Reynolds 931 "cheap stainless" -- Michael Press Prize for brilliant marketing

[Andre Jute]

http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berthoud-deda-reynolds-hope-cateye-more
and scroll down.

Reynolds 931 "cheap stainless"
Twenty per cent more than 853, ten per cent less than 951, yup, that's
brilliant marketing. Or maybe they really wanted to kill both
successful products, and still leave the customer dissatisfied with
having received only the "cheap" stainless.

[Michael Press]

In article
<48bdd208-85e6-4c73...@a13g2000yqd.googlegroups.com>,
Andre Jute <fiul...@yahoo.com> wrote:

Oh, as if I _ever_ use percent.
Those who use unbound percent
are to be broken upon the wheel,
once I am Ruler of Earth, and
that goes for my minions as well.

--
Michael Press

[thirty-six]

On Sep 9, 2:45 am, Andre Jute <fiult...@yahoo.com> wrote:
> http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...

> and scroll down.
>
> Reynolds 931 "cheap stainless"
> Twenty per cent more than 853, ten per cent less than 951, yup, that's
> brilliant marketing. Or maybe they really wanted to kill both
> successful products, and still leave the customer dissatisfied with
> having received only the "cheap" stainless.

It saves having to apply chrome plating for the shiny lovers. A
simple polished finish may work out cheaper than a proper laquered
job. I don't know the cost today, but when I enquired at the
refinishers about 15 years ago and was shocked at the price and
enquired "why?" they insisted that all frames required sand-blasting
to prepare them. I left them to their busy workbook and got the job
done myself with Hammerite and a brush. I worked out how to get the
thick stuff on without leaving gaps or brushstrokes and its stood up
very well.

[James]

I also wonder how stainless it is. But this caught my eye..
"Reynolds is also rolling out to its customers who are typically custom
framebuilders without access to sophisticated computer modelling tools a
programme called eReynolds FEA (Finite Element Analysis) which will
enable them to 'build' their frames in virtual form to test the
feasibility of tubing and joining options before expensively committing
to physical prototypes."

I wonder whether some more adventurous frame designs come about as a
result. Years ago there was a local frame builder who designed what he
called a "Compuframe", IIRC. The seat stays crossed the seat tube and
joined the top tube 4-5 inches along. Although I rode one of these
frames for a while, it didn't stand out as feeling particularly
different from the previous steel frame I had (another locally made 531
lugged frame).

--
JS.

[Jay Beattie]

On Sep 8, 7:39 pm, James <james.e.stew...@gmail.com> wrote:
> On 9/09/2011 11:45 AM, Andre Jute wrote:
>

> >http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...

> > and scroll down.
>
> > Reynolds 931 "cheap stainless"
> > Twenty per cent more than 853, ten per cent less than 951, yup, that's
> > brilliant marketing. Or maybe they really wanted to kill both
> > successful products, and still leave the customer dissatisfied with
> > having received only the "cheap" stainless.
>
> I also wonder how stainless it is.  But this caught my eye..
> "Reynolds is also rolling out to its customers who are typically custom
> framebuilders without access to sophisticated computer modelling tools a
> programme called eReynolds FEA (Finite Element Analysis) which will
> enable them to 'build' their frames in virtual form to test the
> feasibility of tubing and joining options before expensively committing
> to physical prototypes."

Right -- FEA for frame building. Most of the builders I know or have
known build off of jigs and use geometries and joinery that has been
around forever. Ain't rocket surgery, as Peter used to say. With
that said, half of the Bohemians winning the prize at the latest
"handmade bicycle" show have built maybe four frames -- but they were
super cool looking frames! Great paint, great lugs -- but gawd only
knows whether the joints are filled or the frame is over-cooked. These
guys don't need FEA. They need some shop classes.

-- Jay Beattie.

[James]

I understand what you say, however I suspect the dude that built my
current steel frame is far more savvy than the Bohemians you speak of.

http://www.gelliecustombikeframes.com.au/about-gellie-custom.htm

--
JS.

[AMuzi]

Old design. Hetchins "Hellenic Triangle"

http://www.classiclightweights.co.uk/bikes/hellenic-kh1a.jpg

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

[Frank Krygowski]

On Sep 8, 10:39 pm, James <james.e.stew...@gmail.com> wrote:
> On 9/09/2011 11:45 AM, Andre Jute wrote:
>

> >http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...

> > and scroll down.
>
> > Reynolds 931 "cheap stainless"
> > Twenty per cent more than 853, ten per cent less than 951, yup, that's
> > brilliant marketing. Or maybe they really wanted to kill both
> > successful products, and still leave the customer dissatisfied with
> > having received only the "cheap" stainless.
>
> I also wonder how stainless it is.  But this caught my eye..
> "Reynolds is also rolling out to its customers who are typically custom
> framebuilders without access to sophisticated computer modelling tools a
> programme called eReynolds FEA (Finite Element Analysis) which will
> enable them to 'build' their frames in virtual form to test the
> feasibility of tubing and joining options before expensively committing
> to physical prototypes."
>
> I wonder whether some more adventurous frame designs come about as a
> result.  Years ago there was a local frame builder who designed what he
> called a "Compuframe", IIRC.  The seat stays crossed the seat tube and
> joined the top tube 4-5 inches along.  Although I rode one of these
> frames for a while, it didn't stand out as feeling particularly
> different from the previous steel frame I had (another locally made 531
> lugged frame).

Nashbar sold a frame that fit that description in (IIRC) the early
1990s. One of my friends owns one. He bought it because it was
inexpensive, on sale.

I think it's another one of those ideas (like frames with curved seat
tubes and ultra-short wheelbases, "curly stays," "zertz" inserts,
etc.) that enjoyed some brief attention, but gave no practical
benefit.

- Frank Krygowski

[James]

Wow! That's the sort of thing.

I chatted to a mate who's got a:
http://www.bmc-racing.com/int-en/bikes/2011/road/model/racemachine/rm01/standard.html

I looked at it for a moment and said, "I bet it's comfortable." He said
it is the most comfy road bike he's ridden.

I wonder if a similar design could be made in steel, and whether it
would also be more comfortable than having the stays in the traditional
position. My guess is it allows the seat post to rotate further under
load. Only testing would reveal actual differences of course.

--
JS.

[thirty-six]

On Sep 9, 6:02 am, James <james.e.stew...@gmail.com> wrote:
> On 9/09/2011 2:35 PM, AMuzi wrote:
>
>
>
> > James wrote:
> >> On 9/09/2011 11:45 AM, Andre Jute wrote:

> >>>http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...

>
> >>> and scroll down.
>
> >>> Reynolds 931 "cheap stainless"
> >>> Twenty per cent more than 853, ten per cent less than 951, yup, that's
> >>> brilliant marketing. Or maybe they really wanted to kill both
> >>> successful products, and still leave the customer dissatisfied with
> >>> having received only the "cheap" stainless.
>
> >> I also wonder how stainless it is. But this caught my eye..
> >> "Reynolds is also rolling out to its customers who are typically
> >> custom framebuilders without access to sophisticated computer
> >> modelling tools a programme called eReynolds FEA (Finite Element
> >> Analysis) which will enable them to 'build' their frames in virtual
> >> form to test the feasibility of tubing and joining options before
> >> expensively committing to physical prototypes."
>
> >> I wonder whether some more adventurous frame designs come about as a
> >> result. Years ago there was a local frame builder who designed what he
> >> called a "Compuframe", IIRC. The seat stays crossed the seat tube and
> >> joined the top tube 4-5 inches along. Although I rode one of these
> >> frames for a while, it didn't stand out as feeling particularly
> >> different from the previous steel frame I had (another locally made
> >> 531 lugged frame).
>
> > Old design. Hetchins "Hellenic Triangle"
>
> >http://www.classiclightweights.co.uk/bikes/hellenic-kh1a.jpg
>
> Wow!  That's the sort of thing.
>

> I chatted to a mate who's got a:http://www.bmc-racing.com/int-en/bikes/2011/road/model/racemachine/rm...

>
> I looked at it for a moment and said, "I bet it's comfortable."  He said
> it is the most comfy road bike he's ridden.
>
> I wonder if a similar design could be made in steel, and whether it
> would also be more comfortable than having the stays in the traditional
> position.  My guess is it allows the seat post to rotate further under
> load.  Only testing would reveal actual differences of course.
>
> --
> JS.

You want a steel frame with pencil stays. I use one, but the wheel
has to be top notch (when one is 14st ) or things are too soft at the
back making the rear end track one way then the other when climbing at
a not too frenetic cadence. Squaring off the chainstays helps reduce
excessive flexing, but it's usually an accepted comprimise with
steel.

[Jay Beattie]

Probably very capable with his background and the fact he is TIG
welding, but still no FEA needed with those frames -- not unless he is
building with some super weird tubes, which does not appear to be the
case (Columbus and TrueTemper).

-- Jay Beattie..

[Frank Krygowski]

James wrote:
> ... Only testing would reveal actual differences of course.

Yes, if by "testing," you mean putting the bare frame into a rig that
measures deflection under various loading situations. Or providing a
totally wrapped and camouflaged frame for use in a blind comparison test.

OTOH, if the "testing" is "giving it to a freshman Bicycling journalist
who's had time to read the ads, and who wants the ads to continue," the
results are bound to be rave reviews, whether there was any difference
or not.

Editors have to sell magazines. Magazines have to sell ads. Ads have
to sell bikes.

--
- Frank Krygowski

[landotter]

Our local friendly framebuilder only has a couple dozen frames under
his belt--but he spent his first year brazing and destroying frames/
joints with a bandsaw to check for strength and even fill. Impressive.

[AMuzi]

Wow that IS impressive!

I've never built anything in steel that can hold up to a
bandsaw!

[thirty-six]

Fag paper clearance is the correct fit for braze penetration, around
0.004" around.

[Hank]

> - Frank Krygowski- Hide quoted text -
>
> - Show quoted text -

And it's a design that gets resurrected every few years by another
manufacturer. My dad's 1986 Shogun (Tange MTB Cr-Mo) had it, and my
2003 GT (7005 Al) has it.

[Andre Jute]

On Sep 9, 6:02 am, James <james.e.stew...@gmail.com> wrote:

> On 9/09/2011 2:35 PM, AMuzi wrote:
>
>
>
>
>
> > James wrote:
> >> On 9/09/2011 11:45 AM, Andre Jute wrote:

> >>>http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...

>
> >>> and scroll down.
>
> >>> Reynolds 931 "cheap stainless"
> >>> Twenty per cent more than 853, ten per cent less than 951, yup, that's
> >>> brilliant marketing. Or maybe they really wanted to kill both
> >>> successful products, and still leave the customer dissatisfied with
> >>> having received only the "cheap" stainless.
>
> >> I also wonder how stainless it is. But this caught my eye..
> >> "Reynolds is also rolling out to its customers who are typically
> >> custom framebuilders without access to sophisticated computer
> >> modelling tools a programme called eReynolds FEA (Finite Element
> >> Analysis) which will enable them to 'build' their frames in virtual
> >> form to test the feasibility of tubing and joining options before
> >> expensively committing to physical prototypes."
>
> >> I wonder whether some more adventurous frame designs come about as a
> >> result. Years ago there was a local frame builder who designed what he
> >> called a "Compuframe", IIRC. The seat stays crossed the seat tube and
> >> joined the top tube 4-5 inches along. Although I rode one of these
> >> frames for a while, it didn't stand out as feeling particularly
> >> different from the previous steel frame I had (another locally made
> >> 531 lugged frame).
>
> > Old design. Hetchins "Hellenic Triangle"
>
> >http://www.classiclightweights.co.uk/bikes/hellenic-kh1a.jpg
>
> Wow!  That's the sort of thing.
>

> I chatted to a mate who's got a:http://www.bmc-racing.com/int-en/bikes/2011/road/model/racemachine/rm...

>
> I looked at it for a moment and said, "I bet it's comfortable."  He said
> it is the most comfy road bike he's ridden.
>
> I wonder if a similar design could be made in steel, and whether it
> would also be more comfortable than having the stays in the traditional
> position.  My guess is it allows the seat post to rotate further under
> load.  Only testing would reveal actual differences of course.
>
> --
> JS.

I can't say I'm impressed by the length of unsupported seat tube
between where the seatstays join and where the brace joins. It's a
recipe for flex and/or unnecessary weight in the material. Any proper
engineer and any artist would give that construction one look and ask
if the flex is intentional. If not, he'd move the brace or the
seatstays so that the ends me across the seat tube.

Here are some properly designed crossframe bikes
http://www.utopia-velo.de/relaunch/index.a4d
I especially like the Roadster.

Andre Jute
Steel is real, a Brooks hammock seat makes it better, BIg Apples
better still

[Peter Cole]

GT MTB's have used it forever, e.g.:

http://3.bp.blogspot.com/_LpsggR4DbkE/S3VXoT2qZBI/AAAAAAAAAAk/4OZRu536r_Y/s400/gt-mountain-bike.jpg

I have one, and it doesn't ride any differently, I wouldn't expect it
to, as that joint is probably the stiffest on a diamond frame. It's not
particularly stressed, either, so I wouldn't expect any effect on frame
life. Just a stylistic affectation, a harmless one.

[Frank Krygowski]

John B. wrote:

> On Fri, 9 Sep 2011 10:25:51 -0700 (PDT), landotter
> <land...@gmail.com> wrote:
>
>>
>> Our local friendly framebuilder only has a couple dozen frames under
>> his belt--but he spent his first year brazing and destroying frames/
>> joints with a bandsaw to check for strength and even fill. Impressive.
>
>

> Frankly that seems like over-kill. Assuming that he started out
> understanding that the joint needed to be completely brazed one would
> think that a couple of joint would be sufficient to ensure that he was
> doing it correctly.

... unless he found he wasn't doing it correctly, and it took many
trials to get it right!


--
- Frank Krygowski

[Dan O]

> http://3.bp.blogspot.com/_LpsggR4DbkE/S3VXoT2qZBI/AAAAAAAAAAk/4OZRu53...

>
> I have one, and it doesn't ride any differently, I wouldn't expect it
> to, as that joint is probably the stiffest on a diamond frame. It's not
> particularly stressed, either, so I wouldn't expect any effect on frame
> life. Just a stylistic affectation, a harmless one.

Speaking of weird stays, there's one of these parking in the rack
outside where I work - set up for touring duty w/ drop bars:

http://www.retrobike.co.uk/forum/files/nishiki_alien_sale_3_143.jpg

[AMuzi]

undocumented feature:
Needs neither a snaplink nor a chain rivet tool to remove
and reinstall the chain.

[thirty-six]

On Sep 10, 12:56 pm, John B. <johnbsloc...@gmail.com> wrote:
> On Fri, 9 Sep 2011 12:01:46 -0700 (PDT), thirty-six

> While you are not incorrect it might be noted that some brazing rod is
> capable of gap filling and can be used with significantly wider
> fit-ups.

They'll be no capillary action, a cosmetic job. Wider joints, even
when filled, do not have the same sort of strength.

[AMuzi]

from:
http://www.aws.org/wj/amwelder/9-00/fundamentals.html

"A braze alloy relies on capillary action to distribute the
brazing filler metal throughout the joint interface.
Capillary action is the force that pulls a liquid through
two parallel surfaces. In brazing, the clearance at which
capillary action is most effective is in the 0.001- to
0.005-in. range.

Joint clearance also has a profound impact on joint
strength. Figure 2 shows how the tensile strength of a
stainless steel brazed joint varies with the amount of
clearance between the parts being joined. Note that the
strongest joint (135,000 lb/in.2 [930.8 MPa]) is achieved
when the joint clearance is 0.0015 in. (0.038 mm). When the
clearance is narrower, it is difficult for the filler metal
to distribute itself adequately throughout the entire joint,
reducing joint strength. Conversely, if the joint clearance
is wider than necessary, the strength of the joint will be
reduced almost to that of the filler metal itself.

Translated into everyday shop practice - an easy slip fit
will give you a perfectly adequate brazed joint between two
tubular parts.

[thirty-six]

I'll apologise in that I was considering carbon steel and mang-moly
steel frames with the usual brass spelter/rods. I jumped in without
thinking about the implications of this particular tube material and
possibly necessary silver solder. Whether such consistent tolerances
can be obtained with frame-building is another matter. I feel it
possibly unlikely that many of these tubesets will be made up with
lugs.

[Frank Krygowski]

On Sep 11, 1:10 am, John B. <johnbsloc...@gmail.com> wrote:
> On Sat, 10 Sep 2011 13:01:33 -0400, Frank Krygowski

>
>
>
> <frkrygowREM...@gEEmail.com> wrote:
> >John B. wrote:
> >> On Fri, 9 Sep 2011 10:25:51 -0700 (PDT), landotter

> >> <landot...@gmail.com>  wrote:

>
> >>> Our local friendly framebuilder only has a couple dozen frames under
> >>> his belt--but he spent his first year brazing and destroying frames/
> >>> joints with a bandsaw to check for strength and even fill. Impressive.
>
> >> Frankly that seems like over-kill. Assuming that he started out
> >> understanding that the joint needed to be completely brazed one would
> >> think that a couple of joint would be sufficient to ensure that he was
> >> doing it correctly.
>
> >... unless he found he wasn't doing it correctly, and it took many
> >trials to get it right!
>

> Brazing socketed joints is not rocket science. Plumbers installing
> copper pipe do it all day - ever hear about a plumber spending two
> years practicing before he fixes the broken pipe in your bathroom?

Strictly speaking, soft soldering is not the same as brazing. Not
only are temperatures much lower for soldering, but required strength
of a soldered joint is low. And there's little chance of damaging the
strength of the parent metal by overheating.

Having done both, I believe brazing is considerably more difficult. I
wouldn't hand a plumber some thin walled alloy steel tubing, some
lugs, and his first oxy-acetylene torch and trust the first bike he
built with them.

- Frank Krygowski

[DougC]

On 9/10/2011 2:45 PM, AMuzi wrote:
>
>
> from:
> http://www.aws.org/wj/amwelder/9-00/fundamentals.html
>
>
> "A braze alloy relies on capillary action to distribute the brazing
> filler metal throughout the joint interface. Capillary action is the
> force that pulls a liquid through two parallel surfaces. In brazing, the
> clearance at which capillary action is most effective is in the 0.001-
> to 0.005-in. range.
>
> Joint clearance also has a profound impact on joint strength. Figure 2
> shows how the tensile strength of a stainless steel brazed joint varies
> with the amount of clearance between the parts being joined. Note that
> the strongest joint (135,000 lb/in.2 [930.8 MPa]) is achieved when the

> joint clearance is 0.0015 in. (0.038 mm). ....
>
> .... Translated into everyday shop practice - an easy slip fit will give you

> a perfectly adequate brazed joint between two tubular parts.
>

Is that .001"-.005" figure per-side, or total difference? I dunno ducks
about brazing much, especially with silver/nickel/whatever stuff.

It is my understanding in machinist practice that a slip-fit is usually
regarded to be .001" total difference, or .0005" per side. Over-under
reamers are sold .001" over or under.

If you use .001" total, the parts are difficult to fit if there's any
edge burrs and it's damn difficult to just get the pieces lined up
straight in larger sizes--beyond 2-3 inches--without using some kind of
guide machinery.

[DougC]

On 9/10/2011 12:17 AM, Andre Jute wrote:
>....

>
> Here are some properly designed crossframe bikes
> http://www.utopia-velo.de/relaunch/index.a4d
> I especially like the Roadster.
>

It looks wrong to me.
Metal being stronger in tension than compression,,,, the tubes running
between the head tube bottom and the rear dropouts should be the
thickest (since they are in compression) with all the others thinner.

Except for the seat tube which must be a minimum dia of course, to take
a common seatpost....

[DougC]

Wait,,, nevermind.
Browser defaults to the pic of the Kranich. I thought that was what you
were talking about.

Interesting that they still offer a "normal" looking frame, and a
recumbent as well.

[Frank Krygowski]

John B. wrote:

> On Sat, 10 Sep 2011 22:35:04 -0700 (PDT), Frank Krygowski
> <frkr...@gmail.com> wrote:
>
>> Strictly speaking, soft soldering is not the same as brazing. Not
>> only are temperatures much lower for soldering, but required strength
>> of a soldered joint is low. And there's little chance of damaging the
>> strength of the parent metal by overheating.
>>
>> Having done both, I believe brazing is considerably more difficult. I
>> wouldn't hand a plumber some thin walled alloy steel tubing, some
>> lugs, and his first oxy-acetylene torch and trust the first bike he
>> built with them.
>>
>> - Frank Krygowski
>

> The process of melting the filler metal and gradually wicking it
> through the joint is exactly the same.

Except that to prevent a leak, you need a good metallurgical bond around
just one continuous circumference of the pipe, anywhere in the joint.
It could be as narrow as an O-ring. To get full strength in a
structural brazed joint between a bike frame tube and a lug, the braze
filler material should fill all the space between tube and lug.

>
> And, I hate to be crude but the whole thing about overheating the
> metal, burning the steel, and so on is simply the moaning of the
> inexperienced....

Which is why it's reasonable for an inexperienced person to do some test
joints, then cut them apart to see if they did it right.

Perhaps testing by destructive inspection might not be the only way to
give the student feedback. But it's a good one. I know it's done when
teaching welding, so I assume it's common when teaching brazing.

--
- Frank Krygowski

[Dan O]

On Sep 11, 8:35 am, Frank Krygowski <frkrygowREM...@gEEmail.com>
wrote:

The bike that I chopped up to add rear suspension at age 13 was
originally an ordinary, typical, cheap kids bike of the time (coaster
brake, banana seat, high rise handlebars) purchased with S&H Green
Stamps about 5 years earlier. I cut the seat stays and chain stays,
fabricated a swingarm pivot behind the bottom bracket, shock mount at
top of seat stays, shocjk mount between top and down tubes - no lugs -
all brazed joints. I rode that thing as hard as I could on the
roughest stuff I could find, was getting to be a big boy by then, and
none of the joints failed. (I did start to wear out the very
primitive swingarm hinge, so my next one used replaceable bronze
bushings there).

Since BMX handlebars were still rare at that time, and their cross bar
would require either a BMX stem or prying open the quill stem clamp
(which I eventually did a time or two), I cut the original chrome
plated high rise handlebars into 5 pieces and brazed *them* back
together to make BMX-like bars with no cross bar. These held up under
a lot hard riding, but eventually one of the handlebar joints did let
go (was whjeelying at the time, too - whjee :-) - and somehow didn't
crash). I think the problem here may have been at least in part that
I only ground a taper for the joints without taking the chrome off far
enough back... that and maybe the idiocy of a handlebar with
unreinforced brass joints. The broken joint didn't look flawed; it
just was what it was - and broken.

[AMuzi]

John B. wrote:
> On Sat, 10 Sep 2011 22:35:04 -0700 (PDT), Frank Krygowski

> The process of melting the filler metal and gradually wicking it
> through the joint is exactly the same.
>

> And, I hate to be crude but the whole thing about overheating the
> metal, burning the steel, and so on is simply the moaning of the

> inexperienced. It is not as though people haven't been fitting up
> tubing joints and sticking them together for what? 90 years? 100
> years? And brazing has been going on for an even longer period.
>

I recently replaced two tubes in a 1919 built lugged USA frame.

Original braze work was good, no problems.

Arguably 'better than new' because the original 0.9 tubes
were brass-seamed mild steel. I used seamless Deda CrMo.

[thirty-six]

Plumbers also braze.

[cl...@snyder.on.ca]

On Sun, 11 Sep 2011 12:10:27 +0700, John B. <johnbs...@gmail.com>
wrote:

>On Sat, 10 Sep 2011 13:01:33 -0400, Frank Krygowski

>Brazing socketed joints is not rocket science. Plumbers installing
>copper pipe do it all day - ever hear about a plumber spending two
>years practicing before he fixes the broken pipe in your bathroom?

Plumbers do not BRAZE plumbing, they SOLDER it. Similar process,
but different enough to be significant.

Making bike frames is easiest with brazing paste - as used in "furnace
brazing". Smear it on, put the joint together, mark the joint with a
temp crayon, and heat untill the proper temp is reached (indicated by
the crayon "going off") and the job is done.

[thirty-six]

"Plumbers" also have difficulty with chromed pipes.

[Andy Morris]

On 10/09/2011 19:48, Dan O wrote:

>
> Speaking of weird stays, there's one of these parking in the rack
> outside where I work - set up for touring duty w/ drop bars:
>
> http://www.retrobike.co.uk/forum/files/nishiki_alien_sale_3_143.jpg

They where done like that to prevent the problem of the chain getting
stuck between the tyre and chainstay and to avoid mud building up
between the chainstays.

--
Andy Morris
Andy dot Jinkas at Googlemail

[James]

On 10/09/2011 12:30 AM, Jay Beattie wrote:
> On Sep 8, 9:02 pm, James<james.e.stew...@gmail.com> wrote:

>> I understand what you say, however I suspect the dude that built my
>> current steel frame is far more savvy than the Bohemians you speak of.
>>
>> http://www.gelliecustombikeframes.com.au/about-gellie-custom.htm
>
> Probably very capable with his background and the fact he is TIG
> welding, but still no FEA needed with those frames -- not unless he is
> building with some super weird tubes, which does not appear to be the
> case (Columbus and TrueTemper).

The point being FEA capability allows some room for experimentation
before building and testing, if that is what someone wants. The
Reynolds FEA tool is for custom frame builders, some of whom do not only
build standard frame designs.

I don't see the availability of FEA as a bad thing, regardless of
whether it is "necessary" or not.

--
JS

[James]

On 10/09/2011 3:17 PM, Andre Jute wrote:
> On Sep 9, 6:02 am, James<james.e.stew...@gmail.com> wrote:
>> On 9/09/2011 2:35 PM, AMuzi wrote:

>>
>>
>>
>>
>>
>>> James wrote:
>>>> On 9/09/2011 11:45 AM, Andre Jute wrote:
>>>>> http://road.cc/content/news/43047-more-eurobike-goodness-gilles-berth...
>>
>>>>> and scroll down.
>>
>>>>> Reynolds 931 "cheap stainless"
>>>>> Twenty per cent more than 853, ten per cent less than 951, yup, that's
>>>>> brilliant marketing. Or maybe they really wanted to kill both
>>>>> successful products, and still leave the customer dissatisfied with
>>>>> having received only the "cheap" stainless.
>>
>>>> I also wonder how stainless it is. But this caught my eye..
>>>> "Reynolds is also rolling out to its customers who are typically
>>>> custom framebuilders without access to sophisticated computer
>>>> modelling tools a programme called eReynolds FEA (Finite Element
>>>> Analysis) which will enable them to 'build' their frames in virtual
>>>> form to test the feasibility of tubing and joining options before
>>>> expensively committing to physical prototypes."
>>

>>>> I wonder whether some more adventurous frame designs come about as a
>>>> result. Years ago there was a local frame builder who designed what he
>>>> called a "Compuframe", IIRC. The seat stays crossed the seat tube and
>>>> joined the top tube 4-5 inches along. Although I rode one of these
>>>> frames for a while, it didn't stand out as feeling particularly
>>>> different from the previous steel frame I had (another locally made
>>>> 531 lugged frame).
>>

>>> Old design. Hetchins "Hellenic Triangle"
>>
>>> http://www.classiclightweights.co.uk/bikes/hellenic-kh1a.jpg
>>
>> Wow! That's the sort of thing.
>>
>> I chatted to a mate who's got a:http://www.bmc-racing.com/int-en/bikes/2011/road/model/racemachine/rm...
>>
>> I looked at it for a moment and said, "I bet it's comfortable." He said
>> it is the most comfy road bike he's ridden.
>>
>> I wonder if a similar design could be made in steel, and whether it
>> would also be more comfortable than having the stays in the traditional
>> position. My guess is it allows the seat post to rotate further under
>> load. Only testing would reveal actual differences of course.
>>
>
> I can't say I'm impressed by the length of unsupported seat tube
> between where the seatstays join and where the brace joins. It's a
> recipe for flex and/or unnecessary weight in the material. Any proper
> engineer and any artist would give that construction one look and ask
> if the flex is intentional. If not, he'd move the brace or the
> seatstays so that the ends me across the seat tube.

Precisely. I believe the flex *is* intentional.

> Here are some properly designed crossframe bikes
> http://www.utopia-velo.de/relaunch/index.a4d
> I especially like the Roadster.

I didn't see that coming ;-)

--
JS.

[Frank Krygowski]

James wrote:
>
>
> The point being FEA capability allows some room for experimentation
> before building and testing, if that is what someone wants. The Reynolds
> FEA tool is for custom frame builders, some of whom do not only build
> standard frame designs.
>
> I don't see the availability of FEA as a bad thing, regardless of
> whether it is "necessary" or not.

It'll be interesting to see how many frame builders make use of it. The
intersection of the sets of those who build custom frames with those who
can use FEA may be a small one.

Way back in the late '80s or early '90s I attended a lecture by a custom
frame builder. He was talking about his tandem frames, which (IIRC)
featured some tubes he'd ovalized in a press. He said something like "I
believe this will give more torsional resistance along with more ride
comfort."

I offered to model the frames in FEA to get at least a rough idea about
whether his belief was correct, but I got the idea he didn't know what
FEA was. He certainly wasn't much interested.

--
- Frank Krygowski

[thirty-six]

On Sep 12, 12:54 am, Frank Krygowski <frkrygowREM...@gEEmail.com>
wrote:

> James wrote:
>
> > The point being FEA capability allows some room for experimentation
> > before building and testing, if that is what someone wants. The Reynolds
> > FEA tool is for custom frame builders, some of whom do not only build
> > standard frame designs.
>
> > I don't see the availability of FEA as a bad thing, regardless of
> > whether it is "necessary" or not.
>
> It'll be interesting to see how many frame builders make use of it.  The
> intersection of the sets of those who build custom frames with those who
> can use FEA may be a small one.
>
> Way back in the late '80s or early '90s I attended a lecture by a custom
> frame builder.  He was talking about his tandem frames, which (IIRC)
> featured some tubes he'd ovalized in a press.  He said something like "I
> believe this will give more torsional resistance along with more ride
> comfort."

What did the measurements show?

[thirty-six]

Technica;l;ly gpopod, but aesthetica;l;ly appa;ling#. POpop's I
spi;lt my ;lemponade#.

[David Scheidt]

John B. <johnbs...@gmail.com> wrote:

:In fact, thinking the matter over, I can't see how cutting a weld
:would show much about the weld that you couldn't see from the surface.
:Certainly you can see undercutting, lack of penetration, insufficient
:filler and uneven ripple from the surface.

I hope to god you're not in the welding business! There are huge
numbers of failures that aren't visible by visiible inspection.
There are entire companies devoted to making X-ray, ultrasonic,
magnetic, and more exotic methods of inspection. It's quite common to
cut a joint apart to show the welder what he didn't do right, even if
the defect is visible by eyeball.



--
sig 112

[David Scheidt]

John B. <johnbs...@gmail.com> wrote:

:>Making bike frames is easiest with brazing paste - as used in "furnace

:>brazing". Smear it on, put the joint together, mark the joint with a
:>temp crayon, and heat untill the proper temp is reached (indicated by
:>the crayon "going off") and the job is done.

:I'd never thought of that. what oven brazing I've seen used
:temperature controlled ovens.

Even when putting things through an oven, it's not uncommon to mark
parts with two temperature crayons, one for the right temperature, and
one for too hot. If the too hot crayon melts, your oven is screwed
up. If the the correct temperature one doesn't melt, your oven is
screwed up. Some of these products have well established time-to-melt
properties, so you can verify it was held at the right temperature for
long enough. What the shop does depends on what equipment they have,
and what they're working on.

--
Movable type was evidently a fad. --Amanda Walker

[thirty-six]

On Sep 12, 1:04 pm, John B. <johnbsloc...@gmail.com> wrote:
> On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt
>
> <dsche...@panix.com> wrote:

> I was not in the welding business per se, I was in the business of
> building pipelines, gathering stations, crude oil processing and gas
> plants and I suggest that I am reasonably well  informed about
> possible weld discrepancies. There are not "huge numbers of failures
> that..."  in fact assuming a qualified welder you find relatively few
> bad welds, usually undercutting, insufficient penetration on single
> sided welds, or slag inclusions. The normal weld inspection is x-ray,
> not magnetic (I assume you mean magnaflux), ultrasonic, or more exotic
> methods... and in fact magnaflux is used to discover cracks rather
> then to inspect welds.
>
> I'm not sure when you saw a weld "cut to show the welder...." but I've
> never seen it done, and I've been the business for more then a few
> years. I can't imagine why it would be done. After all the welder will
> have seen the x-ray films, marked his template(s) with the location of
> the defects in order to grind them out. Why would the weld be cut?
>
> --
> John B.

New live weekly networked gameshow "Who's weld was this?" with
premium line voting. They'll show anything.

[Frank Krygowski]

John B. wrote:

> On Sun, 11 Sep 2011 11:35:26 -0400, Frank Krygowski
> <frkrygo...@gEEmail.com> wrote:
>
>> John B. wrote:
>>> On Sat, 10 Sep 2011 22:35:04 -0700 (PDT), Frank Krygowski
>>> <frkr...@gmail.com> wrote:
>>>
>>>> Strictly speaking, soft soldering is not the same as brazing. Not
>>>> only are temperatures much lower for soldering, but required strength
>>>> of a soldered joint is low. And there's little chance of damaging the
>>>> strength of the parent metal by overheating.
>>>>
>>>> Having done both, I believe brazing is considerably more difficult. I
>>>> wouldn't hand a plumber some thin walled alloy steel tubing, some
>>>> lugs, and his first oxy-acetylene torch and trust the first bike he
>>>> built with them.
>>>>
>>>> - Frank Krygowski
>>>
>>> The process of melting the filler metal and gradually wicking it
>>> through the joint is exactly the same.
>>
>> Except that to prevent a leak, you need a good metallurgical bond around
>> just one continuous circumference of the pipe, anywhere in the joint.
>> It could be as narrow as an O-ring. To get full strength in a
>> structural brazed joint between a bike frame tube and a lug, the braze
>> filler material should fill all the space between tube and lug.
>>
>

> Except that the technique used is exactly the same. One fluxes and
> heats the joint until the flux melts and then applies the filler until
> the filler flows. If a joint where one can see both ends one flows the
> solder until it completely penetrates the joint and can be seen at
> both ends; if a closed end joint one usually can estimate penetration
> in the joint from the color.
>
> You can pare cheese as much as you like but it is the same technique
> with the exception that the bicycle lugged joints are a bit easier to
> get a truly 100% brazed joint as it is easier to see both ends of the
> joint.

I think we should let someone like Andrew Muzi comment on whether
brazing a bike frame is as easy as soldering copper pipes. My
experience with the former is limited, especially on thin walled tubing;
but to me it seems much more difficult than the latter, which I've done
many times.

>>> And, I hate to be crude but the whole thing about overheating the
>>> metal, burning the steel, and so on is simply the moaning of the
>>> inexperienced....
>>
>> Which is why it's reasonable for an inexperienced person to do some test
>> joints, then cut them apart to see if they did it right.
>>

> I wouldn't disagree, but the discussion was about a bloke who spent a
> year, or more, cutting joints to see whether he did a good job. Even
> for a neophyte that seems like overkill; or perhaps a chap trying to
> impress the uninitiated.

While I don't know the details, I doubt the year's work was full time,
brazing and cutting. My guess would be that the guy was learning on his
own, self-taught, and building his skills slowly on a very part-time
basis. Probably not so much to impress customers as to just get it right.

>
>> Perhaps testing by destructive inspection might not be the only way to
>> give the student feedback. But it's a good one. I know it's done when
>> teaching welding, so I assume it's common when teaching brazing.
>

> When I was a lad the idea was first to get a good looking weld - the
> creed was that a good looking weld was a good weld - and only after
> one had mastered the technique were joints inspected, and even then I
> don't remember ever cutting a joint apart. Usually bend testing was
> the testing method and even 20 years ago mechanical testing was
> usually all that was done for certification.

Bend testing is destructive, of course. And FWIW, I worked for a while
at a tech school that had a welding program. My students took the
introductory course, and they absolutely had to hammer their first welds
apart. I suppose different teachers might use different methods.

--
- Frank Krygowski

[AMuzi]

Sorry I don't think I can answer that.

I braze in both silver and bronze, and fill dents with lead,
regularly.
I less often gas or electric weld. I'm very skilled at gas
welding in thin steel but much less so with sticks, heavier
material car work mostly.

These processes are different. Each has it's own foibles.

I find leaded copper pipe work brainlessly simple and quick
but most of the ones I've done were redos for guys who had
already botched them.

Aluminum and titanium are things I only know in theory,
never welded either.

[James]

John B. wrote:
> On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt

> I was not in the welding business per se, I was in the business of
> building pipelines, gathering stations, crude oil processing and gas
> plants and I suggest that I am reasonably well informed about
> possible weld discrepancies. There are not "huge numbers of failures
> that..." in fact assuming a qualified welder you find relatively few
> bad welds, usually undercutting, insufficient penetration on single
> sided welds, or slag inclusions. The normal weld inspection is x-ray,
> not magnetic (I assume you mean magnaflux), ultrasonic, or more exotic
> methods... and in fact magnaflux is used to discover cracks rather
> then to inspect welds.
>
> I'm not sure when you saw a weld "cut to show the welder...." but I've
> never seen it done, and I've been the business for more then a few
> years. I can't imagine why it would be done. After all the welder will
> have seen the x-ray films, marked his template(s) with the location of
> the defects in order to grind them out. Why would the weld be cut?
>

IIRC, frame builders who wanted to use 753 had to provide sample welds
to Reynolds for approval. I have no idea how Reynolds inspected them
though.

--
JS.

["\"T°m Sherm@n >]

On 9/12/2011 5:10 PM, James wrote:
>[...]

> IIRC, frame builders who wanted to use 753 had to provide sample welds
> to Reynolds for approval. I have no idea how Reynolds inspected them
> though.
>

I believe submitting a sample of welded 753 to Reynolds was an automatic
failure, since the only approved way of joining 753 was silver brazing.

--
Tºm Shermªn - 42.435731°N, 83.985007°W
I am a vehicular cyclist.

["\"T°m Sherm@n >]

On 9/11/2011 8:09 PM, John B. wrote:
> [...]

> When I was a lad the idea was first to get a good looking weld - the
> creed was that a good looking weld was a good weld - and only after
> one had mastered the technique were joints inspected, and even then I
> don't remember ever cutting a joint apart. Usually bend testing was
> the testing method and even 20 years ago mechanical testing was
> usually all that was done for certification.
>

Pretty much all welded moment connections in structural steel and
critical process piping are inspected by UT (ultrasonic testing) these
days (in the US, at least).

> In fact, thinking the matter over, I can't see how cutting a weld
> would show much about the weld that you couldn't see from the surface.
> Certainly you can see undercutting, lack of penetration, insufficient
> filler and uneven ripple from the surface.

Plenty of "good looking" welds can still have internal flaws.

["\"T°m Sherm@n >]

On 9/12/2011 7:04 AM, John B. wrote:
> On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt
> <dsch...@panix.com> wrote:
>

> I was not in the welding business per se, I was in the business of
> building pipelines, gathering stations, crude oil processing and gas
> plants and I suggest that I am reasonably well informed about
> possible weld discrepancies. There are not "huge numbers of failures
> that..." in fact assuming a qualified welder you find relatively few
> bad welds, usually undercutting, insufficient penetration on single
> sided welds, or slag inclusions.

In the hydrocarbon and mineral extraction industries, spills and worker
deaths are considered part of the cost of doing business, especially in
(but not limited to) the "developing" countries where enforcement of
labor protection standards are weak and legal penalties small.

> The normal weld inspection is x-ray,
> not magnetic (I assume you mean magnaflux), ultrasonic, or more exotic
> methods... and in fact magnaflux is used to discover cracks rather
> then to inspect welds.

Not for field welded structural steel and process piping in the US,
where UT (ultrasonic) predominates.

[David Scheidt]

John B. <johnbs...@gmail.com> wrote:
:On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt
:<dsch...@panix.com> wrote:

:I was not in the welding business per se, I was in the business of

:building pipelines, gathering stations, crude oil processing and gas
:plants and I suggest that I am reasonably well informed about
:possible weld discrepancies. There are not "huge numbers of failures
:that..." in fact assuming a qualified welder you find relatively few
:bad welds, usually undercutting, insufficient penetration on single

:sided welds, or slag inclusions. The normal weld inspection is x-ray,

:not magnetic (I assume you mean magnaflux), ultrasonic, or more exotic
:methods... and in fact magnaflux is used to discover cracks rather
:then to inspect welds.

Magnafluxing (and other magnetic tests), penetrating dye,
and eddy current detectors are all used to determine weld soundness.
So is ultrasound, which has the advantage over xrays of not requiring
access to both sides of the inspected piece. No one method of
inspection is suitable for all materials or processes or products.

:I'm not sure when you saw a weld "cut to show the welder...." but I've

:never seen it done, and I've been the business for more then a few
:years. I can't imagine why it would be done. After all the welder will

Well, you keep demonstrating your lack of imagination, but it's part
of not a few welding curicula. Destructive testing is also done to
empiraclly establish what flaws are acceptable.


--
sig 49

[thirty-six]

On Sep 13, 1:22 am, "T°m Sherm@n" <""twshermanREMOVE\"@THI

I don't remember silver brazing to be essential to the method, it was
just that it meant the monkies hadn't brazed up.

[thirty-six]

On Sep 13, 1:46 am, David Scheidt <dsche...@panix.com> wrote:

> John B. <johnbsloc...@gmail.com> wrote:
>
> :On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt
>

> :<dsche...@panix.com> wrote:

ReTS : Reverberative true sonic testing.
Slam it with a hammer and if it rings like Big Ben it's fpoked.
Essential items for testing. A mason's hammer and good tuneful ears.
:-)

[David Scheidt]

John B. <johnbs...@gmail.com> wrote:
:On Tue, 13 Sep 2011 00:46:05 +0000 (UTC), David Scheidt

:<dsch...@panix.com> wrote:

:>John B. <johnbs...@gmail.com> wrote:

:>:On Mon, 12 Sep 2011 01:49:40 +0000 (UTC), David Scheidt

:Magnaflux, die checks and eddy current are all crack testing
:procedures.

Yeah, so fucking what? You don't think that people who make welded
equipment don't care about cracking? Dye penetration is used for leak
testing of some pressure vessels, too, as it can find a smaller hole
than a static pressure test.

:Ultrasonic could be used, my question was how do you record the
:position of the defects to allow repair.

We've got these things called 'computers'. They do lots of
computations on the echos, including putting together different
images, and, in top end systems, can produce a much better 3-D picture
of the joint than an X-ray picture. (I've never heard of an Xray CT
machine for weld inspection, but I supose someone may have one.)

:X-ray checking of pipe does not require access to both sides of the
:pipe. In fact, with really good welding crews the x-ray crew may be
:100 joints behind the welding crews.

Every Xray imaging device I've ever seen or heard of uses the
transmission of xrays through the target, with the except of surface
scanning stuff (as used for peep shows at airports), which are not
useful for weld inspection. That requires access to both sides of the
thing you're X-raying: emitter on one side, detector on the other.


--
sig 38

[Frank Krygowski]

John B. wrote:
> On Mon, 12 Sep 2011 13:04:27 -0400, Frank Krygowski

> My point wasn't that doing this is as "easy" as doing that, but rather
> a comment on the technique, although other then the problem of joining
> a thicker, or more massive, section to a thinner section I actually
> see little difference. .

>
>>>>> And, I hate to be crude but the whole thing about overheating the
>>>>> metal, burning the steel, and so on is simply the moaning of the
>>>>> inexperienced....
>>>>
>>>> Which is why it's reasonable for an inexperienced person to do some test
>>>> joints, then cut them apart to see if they did it right.
>>>>
>>> I wouldn't disagree, but the discussion was about a bloke who spent a
>>> year, or more, cutting joints to see whether he did a good job. Even
>>> for a neophyte that seems like overkill; or perhaps a chap trying to
>>> impress the uninitiated.
>>
>> While I don't know the details, I doubt the year's work was full time,
>> brazing and cutting. My guess would be that the guy was learning on his
>> own, self-taught, and building his skills slowly on a very part-time
>> basis. Probably not so much to impress customers as to just get it right.
>>

> I have no idea, but even if totally ignorant of the craft a year seems
> a long time to learn a technique.

It depends on what knowledge or skill you start with, and on how many
hours you devote to the learning. "A year" could be one trial a month,
for all we know. In fact, that's more likely than dropping out of a
previous full time job to spend 2000 hours doing trial-and-error brazing
on zero salary.

>
>>>
>>>> Perhaps testing by destructive inspection might not be the only way to
>>>> give the student feedback. But it's a good one. I know it's done when
>>>> teaching welding, so I assume it's common when teaching brazing.
>>>
>>> When I was a lad the idea was first to get a good looking weld - the
>>> creed was that a good looking weld was a good weld - and only after
>>> one had mastered the technique were joints inspected, and even then I
>>> don't remember ever cutting a joint apart. Usually bend testing was
>>> the testing method and even 20 years ago mechanical testing was
>>> usually all that was done for certification.
>>
>> Bend testing is destructive, of course. And FWIW, I worked for a while
>> at a tech school that had a welding program. My students took the
>> introductory course, and they absolutely had to hammer their first welds
>> apart. I suppose different teachers might use different methods.
>

> Hammering welds to see what breaks is somewhat different from "cutting
> welds apart to show the welder..." as one writer had it.

Sure. But I'm not limiting myself to what that one writer said. I'm
talking about what I, personally, saw happen.

> And people
> taking an introductory course are far from being people who would
> (hopefully) be constructing things from double butted tubes.

You're losing track of the fact that this sub-thread was triggered by
accounts of a frame builder learning his craft. Every frame builder
starts out as a novice, constructing his first ever joint using double
butted tubes.

> I have no idea what type of welding you were teaching but the usual
> practice for gas or arc is to teach the student to run a "pretty" bead
> - even ripple, correct amount of fill, no undercut, proper
> penetration, etc., and then after he learns what is mainly the
> mechanical part of welding to do some bend tests, etc.

To be clear: I wasn't teaching the welding. I was teaching engineering.
But my students (at least most of them) took one hands-on course in
welding.

--
- Frank Krygowski

[thirty-six]

On Sep 13, 1:12 pm, John B. <johnbsloc...@gmail.com> wrote:
> On Mon, 12 Sep 2011 19:24:58 -0500, "T°m Sherm@n"

>
> <""twshermanREMOVE\"@THI$southslope.net"> wrote:
> >On 9/11/2011 8:09 PM, John B. wrote:
> > > [...]
> >> When I was a lad the idea was first to get a good looking weld - the
> >> creed was that a good looking weld was a good weld - and only after
> >> one had mastered the technique were joints inspected, and even then I
> >> don't remember ever cutting a joint apart. Usually bend testing was
> >> the testing method and even 20 years ago mechanical testing was
> >> usually all that was done for certification.
>
> >Pretty much all welded moment connections in structural steel and
> >critical process piping are inspected by UT (ultrasonic testing) these
> >days (in the US, at least).
>

> Not to argue, but are you sure?  Is there some kind of printed readout
> so that the defects can be located for repair?

>
> >> In fact, thinking the matter over, I can't see how cutting a weld
> >> would show much about the weld that you couldn't see from the surface.
> >> Certainly you can see undercutting, lack of penetration, insufficient
> >> filler and uneven ripple from the surface.
>
> >Plenty of "good looking" welds can still have internal flaws.
>

> I would have to argue with the word "plenty". If a weld is "good
> looking then it is highly likely that it will be a good weld primarily
> because in order to get a "good looking" weld you need to be a
> reasonably competent welder.
>
> Just by looking at the weld you can see whether the weld is nice and
> even with a close ripple pattern, the raised "reinforcement" portion
> of the bead is even with no bulges and hollows. You can see the heat
> lines and tell whether the parent material was badly overheated. You
> can see any undercutting. Turn the piece over and you can see whether
> penetration was 100% and whether the welder burned through and back
> welded the hole.
>
> What else do you want to check for?
>
> --
> John B.

Is this for a nuclear submarine?

[AMuzi]

-snip welds-

John B. wrote:
-snip-
> A novice? Perhaps. On the other hand he/she might very well be someone
> with a background in metal working and needed no additional knowledge
> to assemble a frame. (Note I am not talking about designing a bicycle,
> only the skills necessary to put the frame together).
-snip-

Indeed, this is a one-off by a Milwaukee machinist built for
his brother before WWII:

http://www.yellowjersey.org/aerg.html

[kolldata]

incroyable ! but what about the machine shop bills ? like you can't
ride it and not destroy it right caws its unrepairable ?

["\"T°m Sherm@n >]

On 9/14/2011 7:31 AM, John B. wrote:
> On Tue, 13 Sep 2011 13:44:12 +0000 (UTC), David Scheidt

> You were originally talking about inspecting a weld. Now you have slid
> right along to testing pressure vessels. By the way, could you post
> the testing standard that accepts testing pressure vessels for
> certification with a dye check? I ask as I've been testing pressure
> vessels for some time now and I never saw a dye check specified as a
> satisfactory test for certification.

>
>> :Ultrasonic could be used, my question was how do you record the
>> :position of the defects to allow repair.
>>
>> We've got these things called 'computers'. They do lots of
>> computations on the echos, including putting together different
>> images, and, in top end systems, can produce a much better 3-D picture
>> of the joint than an X-ray picture. (I've never heard of an Xray CT
>> machine for weld inspection, but I supose someone may have one.)
>>
>> :X-ray checking of pipe does not require access to both sides of the
>> :pipe. In fact, with really good welding crews the x-ray crew may be
>> :100 joints behind the welding crews.
>>
>> Every Xray imaging device I've ever seen or heard of uses the
>> transmission of xrays through the target, with the except of surface
>> scanning stuff (as used for peep shows at airports), which are not
>> useful for weld inspection. That requires access to both sides of the
>> thing you're X-raying: emitter on one side, detector on the other.
>

> Sorry about that but any pipe line I have worked on was tested with
> x-ray and certainly not with the source inside the pipe. I thought I
> already told you that the x-ray crews (who work at night) may be
> inspecting 100 joints from the end of the pipe.
>
> I suspect that the difference is that I've done it while you haven't.
>

Most of the testing we do of critical welds in industrial process piping
is phased array UT, not radiographic. Of course, maybe the mechanical
engineers specifying the testing do not know what they are doing (but
that is bloody unlikely).