The 08609 is strictly for bonding in windshields when replacing one. It's a fast, extremely strong urethane that when cured enables the windshield to become a structural part of the vehicle.

08509 is a supplemental sealer that can be used to "reseal" a leaky windshield, as well as being used as a seam sealer.

They'll both be very strong, and might be just as difficult to remove as your strip caulk was, if not harder.

 

Thanks

 

I have used both 8509 & strip caulk for what you are doing. The 8609 would not be the right product for the job. You think you had trouble removing it before...with urethane, it would be WAY worse!
Next time you have to remove it, apply some heat around the flange for a few moments & then slide a putty knife around to "cut" the seal best you can. With a bit of care, you should be able to separate them without damage. My Two Cents, Lorne

 

I used 8609 last time and it actually comes off very easy. It peels off in long strips. The dum dum I've used in the past has been a nightmare to remove. As long as the 8509 will allow me to remove the box later if needed I think that will be the right stuff for the job.