Rick C Johnson
A process as described below would be an exceptionally delicate and
potentially incredibly dangerous one. Certainly not to be tried at home.
While I have not attempted anything like that I have repaired a great
many crash damaged motorcycles. The details of the motorcycles aluminum
material and construction techniques vary greatly from those employed in
a bicycle. In this case I would consider only repair methods developed
for the specific frame type and material you have.
For those who appreciate cautionary tales I'll share a lesson about
pressuring aluminum vessels. Many years ago while working my first job
in motorsports I fabricated a small aluminum overflow catch tank.
Because the tank was going to be used in a fuel system I wanted to be
sure it was leak free and I rigged it up to pressurize it with air.
However, our shop had two air lines, one regulated to which I had
adjusted to my test pressure (15psi) and the other unregulated (up to
150psi). Both air hoses were the same color. I was not careful enough
and grabbed the wrong one.
Fortunately I have quick reactions and disconnected the air supply
immediately. In about one second that little tank had swelled alarmingly
and was about to explode - no doubt in my mind with great violence. I
had narrowly averted possibly significant bodily injury. The welds on
the tank were uniformly cracked from the stress of the tanks distortion
and required complete rewelding to restore their integrity.
Keep in mind that happened with simple compressed air which is commonly
about 100psi. Inert gases are stored in tanks at thousands of psi. I
shudder to think of the consequences of someone making a mistake with
regulating the pressure with one of those.
Rick
Doug Sproston wrote:
>Some motorbikes have aluminum frames, and I hear one fix is similar to what Mr Houghton mentioned, using pressure in the frame, but rather than high pressure fluid, inert gas (argon or co2) is pumped into the frame, essentially making the frame itself an air tank and then using a fuel-oxygen torch to heat the dent, when the material is hot and pliable the internal pressure pushes the dent out... Of course I have never seen it done...just read about it.
>
>As far as being safe to ride, I'd try and get it to someone who builds alum frames, he could tell you more about what damage is catastrophic and what is cosmetic...
>
>Good luck...
>
>Doug
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