silver solder to braze tube and lug together to lessen the
possibility of overheating the tube and destroying the temper.

That is just wrong. At least if referring to silver soldering, or
silver brazing, as it is now referred to.

Heat treating steel is a matter of hardening the steel to its hardest
possible state and than reducing this hardness by re-heating to a
lower temperature to reduce the hardness.

Any high strength silver brazing that I have seen done requires
heating the parent metal to at least a dull red temperature which is
certainly sufficient to reduce it's hardness.

What I think you are talking about is the so called "air hardening"
steels that when heated to a certain temperature and cooled simply be
being exposed to ambient air temperature will harden to some extent.

I might mention that I was making and hardening knives when I was 15
years old and while I didn't understand why heating a knife to a
"cherry red" and quenching it in salt water hardened the blade and
than re-heating it to a yellowish color tempered it, but I certainly
knew how to do it. As for welding I was a certified oxy-acet aircraft
welder (steel and aluminum) when I was 20 years old and my last U.S.
government certification - TIG welding stainless, aluminum and
titanium was done just before I retired from the Air Force.

I think that Frank's input would be a bit more valuable than mine.

On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote:
On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good,
fast arc welder you only destroy the temper at the spot of the weld
and the added material adds additional strength to that location with
a softer metal that does not crack or break easily.

You are headed in the right direction, but you haven't gotten there
yet. Welding of any sort results in the melting of the parent metal
which anneals the metal in the weld zone and decreasingly the further
away from the weld zone until you reach a point where the temperature
isn't high enough to effect the "temper".

Contrary to what you say, the actual weld bead is not composed of only
the metal added by the welding rod, but is a mixture of the parent
metal and the welding rod material. It is quite easy to produce a very
brittle weld bead by ignoring this fact. The most common may be using
a stainless rod to weld steel. The stainless filler can absorb
sufficient carbon from the steel to become extremely hard and brittle.


And this is absolutely nothing like arc welding stainless or other
metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the
temper and that is why on the higher quality steel frames they would
often use silver solder to braze tube and lug together to lessen the
possibility of overheating the tube and destroying the temper.

That is just wrong. At least if referring to silver soldering, or
silver brazing, as it is now referred to.

Heat treating steel is a matter of hardening the steel to its hardest
possible state and than reducing this hardness by re-heating to a
lower temperature to reduce the hardness.

Any high strength silver brazing that I have seen done requires
heating the parent metal to at least a dull red temperature which is
certainly sufficient to reduce it's hardness.

What I think you are talking about is the so called "air hardening"
steels that when heated to a certain temperature and cooled simply be
being exposed to ambient air temperature will harden to some extent.

I might mention that I was making and hardening knives when I was 15
years old and while I didn't understand why heating a knife to a
"cherry red" and quenching it in salt water hardened the blade and
than re-heating it to a yellowish color tempered it, but I certainly
knew how to do it. As for welding I was a certified oxy-acet aircraft
welder (steel and aluminum) when I was 20 years old and my last U.S.
government certification - TIG welding stainless, aluminum and
titanium was done just before I retired from the Air Force.

I think that Frank's input would be a bit more valuable than mine.

Uh, yeah, how was I able to silver solder without heating a steel to cherry red? When soldering something like a lug and the silver extrudes from the other side of the lug there has been sufficient temperature and the metal does not have to glow.

Today I can still silver solder electronic circuits using various tools since the very fine wires often require a good conductor at connection points without overheating the IC's.

On Thu, 17 Nov 2016 08:20:36 -0800 (PST), wrote:

On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote:
On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good,
fast arc welder you only destroy the temper at the spot of the weld
and the added material adds additional strength to that location with
a softer metal that does not crack or break easily.

You are headed in the right direction, but you haven't gotten there
yet. Welding of any sort results in the melting of the parent metal
which anneals the metal in the weld zone and decreasingly the further
away from the weld zone until you reach a point where the temperature
isn't high enough to effect the "temper".

Contrary to what you say, the actual weld bead is not composed of only
the metal added by the welding rod, but is a mixture of the parent
metal and the welding rod material. It is quite easy to produce a very
brittle weld bead by ignoring this fact. The most common may be using
a stainless rod to weld steel. The stainless filler can absorb
sufficient carbon from the steel to become extremely hard and brittle.


And this is absolutely nothing like arc welding stainless or other
metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the
temper and that is why on the higher quality steel frames they would
often use silver solder to braze tube and lug together to lessen the
possibility of overheating the tube and destroying the temper.

That is just wrong. At least if referring to silver soldering, or
silver brazing, as it is now referred to.

Heat treating steel is a matter of hardening the steel to its hardest
possible state and than reducing this hardness by re-heating to a
lower temperature to reduce the hardness.

Any high strength silver brazing that I have seen done requires
heating the parent metal to at least a dull red temperature which is
certainly sufficient to reduce it's hardness.

What I think you are talking about is the so called "air hardening"
steels that when heated to a certain temperature and cooled simply be
being exposed to ambient air temperature will harden to some extent.

I might mention that I was making and hardening knives when I was 15
years old and while I didn't understand why heating a knife to a
"cherry red" and quenching it in salt water hardened the blade and
than re-heating it to a yellowish color tempered it, but I certainly
knew how to do it. As for welding I was a certified oxy-acet aircraft
welder (steel and aluminum) when I was 20 years old and my last U.S.
government certification - TIG welding stainless, aluminum and
titanium was done just before I retired from the Air Force.

I think that Frank's input would be a bit more valuable than mine.

Uh, yeah, how was I able to silver solder without heating a steel to
cherry red? When soldering something like a lug and the silver
extrudes from the other side of the lug there has been sufficient
temperature and the metal does not have to glow.

Exactly. But I believe that the previous discussion used the word
"weld" a totally different proposition.

By the way, did you know that a very well made silver soldered joint
has a tensile strength of about 100,000 pounds? My question vis-a-vis
bike frames was always "why do you want to weld them?"



Today I can still silver solder electronic circuits using various tools since the very fine wires often require a good conductor at connection points without overheating the IC's.

On Thursday, November 17, 2016 at 4:34:17 PM UTC-8, John B Slocomb wrote:
On Thu, 17 Nov 2016 08:20:36 -0800 (PST), wrote:

On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote:
On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good,
fast arc welder you only destroy the temper at the spot of the weld
and the added material adds additional strength to that location with
a softer metal that does not crack or break easily.

You are headed in the right direction, but you haven't gotten there
yet. Welding of any sort results in the melting of the parent metal
which anneals the metal in the weld zone and decreasingly the further
away from the weld zone until you reach a point where the temperature
isn't high enough to effect the "temper".

Contrary to what you say, the actual weld bead is not composed of only
the metal added by the welding rod, but is a mixture of the parent
metal and the welding rod material. It is quite easy to produce a very
brittle weld bead by ignoring this fact. The most common may be using
a stainless rod to weld steel. The stainless filler can absorb
sufficient carbon from the steel to become extremely hard and brittle.


And this is absolutely nothing like arc welding stainless or other
metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the
temper and that is why on the higher quality steel frames they would
often use silver solder to braze tube and lug together to lessen the
possibility of overheating the tube and destroying the temper.

That is just wrong. At least if referring to silver soldering, or
silver brazing, as it is now referred to.

Heat treating steel is a matter of hardening the steel to its hardest
possible state and than reducing this hardness by re-heating to a
lower temperature to reduce the hardness.

Any high strength silver brazing that I have seen done requires
heating the parent metal to at least a dull red temperature which is
certainly sufficient to reduce it's hardness.

What I think you are talking about is the so called "air hardening"
steels that when heated to a certain temperature and cooled simply be
being exposed to ambient air temperature will harden to some extent.

I might mention that I was making and hardening knives when I was 15
years old and while I didn't understand why heating a knife to a
"cherry red" and quenching it in salt water hardened the blade and
than re-heating it to a yellowish color tempered it, but I certainly
knew how to do it. As for welding I was a certified oxy-acet aircraft
welder (steel and aluminum) when I was 20 years old and my last U.S.
government certification - TIG welding stainless, aluminum and
titanium was done just before I retired from the Air Force.

I think that Frank's input would be a bit more valuable than mine.

Uh, yeah, how was I able to silver solder without heating a steel to
cherry red? When soldering something like a lug and the silver
extrudes from the other side of the lug there has been sufficient
temperature and the metal does not have to glow.

Exactly. But I believe that the previous discussion used the word
"weld" a totally different proposition.

By the way, did you know that a very well made silver soldered joint
has a tensile strength of about 100,000 pounds? My question vis-a-vis
bike frames was always "why do you want to weld them?"



Today I can still silver solder electronic circuits using various tools since the very fine wires often require a good conductor at connection points without overheating the IC's.

I suppose I'm stuck with answering that they do weld these EL frames which would make me nervous. They don't use lugs on them because they are trying to build the lightest steel frames possible. But they also build EL frames with brazed joints. I don't know what the weight differential would be though.

But somewhere I read a comment that a man's EL bike fully built was 16 lbs which is the present UCI weight limit.

I sent a letter to the UCI asking them not to change the limit but received a reply that was sort of non-responsive and suggested that they had every intention of removing all weight limits.

On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote:
On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote:

On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote:

Given that the ducting was manufactured from 0.032" stainless I would
have to say that it is exactly the same. Given that "welding" is a
process whereby metals are melted and then fused together, with or
without additional filler metal, welding the same sort of material
using TIG is exactly the same process whether it is 4130 or stainless.
If steel, then once the metal is melted than any "temper" is
destroyed. In fact it is destroyed long before the metal melts.

I'm being a bit pedantic here as welding aluminum, magnesium or
titanium can be a bit difference due to the way the metal reacts.

Quite to the contrary in my estimation - when you are a good,
fast arc welder you only destroy the temper at the spot of the weld
and the added material adds additional strength to that location with
a softer metal that does not crack or break easily.

You are headed in the right direction, but you haven't gotten there
yet. Welding of any sort results in the melting of the parent metal
which anneals the metal in the weld zone and decreasingly the further
away from the weld zone until you reach a point where the temperature
isn't high enough to effect the "temper".

Contrary to what you say, the actual weld bead is not composed of only
the metal added by the welding rod, but is a mixture of the parent
metal and the welding rod material. It is quite easy to produce a very
brittle weld bead by ignoring this fact. The most common may be using
a stainless rod to weld steel. The stainless filler can absorb
sufficient carbon from the steel to become extremely hard and brittle.


And this is absolutely nothing like arc welding stainless or other
metals that are not extreme examples of hardened steel.

Brazing properly done to the proper metals does not remove the
temper and that is why on the higher quality steel frames they would
often use silver solder to braze tube and lug together to lessen the
possibility of overheating the tube and destroying the temper.

That is just wrong. At least if referring to silver soldering, or
silver brazing, as it is now referred to.

Heat treating steel is a matter of hardening the steel to its hardest
possible state and than reducing this hardness by re-heating to a
lower temperature to reduce the hardness.

Any high strength silver brazing that I have seen done requires
heating the parent metal to at least a dull red temperature which is
certainly sufficient to reduce it's hardness.

What I think you are talking about is the so called "air hardening"
steels that when heated to a certain temperature and cooled simply be
being exposed to ambient air temperature will harden to some extent.

I might mention that I was making and hardening knives when I was 15
years old and while I didn't understand why heating a knife to a
"cherry red" and quenching it in salt water hardened the blade and
than re-heating it to a yellowish color tempered it, but I certainly
knew how to do it. As for welding I was a certified oxy-acet aircraft
welder (steel and aluminum) when I was 20 years old and my last U.S.
government certification - TIG welding stainless, aluminum and
titanium was done just before I retired from the Air Force.

Why salt water?