Greetings. I have the dreaded small gap in the hard plastic around the sunroof that is now the source of a water leak. I am researching different products to fill the gap before I just move on to a whole new glass unit. Any testimonials out there for a silicone or adhesive that you have used with success? 3M weatherstrip adhesive looks like a contender, but it was designed for metal, not glass. Thoughts?
Greetings. I have the dreaded small gap in the hard plastic around the sunroof that is now the source of a water leak. I am researching different products to fill the gap before I just move on to a whole new glass unit. Any testimonials out there for a silicone or adhesive that you have used with success? 3M weatherstrip adhesive looks like a contender, but it was designed for metal, not glass. Thoughts?
The 3M weatherstrip adhesive did not work when I tried it. It doesn't really harden and seal.
What did work - I removed the rubber seal. The hard plastic was loose on the glass for a couple of inches on each side of the gap. I gently pulled it back and cleaned it well, then used standard outdoor clear silicone caulk and pushed it into place. I then used the caulk to fill the gap all the way through the "J" that the rubber seal sits in. Finally pushed the rubber seal back into place. Its held for almost 2 years without issue.
Thanks for the response Bisho. I was thinking that a product that doesn't totally harden would be desirable in this application. I will continue to research products.
Thanks for the response Bisho. I was thinking that a product that doesn't totally harden would be desirable in this application. I will continue to research products.
My initial thought was to do just that and replace the whole unit. That's essentially been my approach with all maintenance and repair for the last 15 years. For the sunroof glass, it's not overly expensive and the job isn't really a job. That said, I think if you find the right sealant/adhesive product it could be effective for quite a while. After a bit of research I've decided on a silicone adhesive, basically gasket sealant, because of its thermo properties, UV resistance, and flexibility after curing. I happened to have some that I ordered from a water pump job. Here is a picture of what I used and the repair. Will let you know if it is effective.
If you're looking for the best solution to stop a water leak the 3M 4000 UV marine stuff is the best out there. I suppose it's not technically a silicone but this is the ticket to stop leaks. https://www.3m.com/3M/en_US/p/d/b40066991/
Can be used to waterproof boat parts that sit underwater yet remains pliable enough to remove if you ever need to. I used these for my roof rack bolts along with other projects after trial and error with many other brands.
Updating this for archival purposes to help the next guy. So far so good on the butt joint repair as shown in the photo using the toyota brand silicone gasket adhesive i had on hand. It's been through the car wash with no leaks.