Steel no longer real?

On Fri, 01 Jan 2016 02:14:44 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 01:30:14 +0100


How come nobody ever says steel is real anymore?

Because new aluminium welding machines made alloy the
material of choice.

But aluminum welding dates back to about 1944 for GTAW and even
earlier for oxy-acetylene welding.

True, but modern weldig machines make the process easy.

Aluminium has a weak fluid phase. Means: from 'too cold'
to 'evaporating' is a tiny step. Modern machines can dose the
welding current pulses much better than a human expert can do.

That isn't the problem with welding aluminum. The main problem is that
the stuff doesn't change color when it melts. It is sitting there
looking all gray and solid and all at once it falls on the floor :-)

Oops, you are right, I looked it up.
Al suddenly shifts from solid to fluid without optical warning.

So, light-weight alu frames can be made for cheap.

Cheap welding is just a matter of MIG welding as both gas and TIG
welding take roughly the same amount of time per inch of weld.
If the material is thick enough it can even be "stick welded", for
that matter.

The machines used for making bike-parts from Al alloy
are computer controlled MIG ones that work in two steps --
first drop some material to the welding point,
then do the real welding. The worker or robot arm only has
to 'point and shoot'. That's what I meant: with such equipment,
you don't need a skilled craftsman at the machine any more.

I'm not sure what you are saying. MiG welding is very like "stick" arc
welding. You start the arc and go.

But "automatic" welding isn't really new. I think I mentioned the guy
I worked with years ago now that spent a day, in a Detroit car factory
pushing a button to trigger an automatic welding machine that welded
the axle tubes into a differential housing, and pipe rolling mills ere
automatically welding pipe nearly that long ago. In the late 70's I
visited a spiral pipe factory in West Java that welded 40 ft joints of
pipe automatically.



[originally, steel frames were not welded but soldered
using brass fitting ... remember those?]

Remember? I own two with silver soldered joints and one which I have
never taken the time to look.

I did own a bike built like this long ago,
and in fact didn't appreciate enough.
I was more interested in motorbikes and cars then ...
shame on me.
--
cheers,

John B.

On Fri, 01 Jan 2016 03:24:07 +0100, "Jakob Krieger"
wrote:

- Phil W Lee / Wed, 30 Dec 2015 18:54:12 +0100


Expert human welding is at least as good - but training and retaining
experts is expensive, and machines can do it far cheaper, while having
only minimal human supervision. THAT is the reason it is now so
cheap.

Of course. And it is the reason why (not all, but some)
cheap frames are perfect in geometry. And why work can be
done by children (welcome back to 1800).


[originally, steel frames were not welded but soldered
using brass fitting ... remember those?]

Remember? I have one, and have only ever had one bike that wasn't
constructed that way!
Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

These bikes did cost a little more than today,
compared to average income level.


What annoys me is that machine-built frames which are
cheap but not bad in principle have such crappy components
that they go to the bin in a few months.

I bought a "mountain" bike in Singapore, probably 20 years ago.
Aluminum frame and, as you say, cheap fittings. I had it on the boat
for, probably, ten years or so and when I finally sold the boat the
bike was almost unrideable. Rather then just throw it away I started
stripping the unusable stuff off and finally ended up with only the
frame and was going to throw that away until I saw a very up-market
MTB in the marina with exactly the same frame :-)

I ended up making a solid fork for my frame and now have an aluminum
frame utility bike :-)

Recently, I 'saved a DIY-market crap bike from the bin
by adjusting everything and changing a few minor parts
for a friend. He isn't a sporty mile-eater, and the bike
will serve him for quite some time.
I'll never understand this trash culture.


And recently, I 'shot' a bike-frame at flea market.
A 1998 Gary Fisher Ziggurat.
Welded aluminium, but perfectly done in any detail.
And not really bargain-priced when new.

I hate to tell you but that looks exactly like the frame that I
salvaged from my Singapore bike :-) Which I purchased new for S$ 100,
about 60 US dollars in those days.

Since that day I know that you really have to spend
money on a good frame. You need 15 $ in your pocket,
otherwise it won't work.

See above: Trash culture. I just fit surplus parts I had
lying around, and it is already a good bike. I am a bit too
tall for the frame size, so I won't spend a lot to really
rebirth it. But it won't go to the bin, and it will get
some fresh air time by time (for tours, I prefer the bigger
one with disk brakes and good hubs and rims).


More recently, I saved another one from the bin. A steel
(welded) cheap 28". I'll build this up until spring, so that
I'll have a city thing that looks too boring to be stolen.
Hubs and crank bearing are junk. Frame is like new, no rust.
Trash culture, once again.


And I love to go to museums and look how old tech-stuff
was made. Sorry, when I see a 1930 racer, I want to try
and ride it ... may be today's carbon things get some
1/100th seconds advance in competition, but I hate how
some (most?) people tend to under-estimate heritage.

Some time ago, I was at a place at east Adria (Jadran).
The neighbor guy took us with his motor boat (nut-shell),
and it hat a motor on-board made in 1910. Except of
cables and spark-plugs everything was original ...
I hope he will keep it in honour.
If not, I'll feed him to the sharks.

You have no idea how much better a modern outboard motor is :-)



I love modern stuff, too. No problem.


jk
--
cheers,

John B.

On Fri, 01 Jan 2016 03:36:09 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 02:39:36 +0100


Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

But I'm not sure that is a concern as the strength of a brazed joint
is so very largely dependent on the clearance in the joint necessary
to allow the brazing metal to penetrate the joint.

Silver soldering is stiffer and more durable.

Of course, acurracy of the pieces used is a much more
decisive point.


It might also be of interest to know that many silver brazing fillers
contain Cadmium which lowers the melting point and improves fluidity,
but which also produce cadmium oxide fumes when heated above 608
degrees (F), or 320 (C). Cadmium fumes are considered poisonous and
while they have been in use for many years should be treated with
respect.

Same with red lead or zinc chromate paint.

Perfect anti-rust, but poisonous.

A bit different though. You can paint red-lead or zinc chromate with a
brush perfectly safely but all you have to do is melt cadmium silver
solder to release fumes.

Any unless you melt the silver solder it isn't any use, at all :-)

--
cheers,

John B.

On Fri, 01 Jan 2016 03:45:18 +0100, "Jakob Krieger"
wrote:

- AMuzi / Wed, 30 Dec 2015 20:17:39 +0100


No one's more committed to hand metal joining than I, but
there are many applications for which a robot can be clearly
superior in quality and consistency (not to mention 24x7
consistency). That's not to simplify as 'robots are better',
only to note that with proper engineering they can be, and
in many cases are. Anyone who has done the same pass setup
repeatedly for 8 hours will probably agree.

Agree.

Robots are better doing stupid work all day long
with high precision.

See http://www.youtube.com/embed/8_lfxPI5ObM?rel=0
--
cheers,

John B.

On Fri, 01 Jan 2016 20:27:36 +0000, Phil W Lee
wrote:

"Jakob Krieger" considered Fri, 01 Jan 2016
02:14:44 +0100 the perfect time to write:

- John B. / Thu, 31 Dec 2015 01:30:14 +0100


How come nobody ever says steel is real anymore?

Because new aluminium welding machines made alloy the
material of choice.

But aluminum welding dates back to about 1944 for GTAW and even
earlier for oxy-acetylene welding.

True, but modern weldig machines make the process easy.

Aluminium has a weak fluid phase. Means: from 'too cold'
to 'evaporating' is a tiny step. Modern machines can dose the
welding current pulses much better than a human expert can do.

That isn't the problem with welding aluminum. The main problem is that
the stuff doesn't change color when it melts. It is sitting there
looking all gray and solid and all at once it falls on the floor :-)

Oops, you are right, I looked it up.
Al suddenly shifts from solid to fluid without optical warning.

And it conducts heat away so readily that keeping the hot spot
localised is more difficult.


Not really, at least with electric welding. Welding aluminum with a
conventional arc welder is not radically different from welding steel.
In fact the most noticeable difference is that the rate of metal
deposit seems nearly twice as fast as with steel rod and initially it
seems "wrong" to "push" the rod fast enough.

So, light-weight alu frames can be made for cheap.

Cheap welding is just a matter of MIG welding as both gas and TIG
welding take roughly the same amount of time per inch of weld.
If the material is thick enough it can even be "stick welded", for
that matter.

The machines used for making bike-parts from Al alloy
are computer controlled MIG ones that work in two steps --
first drop some material to the welding point,
then do the real welding. The worker or robot arm only has
to 'point and shoot'. That's what I meant: with such equipment,
you don't need a skilled craftsman at the machine any more.

No, just one to set it up.
The earliest systems for doing that were mechanical, and only capable
of doing welds that were geometrically simple - straight lines and
fixed radius curves, for example, where the machine can be built to
just follow that path repeatedly at a set speed.
Now they are computer controlled and reprogrammable, they can follow
complex and compound curves, and even reach places that a human
operator couldn't, and don't need to be completely rebuilt if the
design changes.

[originally, steel frames were not welded but soldered
using brass fitting ... remember those?]

Remember? I own two with silver soldered joints and one which I have
never taken the time to look.

I did own a bike built like this long ago,
and in fact didn't appreciate enough.
I was more interested in motorbikes and cars then ...
shame on me.



jk
--
cheers,

John B.

On 1/1/2016 5:22 PM, John B. wrote:
On Fri, 01 Jan 2016 03:36:09 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 02:39:36 +0100


Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

But I'm not sure that is a concern as the strength of a brazed joint
is so very largely dependent on the clearance in the joint necessary
to allow the brazing metal to penetrate the joint.

Silver soldering is stiffer and more durable.

Of course, acurracy of the pieces used is a much more
decisive point.


It might also be of interest to know that many silver brazing fillers
contain Cadmium which lowers the melting point and improves fluidity,
but which also produce cadmium oxide fumes when heated above 608
degrees (F), or 320 (C). Cadmium fumes are considered poisonous and
while they have been in use for many years should be treated with
respect.

Same with red lead or zinc chromate paint.

Perfect anti-rust, but poisonous.

A bit different though. You can paint red-lead or zinc chromate with a
brush perfectly safely but all you have to do is melt cadmium silver
solder to release fumes.

Any unless you melt the silver solder it isn't any use, at all :-)

--
cheers,

John B.


Cadmium is indeed potentially dangerous but for a dramatic
and immediate effect try welding galvanized steel. Once is
plenty enough to impress the idea.

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

On Sat, 02 Jan 2016 07:17:08 -0600, AMuzi wrote:

On 1/1/2016 5:22 PM, John B. wrote:
On Fri, 01 Jan 2016 03:36:09 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 02:39:36 +0100


Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

But I'm not sure that is a concern as the strength of a brazed joint
is so very largely dependent on the clearance in the joint necessary
to allow the brazing metal to penetrate the joint.

Silver soldering is stiffer and more durable.

Of course, acurracy of the pieces used is a much more
decisive point.


It might also be of interest to know that many silver brazing fillers
contain Cadmium which lowers the melting point and improves fluidity,
but which also produce cadmium oxide fumes when heated above 608
degrees (F), or 320 (C). Cadmium fumes are considered poisonous and
while they have been in use for many years should be treated with
respect.

Same with red lead or zinc chromate paint.

Perfect anti-rust, but poisonous.

A bit different though. You can paint red-lead or zinc chromate with a
brush perfectly safely but all you have to do is melt cadmium silver
solder to release fumes.

Any unless you melt the silver solder it isn't any use, at all :-)

--
cheers,

John B.


Cadmium is indeed potentially dangerous but for a dramatic
and immediate effect try welding galvanized steel. Once is
plenty enough to impress the idea.

Yes, I helped carry a guy to the hospital with that problem and when
we got him there the doctor wanted to operate as he diagnosed the
problem as appendicitis and had the welding shop supervisor not argued
so long and loudly that it was "galvanized poisoning" they probably
would have.
--
cheers,

John B.

On 1/3/2016 1:17 AM, John B. wrote:
On Sat, 02 Jan 2016 07:17:08 -0600, AMuzi wrote:

On 1/1/2016 5:22 PM, John B. wrote:
On Fri, 01 Jan 2016 03:36:09 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 02:39:36 +0100


Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

But I'm not sure that is a concern as the strength of a brazed joint
is so very largely dependent on the clearance in the joint necessary
to allow the brazing metal to penetrate the joint.

Silver soldering is stiffer and more durable.

Of course, acurracy of the pieces used is a much more
decisive point.


It might also be of interest to know that many silver brazing fillers
contain Cadmium which lowers the melting point and improves fluidity,
but which also produce cadmium oxide fumes when heated above 608
degrees (F), or 320 (C). Cadmium fumes are considered poisonous and
while they have been in use for many years should be treated with
respect.

Same with red lead or zinc chromate paint.

Perfect anti-rust, but poisonous.

A bit different though. You can paint red-lead or zinc chromate with a
brush perfectly safely but all you have to do is melt cadmium silver
solder to release fumes.

Any unless you melt the silver solder it isn't any use, at all :-)

--
cheers,

John B.


Cadmium is indeed potentially dangerous but for a dramatic
and immediate effect try welding galvanized steel. Once is
plenty enough to impress the idea.

Yes, I helped carry a guy to the hospital with that problem and when
we got him there the doctor wanted to operate as he diagnosed the
problem as appendicitis and had the welding shop supervisor not argued
so long and loudly that it was "galvanized poisoning" they probably
would have.
--
cheers,

John B.


Zinc fumes can cause instant knee collapse and vomiting.
Quite a memorable event and, as I noted, once is enough.

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

On Sun, 03 Jan 2016 09:10:08 -0600, AMuzi wrote:

On 1/3/2016 1:17 AM, John B. wrote:
On Sat, 02 Jan 2016 07:17:08 -0600, AMuzi wrote:

On 1/1/2016 5:22 PM, John B. wrote:
On Fri, 01 Jan 2016 03:36:09 +0100, "Jakob Krieger"
wrote:

- John B. / Thu, 31 Dec 2015 02:39:36 +0100


Actually, silver soldering is a bit stronger than brass, although
clearly more expensive.

But I'm not sure that is a concern as the strength of a brazed joint
is so very largely dependent on the clearance in the joint necessary
to allow the brazing metal to penetrate the joint.

Silver soldering is stiffer and more durable.

Of course, acurracy of the pieces used is a much more
decisive point.


It might also be of interest to know that many silver brazing fillers
contain Cadmium which lowers the melting point and improves fluidity,
but which also produce cadmium oxide fumes when heated above 608
degrees (F), or 320 (C). Cadmium fumes are considered poisonous and
while they have been in use for many years should be treated with
respect.

Same with red lead or zinc chromate paint.

Perfect anti-rust, but poisonous.

A bit different though. You can paint red-lead or zinc chromate with a
brush perfectly safely but all you have to do is melt cadmium silver
solder to release fumes.

Any unless you melt the silver solder it isn't any use, at all :-)

--
cheers,

John B.


Cadmium is indeed potentially dangerous but for a dramatic
and immediate effect try welding galvanized steel. Once is
plenty enough to impress the idea.

Yes, I helped carry a guy to the hospital with that problem and when
we got him there the doctor wanted to operate as he diagnosed the
problem as appendicitis and had the welding shop supervisor not argued
so long and loudly that it was "galvanized poisoning" they probably
would have.
--
cheers,

John B.


Zinc fumes can cause instant knee collapse and vomiting.
Quite a memorable event and, as I noted, once is enough.

The humorous aspect was that the welder I mentioned was making "drip
pans" a 4 x 8 sheet of galvanized steel with a 2 inch lip bent up all
the way round and the corners brazed so they wouldn't leak.

Several people had told the guy to get a fan to blow the fumes away
and he had insisted that, "I got strong lungs".
--
cheers,

John B.

- John B. / Fri, 01 Jan 2016 12:11:15 +0100


The machines used for making bike-parts from Al alloy
are computer controlled MIG ones that work in two steps --
first drop some material to the welding point,
then do the real welding. The worker or robot arm only has
to 'point and shoot'. That's what I meant: with such equipment,
you don't need a skilled craftsman at the machine any more.

I'm not sure what you are saying. MiG welding is very like "stick" arc
welding. You start the arc and go.

Well, these automats do the most for you, while still using
MIG tech. They are more or less what welding robots do,
except for positioning.

But "automatic" welding isn't really new. I think I mentioned the guy
I worked with years ago now that spent a day, in a Detroit car factory
pushing a button to trigger an automatic welding machine that welded
the axle tubes into a differential housing, and pipe rolling mills ere
automatically welding pipe nearly that long ago. In the late 70's I
visited a spiral pipe factory in West Java that welded 40 ft joints of
pipe automatically.

Yes, but the new generations of machines are cheap, small,
and do about the same. I messed up the link address,
otherwise I could show you the kind of tool I talk about.


jk



--
no sig