septic wrote:
Have a question re 'firing' the [real] welder prop; there's no actual trigger, right? Would the flame have been activated from the off-screen tig control unit? Excuse my ignorance for all things welding-related.
Depends how fancy their equipment was. Some of the cheaper TIG welders (or 'Stick" machines being used to TIG) you need to 'scratch start'. The torch has a small stick of tungsten running from the cap through the center of the nozzle and sticking out a bit. You 'fire' it by turning the machine on and then giving it a little scrape against the base metal and back off. The arc then fires and is maintained. Some machines refined that into a "lift start" where you don't need to scratch it anymore and can simply touch it and lift up a bit.
Some of the more feature rich machines can fire without first making contact. You just need to get close enough for the electrical arc to jump. The torch can be turned on via a 'remote' wired to the machine. The 2 most popular remotes are foot pedals (just like a sewing machine, stomp it to run fast and run hot, just ease on it a bit to keep the amperage nice and low) or a fingertip control that is usually a slider or a wheel that is strapped to the torch handle on the business end. Those kind of remotes are best as it not only 'turns on' the torch, but also allows you a great amount of control over your heat on the fly without having to stop what you are doing and adjusting your amperage at the machine itself.
For the purposes of the film, they could easily have scratch started them, but they are hollywood big shots, they could have had remotes too. Hard to say.
Which reminds me, I do believe they did have the torches hooked up 'live' in the cutting scenes. Notice how you never see the bottom (where the cables would be hanging from the handle) in those scenes. Also I noticed this pic the other day. His nozzle and back cap are backward!
Attachment:
'stunt' welder.jpg [ 211.82 KiB | Viewed 4018 times ]
The finger grooves indicate the "front" facing welding, but the back cap is facing forward. 2 possible explanations:
-1. It was a 'stunt' welder. Someone didnt notice when they molded it and all the stunt welders are jacked up.
-2. They removed the caps and nozzles to slide the assembly out the bottom. When they needed a live one, they ran a full torch up in the body and when they needed it hang from a belt, they ran the 'bare bones' in the assembly. In this case they ran their bare bones backwards by mistake in this scene.
just theories but I like the idea of #2. With the way the cables attach to the handle (not made for quick disconnects), it would make sense.