3M Ribbon Butyl Tape: what size is best?

[jimynick]

The square 3/8 would, I think, compress less percentage-wise than the round. I'd hedge my bets by measuring the thickness of the glass versus the depth of the glass channel and use the one that'd perform best to match my depths. It's a little fiddley, but time well spent. Just my 

[ToxicWolf]

The square 3/8 would, I think, compress less percentage-wise than the round. I'd hedge my bets by measuring the thickness of the glass versus the depth of the glass channel and use the one that'd perform best to match my depths. It's a little fiddley, but time well spent. Just my 

Thanks Jimynick.  I'll take measurements tomorrow.

[73EStroker]

We used out of the tube poly on my rear window with some small pieces of rubber as depth stops. Been through some nasty rain storms and no leaks yet. Glass shop did front so don't know what method they used. We also used that applicator and black primer out of the small bottle.