Today I finished cutting out the old battery tray and grinding it smooth. Then I took my replacement tray and started hammering it in to match the shape of the pan. Once it was as good as I could make it, I whipped out the arc welder!
I am a complete novice at arc welding. I bought a stick welder for $90 at Harbor Freight before Christmas and I have done only a few test welds with scraps of metal. Today I took the remnants of the old battery tray, cut it in half, grinded the pieces smooth, and welded them together. That turned out pretty well so I started in the car.
My practice run was not a valid indication of my proficiency. I botched the weld in the car. I did manage to tack it into place, though, so I proceeded with applying sealant around the tray. I’m sure I managed to botch that, too, but it’s air-tight and it’s not going anywhere. I lost my motivation part way through because it became evident that my entire pan has got rust problems and I will have to replace the entire thing eventually.
The tow-bar went pretty quickly as soon as I had all the parts I needed. The bolts required were no longer on the car, so I just had to track down some nuts, bolts, and washers to get it onto the car securely. Now it’s ready to be towed and to have the engine pulled! That should be tomorrow, after the EV parts arrive.