Will .030" Fluxcore Work for Minor Rust Repair?

[Dan in Pasadena]

Hi guys,
If you've been following my main thread you know I'm getting ready to install door weather stripping but encountered a few very small holes: 1/8" to 1/4" on my door bottoms I need to repair first.

Yes, I KNOW .023 with "MIG Gas" (ArCo2) would be best.

I fully intend to do that in the future but I have no bottle (yet) with my Hobart Handler 140 so it will cost $189 to buy/fill the first time. I'd like to get away cheaper IF I can make it work for these tiny holes. Yes, I know to use the lowest possible heat setting and a series of tiny tack welds. I know to use a copper backer (Harbor Freight cheapo or flattened copper pipe) Can this .030" wire work?