Of course you know the porcelain coating will have to be ground off before welding. Then weld a short bead (1-2 inches) at different areas around the circumference to prevent overheating the metal which causes the warpage.
Your welder friend should also know to turn down the amperage of the welder to match the thickness of the metal.
New Braunfels Hondo Offset
New Braunfels Bandera (Refurbished, Modified & Improved)
32 year old Char-Broil 450
1996 Blue Weber SS Performer
2003 Black Weber SS Performer
Weber 22.5 OTS converted to OTG with rotisserie & Smokenator
Weber SJS & modified stock pot Mini-WSM
STOK Island gasser