Urethane adhesive to fix leaking windshield

Joined
Mar 1, 2012
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I posted this question before at https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5380099. Trav and others suggested using flowable silicone. I used as mentioned in some of the YouTube videos. It worked for a couple of months. Last week, I got the car washed and noticed water on the EZ pass transponder. So instead of trying to fix it myself, I took it to the mechanic. He doesn't do windshield work and directed me to a local auto glass place. As I was expecting, they tell me its not worth fixing it and they would replace a windshield for ~$600 (glass+labor, including cleaning the leak area. They suspect its rusted at the leak point, by the bubbles on the top of the roof). TBH, I do not want to spend that money at the moment, so I am going to see if I can use anything else. A little bit of googling tells me that silicone can expand and contract depending on the temps so I wonder if it makes sense to use Urethane sealant? If it does, can I use https://www.amazon.com/Aleenes-Liquid-Urethane-Adhesive-4-Ounce/dp/B00KD6YW46 If at all it doesn't work, and I can at least get through 'virus-related job-on-the-line' time period, I know, I am going to replace the windshield. Thanks in advance.
 
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Joined
Nov 25, 2011
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Seattle, WA
Use Dow U-428Plus with a hand calk gun. This is the ONLY way you will seal it permanently. It's the urethane that is used to install your windshield. Yes, it's a large tube, but it's only ~$13 on amazon. It's also very messy, so be prepared with gloves. It comes off with acetone if you need to take off "oopsies". One trick is to heat it in a big pot of almost boiling water for a few minutes to get the tube warm and flowing better. Dow U-428 Plus
 

JTK

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Aug 14, 2003
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Buffalo, NY
My Ram 2017 Ram 1500 had the rear glass replaced very poorly at some point before I bought the truck used. The rear glass leaked water badly. My glass guy had to remove it and re-install it. He initially tried applying a bead to the inside of the glass, but that didn't work and it all had to come off. I didn't think to ask him what he though the previous "installer" used in terms of sealant, but I think the guy I use, uses a 3M product.
 
Joined
Aug 23, 2010
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pa
Betaseal U-418 quick cure primerless to auto glass urethane adhesive was used to set an aftermarket sliding rear glass in my truck, but i would try 100% silicone thats 100% get clear, sets in about 10 min. clean as good as possible before + since its a beater you can leave a bead exposed. read how to use it on line, good luck! i caulked 1/4" spaces required between composite flooring years ago, still no leaks!!
 
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Aug 22, 2009
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Pittsburgh,PA U.S.A.
Years ago I went to the local NAPA and asked them for something for a windshield leak. They recommended a fairly thin black rubber type glue / sealant that came in a decent size squeeze tube. It is a little messy to work with so you have to be slow and neat with using it. It sealed the leak in my cars front window, and I drove it for many years after that and it never leaked. I used it on a few things for a few years, and a neighbor had a pair of cheep shoes she liked but the sole was falling off, and I used up the remainder of it to fix her shoes. You might check your local NAPA to see if they still offer it.
 
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Nov 20, 2006
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Originally Posted by spavel6
Use Dow U-428Plus with a hand calk gun. This is the ONLY way you will seal it permanently.
Do not make blanket statements like that are blatantly false.There is vary rarely just an "only" way or only product that can do the job. The trick is to get it in the area of the crack/split in the original install material, it will flow into the damage and seal it. The thicker stuff sits on top of the damage and tries to make a new seal.
 
Joined
Jan 2, 2004
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Location
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The best way to fix it to find a competent glass guy who can take care of the rusted pinchweld. For now, flowable silicone is probably a good band-aid. Was the windshield ever replaced with non-OEM? I've seen rusted pinchwelds cause this, and its almost always careless or rookie installers who cause this. Dow, Sika, Dinitrol and 3M are very adamant about using their urethane systems as a whole and mandate if ANY metal is scratched, their black primers for metal prep is to be used ASAP to prevent rust. All of them prescribe repair and epoxy primer(like PPG DP40LF) if the pinchweld is too rusty beyond sanding to reveal fresh metal/
 
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