getting ready to tig roughly a 6 X 6 inch piece on the front quarter panel down close to the door on my 1968 f100, my question is this... after this is tig welded in place i will have no access to back side of this new piece to treat, how do i handle this? do i treat back side with weldable primer before tigging on the piece?
thanks dave

new to body work, thanks for the patients