Front cap, not windshield leak saga

[erstanfo]

Saga continues
I had my windshield replaced in 2015.
This winter I got a slow leak and a few drops on the dash.
I took it back to the glass company as they had a 'lifetime warranty on leaks'. Removed the rubber trip and directed hose down between plastic C-clip/U-channel onto top of windshield, no leaks.

Then directed it upward above C-clip/U-channel toward fiberglass cap, leaked and ran down the back side of the steel windshield frame (I had previously removed Winnie's plastic trim strip on the inside so I could see the black metal frame).

Basically the trim molding and C-Clip form a dam that can hold water and it can migrate between faulty seal on front cap and metal frame then down into the coach.

Next step is to clean gap, treat rust with Ospho, paint, then get Geocel Proflex or other sealer and fill between C-Clip/U-Channel and fiberglass cap. I also plan to run a bead along the cap before I re-install the rubber trim strip to glue/seal it in place. Then the 2" wide electrical tape others have recommended.

Any recommendations on sealer to try to seal the cap to the frame?
Thanks

[Ray,IN]

I would use what auto windshield installer use, urethane. I would not use anything containing silicone, they don't. Nothing else will stick to dried silicone, not even more silicone.