Red Green wrote:
About 18 months ago I put in a new Borg exterior steel door. A month ago or
so the flexible vinyl(?) strip on the bottom of the door that meets the
fixed plastic(?) bottom squeaks when you open and close the door. Kind of
like the sound rubbing dry fingers over a dry balloon.

I tried both spray silicone and vegetable oil and the squeak returned
shortly afterwards.

There have been no issues with the door closing, latches and locks becoming
difficult or door edge/jamb gaps so I don't believe movement is a
contributor.

Other suggestions?

No, I haven't tried WD40.

I have used saw wax to lubricate both metal and wood door
frames/thresholds with very good results.

http://www.mytoolstore.com/relton/stickkut.html

TDD