question. what is the best material/product to use to surround the edge of flat side gl*** that sits inside stainless. thanks in advance.
Be aware that gl*** setting tape can be had in several thickness. You can trim it with a razor blade after installation.
If you are referring to "gl*** setting tape", it is used to hold the gl*** in the window frame or track by the squeezing action created when you press the gl*** into the frame. Here's good info. http://www.hotrodhotline.com/md/html/installing_the_gl***.php
the frame in the photo is full frame and not as critical on thickness of tape. I'd go to a local gl*** shop and ask for 1/16 or 5/64 tape. or take your parts and have them mount them