Auto body repair & detailing: Small body area repairs, polyester filler, zinc chromate

Question
Mr. Hall,
The driver door of my 94 T-bird LX was rusted with pinholes clear thru, about a 3" X 5" area, I ground down to bare metal a area of 10" X 12" to make sure of no spider leg rust, MIG welded new sheetmetal to area. What should I prep this area with, if anything, before I begin using filler compound? I have been told things as zinc chromate, epoxy paint, just bare metal as long as its totally clean and dry before applying, etc. etc. Also, is a one part, like Bondo glazing compound, okay to use as a final skim coat? What do you recommend?
I plan to have it completely repainted at a later date.
Thanks for your time. Harry T

Answer
Just make sure you have clean metal befor you apply your polyester filler. when you have that smooth use a two part glazing gompound to skim coat.then resand.  Use a two part self-etching primer over the bodyliller and bare steel.

               Good luck
                     Brian