Do electronics soldering skills transfer to brazing bike frames?

Jute:
I'll learn to braze (I do silver soldering of electronics all the time)

George:
Is that low temperature stuff (ie the modern replacements for leaded solder,
using an iron) or using a torch with traditional silver solder?

As you would expect by now, I don't do the expected thing simply
because everyone else does it that way. I have the usual electrical
soldering irons but rarely use them, instead preferring to use a
catalytic pencil (it literally clips into a pocket) driven by
cigarette lighter gas. It goes up to 1300 degrees and I keep it going
full blast, so one has to be quick to make the joint. But I design and
build thermionic valve (American: tube) amps, so there are no tiny
transistors, only big parts, no resistors smaller than 2W, and the
Japanese handmade Kiwame that I like for sonic reasons have wires
sticking out of them thicker than the tube rim on many everyday bikes,
never mind racing bikes.

The solder I use is 2% silver eutectic (it melts and sets at the same
temperature, so when you remove the heat, the joint is instantly set).

The process is really a sort of moderate temperature brazing, as the
solder is intended to flow between close-fitting parts, or to be
filleted around wires.

Re learning to braze - do you have a local community college who will do
courses in such things? Could well be interesting, even if you weren't
building a frame. I'd definitely want to do it on borrowed kit first.

I wasn't actually thinking of a big gas cylinder with tubes running
all over the place, which has legal requirements and transport
difficulties (I haven't owned a car since 1992, in part to force me to
cycle, in part out of principle). I have a set of nozzles which can be
operated from a gas canister that also serves as a handle. Easy to
manipulate and put down. Probably more expensive in combustibles than
the big tank, but I don't think on a one-bicycle scale that will be a
big deal. This is a tool that could (according to the Little Fish
site, a real inspiration) do real brazing

I also have a big 200W soldering iron to burn teflon coating off, and
tin, the thick Cardas multistrand TC5 I use for loudspeaker cable.
It's a great big brutal soldering iron used for nothing else. I was
just wondering if 200W is enough to heat two bike-size pipes and the
lug properly.

A joint made with the electronics type eutectic silver solder would
definitely be weaker than one that is hard-brazed with gas (another
way of distinguishing between electric iron electronic soldering and
gas brazing is as "soft soldering" v "hard soldering").

But that merely raises another question or several. Is it necessary on
a bike frame to have hard brazing (either brass or silver) or is it
overkill? Would (lower temperature, soft) silver soldering with a big
iron for heating not be good enough for bicycles? If it is such a
great idea, why doesn't anyone do it?

Further questions that might cast light on the choice: What is the
normal failure mode of a steel bicycle frame? How often do joints come
apart spontaneously?

Here's a crucial test: Does a guy who regularly brazes bike parts for
a living, someone like Andrew Muzi simply by way of example, believe
that a soft-soldered bike by an amateur would be safe? I don't
actually fancy paying for being a pioneer by landing on my face on the
tarmac...

Alternatively you could try a Dave Yates framebuilding course - I've read
good things about those, and it would be an interesting way to get a custom
frame.

I visited his site a few weeks ago. Yates has so many bookings for his
course, he's just about given up building bikes to order.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

Andre Jute wrote:

I also have a big 200W soldering iron to burn teflon coating off, and
tin, the thick Cardas multistrand TC5 I use for loudspeaker cable.
It's a great big brutal soldering iron used for nothing else. I was
just wondering if 200W is enough to heat two bike-size pipes and the
lug properly.

I doubt it. I have been unable to reliably wet 10mm (inside dia.)
loops of 10g stranded copper with a 140W iron. Copper carries heat
away much faster than steel, but that's not very much metal compared
to a frame joint. It would be more realistic to use a plumber's
torch, since that is more or less what it's for.

A joint made with the electronics type eutectic silver solder would
definitely be weaker than one that is hard-brazed with gas (another
way of distinguishing between electric iron electronic soldering and
gas brazing is as "soft soldering" v "hard soldering").

But that merely raises another question or several. Is it necessary on
a bike frame to have hard brazing (either brass or silver) or is it
overkill?

Not overkill-- brazing is strong enough but not wildly stronger than
necessary for the job. Bond strength of common brazing fillers is
higher in some cases than the yield strength of the steel being
joined, but brazed joints are generally comparable in strength to
welded joints even though they are physically larger.

Would (lower temperature, soft) silver soldering with a big
iron for heating not be good enough for bicycles? If it is such a
great idea, why doesn't anyone do it?

That won't work with readily available lugs. Because soft solder is
much weaker than brazing material (roughly 4000 to 8000 psi tensile
yield vs. 40,000 to 100,000 psi for brazing fillers), lugs would have
to have very long sockets if they were to stand a chance. To allow
soft solder to serve as filler metal for a bike frame, the tubes
themselves might also have to be larger in diameter than normal, to
provide more wetted area and proportionally lower shear stresses. In
any plausible scenario, the frame tubes would be very much stronger
than the joints (unless you built the frame from plumbing copper).

Soft solder fillet joints are probably not feasible; I doubt that they
can be made so large that they would not yield and rupture under
typical riding stresses.

Building a frame with soft solder might be a fun thing to try-- but in
the case of success, I would advise destructively testing a soft-
soldered bike frame rather than test-riding it.

Chalo

On Nov 25, 12:00*pm, Chalo wrote:
Andre Jute wrote:

I also have a big 200W soldering iron to burn teflon coating off, and
tin, the thick Cardas multistrand TC5 I use for loudspeaker cable.
It's a great big brutal soldering iron used for nothing else. I was
just wondering if 200W is enough to heat two bike-size pipes and the
lug properly.

I doubt it. *I have been unable to reliably wet 10mm (inside dia.)
loops of 10g stranded copper with a 140W iron. *Copper carries heat
away much faster than steel, but that's not very much metal compared
to a frame joint. *It would be more realistic to use a plumber's
torch, since that is more or less what it's for.

A joint made with the electronics type eutectic silver solder would
definitely be weaker than one that is hard-brazed with gas (another
way of distinguishing between electric iron electronic soldering and
gas brazing is as "soft soldering" v "hard soldering").

But that merely raises another question or several. Is it necessary on
a bike frame to have hard brazing (either brass or silver) or is it
overkill?

Not overkill-- brazing is strong enough but not wildly stronger than
necessary for the job. *Bond strength of common brazing fillers is
higher in some cases than the yield strength of the steel being
joined, but brazed joints are generally comparable in strength to
welded joints even though they are physically larger.

Would (lower temperature, soft) silver soldering with a big
iron for heating not be good enough for bicycles? If it is such a
great idea, why doesn't anyone do it?

That won't work with readily available lugs. *Because soft solder is
much weaker than brazing material (roughly 4000 to 8000 psi tensile
yield vs. 40,000 to 100,000 psi for brazing fillers), lugs would have
to have very long sockets if they were to stand a chance. *To allow
soft solder to serve as filler metal for a bike frame, the tubes
themselves might also have to be larger in diameter than normal, to
provide more wetted area and proportionally lower shear stresses. *In
any plausible scenario, the frame tubes would be very much stronger
than the joints (unless you built the frame from plumbing copper).

Soft solder fillet joints are probably not feasible; I doubt that they
can be made so large that they would not yield and rupture under
typical riding stresses.

Building a frame with soft solder might be a fun thing to try-- but in
the case of success, I would advise destructively testing a soft-
soldered bike frame rather than test-riding it.

Chalo

A really terrible idea is one that sounded brilliant while it lasted
-- fortunately not long enough to do anyone harm! On to the next.
Thanks, Chalo. -- AJ

"Andre Jute" wrote in message
...

I wasn't actually thinking of a big gas cylinder with tubes running
all over the place, which has legal requirements and transport
difficulties (I haven't owned a car since 1992, in part to force me to
cycle, in part out of principle). I have a set of nozzles which can be
operated from a gas canister that also serves as a handle. Easy to
manipulate and put down. Probably more expensive in combustibles than
the big tank, but I don't think on a one-bicycle scale that will be a
big deal. This is a tool that could (according to the Little Fish
site, a real inspiration) do real brazing

Little Fish is unfortunately down atm, but are they talking about a plain
propane or butane blowtorch (as used by plumbers), or a MAPP gas torch
(which will do proper silver soldering, but mind the fumes)? Neither will do
real IIRC brazing - brass needs it to be hotter.

The torch you have - what sort is it? Your description could fit either a
blowtorch or a mapp gas torch.

me too.
costs for aluminum tube welding equipment, estimated even after
reading the book, Jute yawl read the book ?
costs what? twice costs for a custom frame from A/F LLC.
3 frames to brake even. ugh ugh ugh.
off course there is the arteeestic plane to evolve from
but frankly itsa lotta dough, a lotta time.
start early.
break both legs.
that said, one can evolve reliable technique for solder suck as in
plumbing
but but but does not brazing involving softening the metal surface ?
one does not soften 16 ga wire, does one ?

On Tue, 25 Nov 2008 01:50:24 -0800, Andre Jute wrote:
snip
But that merely raises another question or several. Is it necessary on a
bike frame to have hard brazing (either brass or silver) or is it
overkill? Would (lower temperature, soft) silver soldering with a big
iron for heating not be good enough for bicycles? If it is such a great
idea, why doesn't anyone do it?

not a great idea. too weak.



Further questions that might cast light on the choice: What is the
normal failure mode of a steel bicycle frame? How often do joints come
apart spontaneously?

not very, but that's because they're usually brazed/soldered with higher
strength materials.

snip

bottom line, in terms of subject title, yes, the skills of heating,
wetting, and judging the meniscus transfer very well, but there is more to
frame building than that. the prep and fluxing process is much more
involved and using a gas torch, as you should, requires a reasonable
degree of practice to ensure you're not over-heating the thin tubes as
you're trying to get sufficient heat into a thicker section like a lug or
end.

many local colleges have brazing courses, usually not too expensive. sign
up for one of those, get some practice in, then you can try your own
projects. you will not be surprised to learn that many teachers of such
courses have not only done bike stuff themselves, but they are familiar
with people wanting to do so and can thus offer good advice, particularly
on things like thermal expansion and how to minimize contraction
distortion.

if you want to build a frame, you have a couple of options for holding
tubes in place prior, drilling & pinning, and jigging. big commercial
jigs are hunky and steel - and very expensive, but you can make your own
out of wood. yes, you stand a good chance of it catching fire, so keep
some water handy. the point however is that even in conflagration mode,
it will hold dimension long enough to braze the frame satisfactorily.

[do this out doors. don't splash water on the frame - the excess cooling
rate will make the metal brittle.]

jim beam wrote:

bottom line, in terms of subject title, yes, the skills of heating,
wetting, and judging the meniscus transfer very well, but there is more to
frame building than that. *

Lots more, most of which applies whether you're brazing, welding, or
bandaging a frame together with cloth and resin. It's fun-- but if it
were easy, we'd all roll our own (at least here in r.b.t).

In my observation, soft soldering is a good way to learn what flux
does and why you use it, and important concepts like relative thermal
mass, letting gravity work for you, etc. But it doesn't involve
nearly as much heat control, or more specifically not much "steering"
the filler with gradients of heat.

the prep and fluxing process is much more
involved and using a gas torch, as you should, requires a reasonable
degree of practice to ensure you're not over-heating the thin tubes as
you're trying to get sufficient heat into a thicker section like a lug or
end.

Yep.

The new toy at Austin Bike Zoo is a gas fluxer-- a bottle that sits in
one of the gas lines, adds some kind of borate chemical as the gas
bubbles through, and turns the flame green rather than blue. It also
allows good wetting and bright, clean joints on dry metal, and almost
no clean-up afterwards. I approve.

Chalo

Andre Jute wrote:

Chalo wrote:
[...]
Building a frame with soft solder might be a fun thing to try-- but in
the case of success, I would advise destructively testing a soft-
soldered bike frame rather than test-riding it.

A really terrible idea is one that sounded brilliant while it lasted
-- fortunately not long enough to do anyone harm! On to the next.


I forgot to encourage you to get a simple MAPP/air torch (like saavy
plumbers use) and some 45% silver filler and white paste flux. That
would not give you enough heat or heat control to do a bottom bracket
joint, but you could definitely teach yourself to do the occasional
custom brazeons, household repair, and maybe bijoux for your favorite
companions. If you really take to it, you could consider tooling up
for the real deal-- but if you find it not to your liking, at least
it's a cheap experiment and opportunity to learn a new trick.

Chalo

http://www.bikeschool.com/

The effects of differing bicycle frame geometry on muscle recruitment
strategies and power during a 30-second Wingate anaerobic test
by Patrick Hills-Meyer
Thesis/dissertation : Manuscript Archival Material
Language: English
Publisher: 2004.

http://www.worldcat.org/search?q=bic...&qt=first_page
http://www.worldcat.org/search?q=bic...t=results_page

enter A.com see Talbot
http://www.worldcat.org/search?q=bic...t=results_page

every wonder abt Avery?

Oral history interview with Catherine Berry Pilcher Avery, 1981
February , excerpt 01
by Avery, Catherine Berry Pilcher, 1894-1982 (Interviewee); Thornton,
Leanne (Interviewer)

Type: Downloadable audiobook; English
Publisher: Nashville, Tn. : Nashville Public Library, 2006.
OCLC: 82538817
Web Resources: digital.library.nashville.org






The effects of differing bicycle frame geometry on muscle recruitment
strategies and power during a 30-second Wingate anaerobic test
by Patrick Hills-Meyer
Thesis/dissertation : Manuscript Archival Material
Language: English
Publisher: 2004.


world cat has loads more info than when last I searched

ooops

see Talbot

http://www.amazon.com/s/ref=nb_ss_b_...icycle+fr ame

see Talbot on ILL
tell him he has a parking ticket