Heliarc refers to helium as that was the shielding gas at the time. It
is not readily available since it is lighter than air so is extremely
expensive. Argon is a fraction of the cost. Hydrogen is even cheaper
but the Germans found it wasn't a good substitute for helium some
years earlier.
The factory jigs are interesting in that they appear to have heat
sinks with curved grooves along where the welds are done. The welder
runs the torch along the top and melts it down into the groove where
it forms a nice weld bead so the front can be dressed down quickly.
When doing shroud repairs it is a challenge to get the weld pool to
hang nicely since there is nothing other than amperage control to stop
it ending up in a blob on the floor. The low current required to keep
the weld pool from blowing through doesn't quite complete the weld at
the back and that is where the cracking starts from. Going over the
back side afterwards eliminates the problem. Mostly.
Andy.
On 7/11/17, Bob Spidell <bspidell at comcast.net> wrote:
> Didn't they call it 'heliarc' back then?
>
>
> On 7/10/2017 5:50 PM, richard mayor wrote:
>> All the various panels that make up the shroud were TIG welded by Jensen.
>>
>> On Mon, Jul 10, 2017 at 11:23 AM, Henry Morrison <dos_gusanos at msn.com
>>
>> A gap that big should have a new piece of Aluminum gas welded back
>> in (if you can find the right guy) then the metal can be hammered
>> back in to shape. TIG weld usually are too hard and crack when
>> worked and tend to get bondo over the tops of them. I have never
>> seen any "factory applied" filler in any of the cars I have worked
>> on. I don't believe the BMC factory ever used it.
>>
>>
>> Cheers,
>>
>>
>> Henry Morrison, Albuquerque, NM
>>
>>
>
>
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