Butyl vs Urethane to Seal Windshield
Thread Starter
Racer
Joined: Apr 2005
Posts: 494
Likes: 0
From: Virginia
Butyl vs Urethane to Seal Windshield
Anyone use urethane to seal their windshield?
"Using butyl tape instead of urethane. Butyl tape is an inferior adhesive, only holding to 60lbs per square inch. Urethane, by contrast, holds to 600lbs per square inch."
http://www.crackedwindshield.com/2020.html
"Using butyl tape instead of urethane. Butyl tape is an inferior adhesive, only holding to 60lbs per square inch. Urethane, by contrast, holds to 600lbs per square inch."
http://www.crackedwindshield.com/2020.html
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Butyl tape was used for many years with no widespread problems.
Urethane supposedly started to be used because of the strength you mentioned and the fact that the windshield has become a "structural" member of the unibody frameless cars.
Urethane supposedly started to be used because of the strength you mentioned and the fact that the windshield has become a "structural" member of the unibody frameless cars.
Drifting
Joined: Jan 2006
Posts: 1,944
Likes: 22
From: Yooperville MI
The web site does say modern cars. The C3 window frame is deeper than modern cars and was designed for butyl tape. The installer will need to compensate for the height if he uses urethane otherwise there will be a gap between the moldings and glass.
noonie is correct, the glass on modern cars is a structural member, thus the need for better adhesion.
noonie is correct, the glass on modern cars is a structural member, thus the need for better adhesion.
Last edited by crazywelder; Sep 27, 2006 at 05:02 PM.
Melting Slicks
Joined: Jul 2000
Posts: 2,107
Likes: 14
From: Lancaster PA
I used urethane on my 73. I made very small spacer blocks out of rubber to set my height to get correct moulding fit. I glued these to the windshield frame and made sure that the urethane filled in around them to totally seal the glass. If you cut a V shaped notch in the top of the tube tip you can get the urethane to stand pretty tall. After the glass was installed I took a putty knife and applied more urethane all the way around the glass to make sure it was sealed.
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Originally Posted by FAST73
Anyone use urethane to seal their windshield?
"Using butyl tape instead of urethane. Butyl tape is an inferior adhesive, only holding to 60lbs per square inch. Urethane, by contrast, holds to 600lbs per square inch."
http://www.crackedwindshield.com/2020.html
"Using butyl tape instead of urethane. Butyl tape is an inferior adhesive, only holding to 60lbs per square inch. Urethane, by contrast, holds to 600lbs per square inch."
http://www.crackedwindshield.com/2020.html
I also used some Butyl adhesive for some of the molding - per the AIM.
The job came out real nice and there are absolutely no leaks - which I have seen when JUST butyl tape is used.
Burning Brakes
Joined: Apr 2004
Posts: 847
Likes: 0
From: Des Allemands LA
After my proud job of fixing my rust holes and prepping the windshield sealing area with ospho and rustoleum, I had the windshield installed with urathane. Guess what happened when I put my trim on? About a 1/4" gap between molding and windshield-pissed off doesn't come close to describing that feeling. And another note-that 600psi is a PITA to try and cut/remove to fix the thing properly. Like CF6873 said get your spacers and test fit before using urathane. On the bright side I dont have to worry about the windshield ever falling out!
ltlevil
ltlevil
76, butyl, c3, corvette, forum, glass, installing, instructions, seal, sealing, tape, urethane, urthane, windshield, windshields
