Auto body repair & detailing: Mustang Floor Replacement., rust paint, resonable prices

Question
1969 Mustang needs floor panels. The panel are resonable prices. My question, do you cut back the rust to good metal and weld seam or , cut back rust and put new panel up from the bottom and weld.  Also can I braze in the floors.  

How do you stop rust, if some areas are just starting. Rust paint?  How do you finish after putting in new floor panel.  metal primer / paint/ undercoating.?  

Answer
The proper way is to cut out rust and leave about a quarter of an inch where the new panels sit.The new panel goes on top. You can braze them in but it will take a lot of work. The area must be very clean and free of rust.I recommend mig welding them in.Then caulk the seams let it dry and seal with non sandable sealer Then undercoat. if you want to paint it go ahead.
  Hope this helps

     Brian