Ok it has been a while since I installed a windshield. I picked up the 3M Butyl tape and tried to use the 3M 08643 I had on a shelf for years. It was dried up. I went to get some more and apparently they no longer make it?? They only carry a primer made for urethane windshield setting up. I asked if it could be used with the butyl tape and nobody seamed sure?? I called a buddy who has a shop and said to install without the primer on the glass as the new stuff might not set right?? My windshield pinch weld is just redone from bare metal to epoxy primer. Is it necessary to use the primer on the glass???? I am thinking there is no UV issues as it is covered with the chrome moldings and the adhesion would only be as good as the grip between the primer and the glass? I think the tape butyl would actually create a better grip to the glass??? IDEAS???? What is everybody using?