Had to completely remove the sunroof glass from its metal tray to repair some major rust problems in the tray. Guess its to be expected once a seal shrinks and you get direct rain exposure on the roof, but its a little tricky repairing relatively long sections of thin gauge steel that have rusted through.
Factory "adhesive" seemed to be that really strong, two-sided tape, or else somebody was really good at laying down uniform beads of glue on the tray. If it were any other glass on the car, I'd expect it would need that really strong, black PU seal, like the windshield, as it would serve to improve the integrity of the body during an accident. But the sunroof has no such role. So, rather than deal with that messy, hard to apply automotive glass adhesive, I'm thinking that plain ol' silicone adhesive like we use for heavy tempered glass showers would be sufficient. Waterproof, very strong adhesive when cured. Holds 120# tempered glass panels in place, so why not for this?
Agree, disagree?
Sunroof Adhesive?
-
john keefe
- Level 7
- Posts: 1069
- Joined: Sat Sep 02, 2006 1:13 pm
- Location: Campbell, CA
-
DPDISXR4Ti
- Site Admin
- Posts: 14824
- Joined: Wed Jan 08, 2003 11:40 pm
- Location: New York
Re: Sunroof Adhesive?
The only problem with silicone is that the curing agent is basically vinegar, which is highly corrosive. My go-to sealant/adhesive is Loctite PL S30 Black Polyurethane Roof and Flashing Sealant, available at Home Depot for about $7 tube. It is very slow curing, so just be aware of that up front, but that's part of what makes it a superior product. I've used this on all sorts of projects, occasionally even it's intended use on the roof. Sometimes the two worlds collide - here you see Focus windows used on my shed I built in 2016. The windows are sealed and held in place just with PL S30...
- Shed-44.JPG (1.02 MiB) Viewed 1663 times
Brad
-
john keefe
- Level 7
- Posts: 1069
- Joined: Sat Sep 02, 2006 1:13 pm
- Location: Campbell, CA
Re: Sunroof Adhesive?
Ah... cool. I had minor doubts about the silicone adhering well to a painted surface, but the vinegar insight is key. I sometimes use the PL stuff in my construction projects; the downside compared to Liquid Nails, etc., is the longer curing time, and that it takes quite a while to get tacky enough to "grab" and hold components in place.
BTW, one of the corners of the tray that the seal bead tucks into (between tray and glass) was completely rusted away. Just left with a sharp edge pointing up at the seal. The tray's gauge was too small gauge to weld anything to it (at least, given the limitations of my skills). But, what I came up with was cutting a length of rebar bailing/tying wire which was almost the same diameter as the curved lip. Shaped it to the curve, and then JB Kwick Welded (steel) to the tray. Took a couple coats, but the end result was PDG, plus it has the rigidity of the wire inside the bend. Since its not a major stress point once the seals in place, and more needs to resist water/rust, it should be fine.
BTW, one of the corners of the tray that the seal bead tucks into (between tray and glass) was completely rusted away. Just left with a sharp edge pointing up at the seal. The tray's gauge was too small gauge to weld anything to it (at least, given the limitations of my skills). But, what I came up with was cutting a length of rebar bailing/tying wire which was almost the same diameter as the curved lip. Shaped it to the curve, and then JB Kwick Welded (steel) to the tray. Took a couple coats, but the end result was PDG, plus it has the rigidity of the wire inside the bend. Since its not a major stress point once the seals in place, and more needs to resist water/rust, it should be fine.