Join Date: Aug 2008
Location: Miamisburg, Oh.
This is a real mixed bag answer but here goes.....
1. I didn't see anything from surface rust but I'm on a small screen so maybe I missed it.
2. Mildly concerning but I wouldn't blink an eye at cutting that out and welding in a patch using weld-thru primer, then rust encapsulator when done.
3. If I'm seeing it right, there's rust-through on an area that you can't get a welder tip to so that's a bit concerning.
if it's only a small amount, like a finger or two and you're not running 600HP, I probably wouldn't worry about it.
More than a finger or two and I might consider cutting open an access hole from above, then cutting out the rusty part of the frame and welding in a patch like in Pic #2. I mean, access plates/holes are done all the time and then put back in place and covered up with undercoating or carpet/seats, interior, etc. No one see's it, no big deal.