Rubber corner molding technique

[gprocket]

Does anyone wish to share their knowledge of corner molding such as what you might see in a car door weatherstrip?
Specifically I am talking about taking an EPDM extrusion and inserting it into a mold that will form the corners.

Do you prep the extrusion (ie a Chemlok or MEK emulsion)?

Do you modify the extrusion compound to run in the mold or is it a completely different compound?

How good of a bond (in a qualitative sense) can you expect?

I have a great deal of experience in rubber molding and rubber to metal bonding but I have never done nor even seen rubber to rubber bonding.

Thanks for the tips,

- Rich D.