I would not use Bondo as polyester resin putties are not completely waterproof.
Instead, I would use a steel-filled epoxy applied immediately after roughening the surface with coarse sandpaper to remove oxides. Many years ago I Pop-riveted an aluminum patch on the aluminum head of a roof rake, also using steel-filled epoxy to reinforce the patch. The repair has held up over many winters of raking heavy snow off the roof. The aluminum had cracked after a very hard use against partially frozen snow.
Scott? It ain't but a freaking unplanned air-hole in a salvaged metal box!
I never wasted THAT much effort when I trashed another Zero-Halliburton! Just bought a new one.
This case? Goop - cookie sheet - and four self-tappers - is all it needs. Would not even waste time FINDING my pop-rivet goods. Nor bother cutting the 'loominum to size. Bigger than the hole? So f****g what?
I KNOW where the uber-durable metal-foil tape is.
This s**t can expand like unto a rons "make work" project.
Electrical enclosure. Open knock-outs. Pop a stock code-compliant filler plug -solid OR vented - in? NFW! Too damned EASY!
He cuts steel disks. TiG welds them into the holes. Grinds. Bondos flush. Sands. Paints it. Makes a production of posting on PM how clever and pretty he is.
Meanwhile? A brand-new Weigemann box is dropped on my doorstep in two days from Zoro for $25 bucks. And all I did ... was add "NK" suffix to the SKU... for "No Knockouts" ...and put the hole(s) I wanted into an already painted box!
Make this repair TOO complicated? No longer a bargain.
Frank would be ahead to just move-house and not NEED the box!
He'll sort it. No excuses. Frank ain't even NEAR Kalifornickyah!
Oh... ""ice rake"? Snow on the roof? Too old for that s**t.
Few times it actually MATTERS? Hit a timer.
$90 worth of 3 KW or 5 KW "garage heater" up in the right spot?
Slides right off on the water now UNDER it. I don't even leave the house.
Annual power cost? Too little to bother measuring. Not as if the home wasn't insulated to a fare-the-well the REST of the winter, is it?
Beside.. how better to test-load a 10 KVA MEP-803a on the cheap and predictable?
Health risk surely would be a LOT more than that pair and a run of wire & c. cost me, though.