welding 4130 TIG vs oxy-acetylene
Brice Erickson
1. is there any reason you couldn't oxy-acetylene a 4130 frame
together (lug-less non-fillet braze) instead of using a TIG , using a
Meco torch and ER70 filler rod .
2. are there any examples frames being built this way , given that
oxy-acetylene was extensively to fabricate aircraft using 4130
tubing for many years .
I can't think of any welded style (like a TIG) lightweight frames made
commercially pre mid 80s and was curious if there is a good reason
why or if it was just more convenient to use traditional bicycle
welding techniques ( that would be a lot more forgiving of a mistake
made )
thanks Brice
David Larson
Dave
.......... __o
............\<,
.........() / ()
Graeme Lomas
becomes really difficult if the tubes are extremely thin and on sub
1mm tubes almost impossible if you want to end up with a very neat
looking weld fillet.
Gas welding even when done by someone who has lots of practice and
high skill level is never as neat and controllable as a TIG weld
especially on thin sections -- some of this is caused by the oxidation
problems you get on the inside of the tube while welding which is
normally countered by inert gas purging while TIG welding frames. I
guess you could do this while gas welding but it seems like you may as
well go to TIG if you are going to go to that amount of trouble since
the weld will never be neat like a TIG weld. The other part of the
problem is that while it is reasonably easy to TIG parts of different
thickness like a down tube to a bottom bracket shell it is extremely
difficult to do the same with gas without overheating the thin tube.
Some decades ago when I was building 4130 race car chassis which were
primarily fillet bronze brazed we sometimes had situations where we
would gas weld one joint because of the assembly order but I never
managed to get one that looked perfect enough to not need tidying up
while the fillet brazes were always left as welded.
The other consideration is that the heat affected zone is always
greater with gas than TIG which may becomes a problem in thin butted
tubes.
Graeme
Brice Erickson
about the heliarc, mongoose used that on their chrome moly frames in
the 70s , I still have one from when I was kid.
anyway , oxy-acetylene torch welded 4130 ?
On Mar 13, 9:16 pm, David Larson <daveclar...@gmail.com> wrote:
> Pre mid-80's there were plenty of tig welded bikes. Many different makes of bmx frames in steel and aluminum, except as I recall it was called heli-arc welding due to the use of helium for shielding. Someone correct me if I'm wrong about the gas.
>
> Dave
> .......... __o
> ............\<,
> .........() / ()
>
Brice Erickson
level tubing where the ends are a little thicker ? or like the mantis
frame from 83 that I have that used aircraft 4130 tubing? (yes it's
fillet brazed ) .
when I was in high school, I made a recumbent tadpole trike, the shop
teacher questioned me for brazing it and I didn't have a good answer
other then that was how all the nicer road bikes where made ,the trike
was a failure but I learned a bit, HA ,the tandem from two old road
frames was a bit better but still a challenge to ride ( I was 17 and
immortal, but not so immortal to use the aluminum stoker stem I tig
welded together out of two old cast french ones )
anyway so reading the November 2009 issue of the home shop machinist,
there was an article by Kent White on "17 reasons to love your oxy-
acetylene torch" the author claimed that " welding 4130 for airplane
fuselages , motorcycle frames and bicycles is no problem with a
torch , and you only need a mild steel filler , such as ER70S6 or
maybe ER70D2. "
so that's why this question has been rumbling around in the back of my
mind for awhile , I didn't think it was just as simple as Kent White
put it the article , but at the same time wondered why couldn't or
hasn't it be used on tubing like the fillet brazed cro-mo schwinn
frames of the early 70s or the aircraft 4130 tubing used on the
earlier mtn frames .
this is really a curiosity question , this seemed the best place to
ask it .
thanks Brice
Peter Meilstrup
jon norstog
I've been sending OA-welded BMX bikes into the world of competition for about 14 years and haven't had any come back broken yet. And, yeah, by the time you're done welding up a frame it looks like it's been grilled.
jn
"Thursday"
M-gineering
I've got an old (40-s 50-s) French gaswelded frame hanging in the
workshop 2.3 kgs for the frame, so it isn't that thick
--
mvg
Marten Gerritsen
Kiel Windeweer
Netherlands
Ethan Labowitz
Department of Technology
Appalachian State University
Boone, NC
http://www.tec.appstate.edu/
Jonathan Kotula
Jonathan
wade barocsi
Bicycles have been built with Oxy-Acetylene torches for many years.
Up until 1980 or so most frames were brazed. These frames
were predominantly built using Oxy-Acetylene (and Oxy-Fuel with other
fuel gasses). Brazing is a process where a filler metal with a lower
melting point is used to join the tubes. Oxy-Acetylene can also be
used to "Gas weld" a bicycle frame. This process is rare, but has
also been used
successfully for many years. Very few people continue to make frames
with this process. In general it is more difficult than brazing, and
has relatively few
advantages over brazing. In large scale bicycle manufacturing TIG
welding has mostly replaced brazing because it is a less expensive
process to use for large
scale manufacturing. This does not in any way detract from the value
of brazed or gas welded frames. Framebuilders continue to use all of
these processes,
and each of us has our own preferences as to which process we use,
where, and why.
The Chimonas book attempts to use equipment that is inexpensive and
easily available to the first time builder. It is not in any way a
professional reference,
nor an attempt to show the best way to build a frame. That shouldn't
detract from it's value. It is a good book, but it is simplified to
the needs and budget of a
first time builder.
Wade Barocsi
CycleDesignUSA.com
Daniel J Niedziocha
i plan to build my next frame with gas welding.
i did a bunch of practice on 1-1/8 .035 tubing and also built a front
rack out of .035 tubing, with only gas welding it, no brazing.
here are some pictures:
http://www.flickr.com/photos/30562695@N04/5018716183/
http://www.flickr.com/photos/30562695@N04/5098678912/
http://www.flickr.com/photos/30562695@N04/5098678912/
dan
Arthur Marks
actual weld made by the process. -Arthur
mallard
From O-A welding on recycled, rebuilt frames I ended up brazing over the welds, especially along the shorelines for long-term durability.
Check your edges closely for tiny verticals, those are stress risers that'll lead to stress corrosion, naturalizing should take care of it, but lacking that brazing over worked well to get rid of the problem.
MIG/TIG to me are better for welding frames, much less heated area, better penetration control, on a recycled frame whatever, but on good tubing MIG/TIG seem by far more suited than O-A welding.
tom mallard
Brice Erickson
my mind for awhile .
thanks Brice
On Mar 14, 6:09 am, jon norstog <muttonmast...@gmail.com> wrote:
> Well, yes, I OA weld about half of my frames, the rest are fillet brazed and
> a few lugged. Most of what I weld is .9-.6-.9 butted or .9 straight gauge.
> Any thinner and it gets a little more tricky. I sent an article on the
> subject off to Jan Heine at Bicycle Quarterly, maybe he'll publish it.
>
> I've been sending OA-welded BMX bikes into the world of competition for
> about 14 years and haven't had any come back broken yet. And, yeah, by the
> time you're done welding up a frame it looks like it's been grilled.
>
> jn
>
> "Thursday"
>
> > wrote:
> > I believe Jon Norstog (Thursday Bicycles) is on this list and gas welds
> > most of his frames. Maybe he'll pipe up, or you can use that as a hint on
> > searching the old archives.
>
> > Peter
>
wade barocsi
Oxy-Acetylene over both TIG and MIG. This is mostly due to OFW's
durability and controllability.
I would agree that TIG is better suited to bicycle frames, especially
with today's thin wall tubing. I would select OFW over MIG in the
majority of cases on either an airframe or a bicycle. Controlling
penetration is one of OFW's strongest points. When you are MIG, or
Even TIG welding, you can't really see your penetration. OFW does
have more resulting distortion, than MIG or TIG, but the stresses in
the cooled structure are probably less.
With OFW you can very easily see exactly what is happening, and it is
fairly easy to ensure 100% penetration.
If I had to make a thin wall frame with OFW or MIG, OFW would be fine,
but MIG would be a real challenge without a fancy pulse-on-pulse or
computer controlled pulsing MIG.
OFW is old, and slow, but still an excellent process.
Wade Barocsi
Wade Patton
my first experience every with OFW was welding two 20d nails together
for ag class...I was 14 or 15. Full penetration/no gap was the goal, we
used no filler--I got the A.
then many years later a pal was building a plane in his garage--all gas
welded. That's when I went out and rented cylinders--and started
piddling with OFW again (before i my thoughts returned to bicycles). I
learned brazing later-after my thoughts returned to bicycles. While I'm
fairly comfortable with the process, I have no interest in sticking
bicycle tubing together with it. But as we've seen in this "thread," it
is feasible as a process.
WP
wade barocsi
OFW is the American Welding Society's acronym for Oxy-Fuel Welding.
The AWS likes to change their acronyms way too frequently.
TIG= GTAW
MIG=GMAW
Torch Brazing=TB
Wade
Wade Patton
metal!) at the end of a driveway last night.
"Heli-Arc
Welding"
Terminology dates ye strikers of the arc. Get ready for the pop-quiz.
wp
aka W3
