Hi, I'm restoring a 1969 GT-500 presently I am ready to finish the undercariage . I have some questions.
First: what is the sequence about sealer, primer(red oxide) and overspray?
Noticed you mentioned red oxide - is that for the floor or for the firewall forward?
I ask since most of the year it appears that they used batch color rather than red oxide for the floors though we have identified two periods where they did use the red oxide for a while
Guess the first question should always be (since we know where it was built
when was it built?
Discussing only the undercarriage (plenty of other details can get in the way) seam sealers were applied after the floor pans were painted. Rear wheelwell sound deadener was applied before exterior color (overspray from that application can typically be seen on the inner frame, some floor or gas tank drop near by to the wheelwell) then over the overspray pinch weld black out overspray
Typically, for 69 Dearborn, we'll find the pinchweld to floor seam, inner seat belt anchor points and the trunk drop to quarterpanel weld line (on the inner surface) sealed.
Noticed you mentioned a 70 - please try and use cars from the same plant - same year - same week or month for references. Too many variables IMHO when you get off focus
Second:does the sealer along the floor pan ,around the rear frame rails are applyed with brush or with a special gun?
third:It is possible that some sealers are applyed in first and other are applyed at the end?
For seam sealers the base was typically smeared with a rag or a brush dipped in a solvent
Someone have pics about an original unrestored undercarriage please
If you provide a build date or a VIN we can post some pictures from cars from that period hopefully