I cut out a section of drywall to do a repair to the exterior of my house and now need to put the piece I cut out back in. How can I do this without having a raised edge where the tape is?
Like any other drywall patch - there IS a raised area where the tape is. But you feather compound out 6-12" and there is no NOTICEABLE raised area, as the deviation from "exactly flat" is too small for the eye to see.
Tape with a 4" knife. Re-coat with an 8" knife. Finish with a 12" knife.
After the repair section has dried, apply a thin coat of mud over it.
Now get a wet sponge and pat over the wet mud. This will remove any seams and make it look like it blends in better.
Good luck! Let us know what you ultimately use that worked for you.