Sealant for sunroof replacement

amx

New member
I'm in the process of replacing the entire sunroof assembly in my all-trac. The sunroof pan is sealed from the factory with a thick bead of some kind of rubberized sealant, and I'm trying to find a replacement for it. I tried Sikaflex 221, which the internet highly recommended for this application, but it was way too soft and messy to lay up a thick enough bead to fully seal against the roof. The gap between the sunroof pan flange and the roof on the Celica is huge -- like 3/8" or more all the way around.

Has anyone here replaced their sunroof, and if so, how did you seal it? Butyl tape? Polyurethane? Bathroom caulk?
 

amx

New member
Very belated update: After doing some more research I ended up going with Sikaflex 252 because it was reported to have better anti-sag properties. In reality I don't think it was significantly easier to work with, but I had some tip-cutting beta that helped us lay up a much better bead.

The key is to cut an inverted notch into the cartridge tip. The notch should point backwards toward the cartridge, which will allow it to lay down a triangular bead that compresses into a square when the part is installed. This shape is also easy to adjust to make the bead as deep as necessary. Ours was probably 3/4" tall on average, and we still ended up having to manually push the sikaflex into place to fill a couple gaps after the sunroof was bolted in. That sunroof pan gap is no joke.
 
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