I use hard siver solder a lot. I'm used to it, and I have a bit of it in stock. But horses for courses.
Maybe worth investigating how soft solder might be the way to go for this application. Thin stuff is where it's qualitys shine. The low heat requirement is on your side...
You can obviously get things hot enough to braze, you'll sh-t it in.
If you can keep it flat while welding, you eliminate a lot of issues later. You know this.
To try and tig this, you will need some fancy gear/fancy skills. One can make up for the lack of the other.
A flip top lid (nod your head) welding mask will handicap you. Dosn't mean it cant be done, but you will want to re-practice what you know. If you mig lid has a sensitivity control, you should be ok. Set it a bit higher for tig (jeez, I hope thats the right way, racking my memory now)
Pluse and slope control make up a bit for the shaky hand we ge as we get on. If you get a few D-T's with a plain scratch start tig, you're sure to make a mess. You could use the tig to tack it in place, then soft solder it to seal...assuming the 500 amp monster can get down to 20 - 30 amps.
All could be fixed with soft solder, I take Mac's side here.
We all know hard solder is stronger, but there is a limit to the requirement for "strength" in home still land. Its also more expensive. All good if you need the strength, but we don't always need it. And its hotter, you don't want heat here.
Like my dad said, do you want the drilling machine, or just the hole....do you want a bubble ball, or the very best solder holding togther something that might not work?
Back to the mesh, any furthur news?