[sick472]

The flange nut approach is what I did to solve the same problem. Do yourself a favor when welding the new nut it and screw a bolt into the flange nut prior to welding it (bolt head outwards). This will keep weld splatter from getting into the threads and reeking havoc later on. Once welded in, remove the sacrificial bolt. I also like to chase the new nut with a tap in case the heat from welding warped it some. This will make the new bolt thread in nicely and not bind and gall.