Sometimes, joints in bike frame are brazed when the joint is correctly designed for brazing, which requires substantial overlap of the pieces being joined.
Here's why a non-fusion process won't work for a bike frame. Several of the joints in a frame are butt joints in tension (forces work to pull them apart). If you glue them together (which is what a metal-filled epoxy does) the glue does not have sufficient attachment to the metal parts of the joint.
When the joint fails, one of the metal parts parts participating in the joint will just slide out of the JB Weld, leaving both intact but quite disconnected.
On Fri, 4 Jul 2008 22:53:09 -0700 (PDT), Mullin9
<ddavidmul...@inbox.com> wrote: >I.m thinking about building a bike frame, without the use of welding >equipment. >Will "JB Weld" work for my bike frame? >Is it really as strong and shock resistant, as a weld done by the tig >welder.? >l like to know?
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On Jul 5, 10:28 am, Tom Kendrick <tkend...@yahoo.com> wrote:
> <ddavidmul...@inbox.com> wrote: > >I.m thinking about building a bike frame, without the use of welding > >equipment. > >Will "JB Weld" work for my bike frame? > >Is it really as strong and shock resistant, as a weld done by the tig > >welder.?
JB lists its strength at 3960 PSI, which is a little stronger than the best values for wood but less than bamboo. So it should be OK for a spruce, yellow pine or oak bicycle frame but inadequate a frame made of high-performance bamboo tubing.
There are all types of epoxy type substances in addition to JB Weld. They are designed for specific purposes. This is possible with the substance designed for this application. Built up a shaft two years ago where the bearing had chewed into the shaft. Machined like metal, has worked like a new shaft since. Not cheap, $100.00 for a pound. Cheaper than a $1000.00 shaft. Rick
Jim Wilkins <KB1...@gmail.com> wrote: > On Jul 5, 10:28=A0am, Tom Kendrick <tkend...@yahoo.com> wrote: > > <ddavidmul...@inbox.com> wrote: > > >I.m thinking about building a bike frame, without the use of welding > > >equipment. > > >Will "JB Weld" work for my bike frame? > > >Is it really as strong and shock resistant, as a weld done by the tig > > >welder.?
> JB lists its strength at 3960 PSI, which is a little stronger than the > best values for wood but less than bamboo. So it should be OK for a > spruce, yellow pine or oak bicycle frame but inadequate a frame made > of high-performance bamboo tubing.
For reference, chromoly 4130 steel sometimes used for bikes has a tensile strength around 60,000 psi. The weakest mild steels I think run in the 30,000 psi range.
J-B Weld is not meant for high stress applications like holding together bike frames.
Tom Kendrick wrote: > Generally speaking, NO, it won't work.
> Sometimes, joints in bike frame are brazed when the joint is correctly > designed for brazing, which requires substantial overlap of the pieces > being joined.
> Here's why a non-fusion process won't work for a bike frame. Several > of the joints in a frame are butt joints in tension (forces work to > pull them apart). If you glue them together (which is what a > metal-filled epoxy does) the glue does not have sufficient attachment > to the metal parts of the joint.
That completely ignores the numerous bike makers that produce high quality lugless frames using fillet brazing such as http://www.sheldonbrown.com/schwinn-braze.html and see bottom of page here http://www.argoscycles.com/custom-frames.htm . Regarding this post while I think the OP is a troll various frames have been bonded such as Graptec? with carbon fibre frame tubes bonded into cast aluminium lugs, I have also read that some modern frames using Reynolds tubing maybe bonded rather than brazed or silver soldered to preserve the material properties although Reynolds now produce air hardening alloy tube sets which can be welded.
> When the joint fails, one of the metal parts parts participating in > the joint will just slide out of the JB Weld, leaving both intact but > quite disconnected.
>> I.m thinking about building a bike frame, without the use of welding >> equipment. >> Will "JB Weld" work for my bike frame? >> Is it really as strong and shock resistant, as a weld done by the tig >> welder.? >> l like to know?
> ---- Posted via Pronews.com - Premium Corporate Usenet News Provider ---- > http://www.pronews.com offers corporate packages that have access to 100,000+ newsgroups
<ddavidmul...@inbox.com> wrote: >I.m thinking about building a bike frame, without the use of welding >equipment. >Will "JB Weld" work for my bike frame? >Is it really as strong and shock resistant, as a weld done by the tig >welder.? >l like to know?
Tom Kendrick wrote: > Generally speaking, NO, it won't work.
> Sometimes, joints in bike frame are brazed when the joint is correctly > designed for brazing, which requires substantial overlap of the pieces > being joined.
> Here's why a non-fusion process won't work for a bike frame. Several > of the joints in a frame are butt joints in tension (forces work to > pull them apart). If you glue them together (which is what a > metal-filled epoxy does) the glue does not have sufficient attachment > to the metal parts of the joint.
> When the joint fails, one of the metal parts parts participating in > the joint will just slide out of the JB Weld, leaving both intact but > quite disconnected.
I ride, daily, a bike that was made back in the 1970's using an epoxy bonding process, instead, of TIG welding, brazing, or silver soldering. Tubing lugs, similar to the lugs used for brazing, or silver soldering, were used for all the tubing joints. The epoxy was used in place of the brazing/soldering. I do not know about the use of JB Weld, but other expoxies have been used in the past, as, evidenced by what I ride.
I do agree that fabricating the frame without the use of lugs would cause the joints to fail when bonded together with epoxy.
I used TIG, though, to make accessories for the bike, but not while connected to the epoxy bonded frame.
> Tom Kendrick wrote: > > Generally speaking, NO, it won't work.
> > Sometimes, joints in bike frame are brazed when the joint is correctly > > designed for brazing, which requires substantial overlap of the pieces > > being joined.
> > Here's why a non-fusion process won't work for a bike frame. Several > > of the joints in a frame are butt joints in tension (forces work to > > pull them apart). If you glue them together (which is what a > > metal-filled epoxy does) the glue does not have sufficient attachment > > to the metal parts of the joint.
> > When the joint fails, one of the metal parts parts participating in > > the joint will just slide out of the JB Weld, leaving both intact but > > quite disconnected.
> I ride, daily, a bike that was made back in the 1970's using an epoxy > bonding process, instead, of TIG welding, brazing, or silver soldering. > Tubing lugs, similar to the lugs used for brazing, or silver soldering, > were used for all the tubing joints. The epoxy was used in place of the > brazing/soldering. > I do not know about the use of JB Weld, but other expoxies have been > used in the past, as, evidenced by what I ride.
> I do agree that fabricating the frame without the use of lugs would > cause the joints to fail when bonded together with epoxy.
> I used TIG, though, to make accessories for the bike, but not while > connected to the epoxy bonded frame.- Hide quoted text -
> - Show quoted text -
i think the aerospace program has shown that anaerobic adhesives can work well when properly applied. as has several brands of bike frames, particularly in the original aluminum days. of course, in those days, we also saw what can happen when anaerobic adhesives weren't properly applied. what was the name of that brand again?
