Brand new metal, it welds perfect. Like I’d put those welds up for a cert test. It’s the old metal on the thing that’s a challenge. I try to clean both sides but some areas I just can’t get too. Another example of why I wish I’d just ponied up and chem dipped this sob.
Chem dip would make it a challenge anyway. And likely find you a lot more work. Also, and this is huge,find a copper block. Use it for backing. Anywhere its thin. Thank me later.