The Stovebolt Site Forums The Shop Area Paint and Body Shop Windshiled leaking?

My windshield had been leaking and it had the original windshield and gasket. I replaced both the windshield and gasket. When I pulled the old windshield the the metal lip was in great shape. No rust. I cleaned it up and gave it a fresh coat of pain. I then install the new windshield and one piece gasket without incident. It went very smoothly.

2 weeks later we get rain.

It is still leaking in the same corner. As recommended I even caulked around the the gasket by lifting the gasket away from the windshield, placing the nozzle of the tube of black silicon caulk in under the gasket and running it around the entire windshield. As I moved the nozzle around the windshield and the gasket close back onto the windshield as I moved forward a small amount of silicone squeezed out indicating to me I had the proper amount of caulk in place.

I repeated this process on the part of the gasket that engaged the lip. See the two photos.

Any idea how or why the windshield is leaking?

Just a thought...was the silicon you chose specifically designed for windshields. You say the pinch weld was sound all around, huh. Of course in hindsight you probably didn't water test after 24 to 48 hrs. cure out. Interesting, I'll be dealing a windshield/gasket change out on my '59 in the near future. I don't think mine has ever been changed rubber hard as a rock. Good Luck....lets see what the experts come up with.

The silicone was for indoor/outdoor use and list it sticks to all types of material. Wood, metal, pain, glass, rubber, etc.... This is the type of silicone you use for doors and windows around the house. It did not get wet for at least 5 days after sealing it.

Perhaps the windshield divider post? Maybe it “capillaried” down the lip to the corner?

My 54 also leaks .when the window was replaced it was done by a glass outfit .It leaked in the same spot yours is he came back and put some sealant around it and it was okay for a few years but now it is leaking again. I was at the glass shop and was told that they would have to take the window out and clean all the sealant off .Said it would be cheaper to get a new seal as it should seal without the sealant.The sealant was a urathane that is used to glue newer windshields to the vehicle.

"My 54 also leaks."

If you have to get a new seal, spend the extra $$ and get it from Steele Rubber Products.
1954/55st windshield gasket - "standard"
1955/55st windshield gasket - for use with SS trim inserts

The less common gasket (for use with SS inserts) is less expensive - go figure?

Urethane is the wrong type of sealant for your windshield. It calls for a sealant type which does not become hard.
You need a new glass guy, bless his heart. He should know that these windshields do require a sealant and which kind is called for.

Yes you are correct the guy who put the window in and sealed it is no longer in the glass business.The glass shop recommended new seal due to the time it would take to clean out the wrong sealant

You said you sealed between the glass and gasket, did you seal between cab and gasket? The picture looks like the bottom corner of the glass may be a trifle small, which is not unusual. We used to work a piece of screen spline into the groove to push the gasket out. This would probably be next to impossible at this point, depending on how well the silicone on the glass stuck. Originally the sealant used was a caulk that stayed soft for a long time (most was labelled "bedding and glazing"}. Several years ago the FMVSS was amended to require urethane be used to retain any stationary glass in a rollover. This is probably why the shop mentioned used it. Unfortunately, it can be next to impossible to remove the glass and save the gasket when this is done. I haven't been involved in the glass business for 4-5 years now, but a couple weeks ago I was able to find a tube of "bedding and glazing" made by a Canadian company at my local NAPA to use on my nephews Chevy II. Any silicone used for these purposes should be automotive type containing no acetic acid (the vinegar smell) to prevent metal corrosion. Silicones were used on school bus windshield installs since they needed to be able to be kicked out in an emergency. Hopefully some of this long winded post may be helpful to someone. John

This 3M Auto Bedding & Glazing Compound looks interesting.
Has anyone used it?

- Designed for creating seal between rubber windshield gasket and auto body
- Non-hardening synthetic rubber-based formula is ideal as a glass bedding
- Suitable for use as supplementary sealer for auto glass
- Non-sagging properties are excellent for overhead and vertical auto seals

"3Mâ„¢ Auto Bedding and Glazing Compound is a flexible sealer designed specifically for creating a watertight seal between windshield rubber gaskets and auto bodies. This synthetic rubber-based sealer remains permanently soft, making it suitable as a bedding and a supplementary adhesive sealer for auto glass. It also resists sagging for use in vertical and overhead auto seals."

I used the 3M sealant listed above for my front windshield and the rear window with new seals. I had to order it at my local flaps (only took 1 day to get in)
So far (1 year later) No leaks.
My local Glass shop said that's all they use on their installations.
Todd

It was just over $20.00 at O'Reilly's.. last year.
My 12 year old helping Dad...

I've used the 3M with no problems. My only complaint is why can't I get the same stuff I used 40 years ago? And that doesn't just apply to sealants! John

this is a great company.And have many sealants for wind shields CRL wind shield sealants.non Harding. Check out their web site or the link to what you seek.
https://www.amazon.com/C-R-LAURENCE-CRL7711-Windshield-Sealant/dp/B00QL4T6M2

So whats the verdict fellows.....3M or this C-R-Laurence -CRL-7711 stuff?

For those of us gearing up to change our glass.

they also sell wet seal butyl real good stuff never dries you pump in and it seals

My research has found that 3M 08509 Auto Bedding and Glazing compound is the correct material to use. It is also what Steele Rubber supplies with their Rope-In Glass Installation kit.

They are the same products

If it's from 3M, it has to be good. (I was a facilities Distribution Analyst for 33 years...worked closely with every mode of transportation...great career).

I just spent about 3 months trying to buy a tube of the 3M 08509 from two different sources. The NAPA guy just told me it is no longer made. Does anyone know if 3M makes a replacement product? When I look at their website for windshield adhesives 08509 is still listed. Does anyone know if someone else makes a non hardening sealant?

Call 3M tech support.

Here's 08609.

Maybe it's an updated version

What is the proper way to use the sealant? Is it applied before the gasket is installed or after? Do you use it on both the metal facing side and the glass facing side or just one of them? I've got glass replacement to do and this is really helpful info! Thanks!

Tinnerjohn will have some thoughts on this, Mike. Hopefully he'll post them. They could be different from my ideas but that helps the world spin around I suppose. I've seen it done both ways but I think it may work better to seal after the glass is installed...even though the shop manual says apply the sealer first. At least I'll say when I've applied the sealer first, I've never figured out how to keep from getting it everywhere (and especially generously on me). In addition to this I have never found it easy to move the windshield around if the sealer is already on it and I don't like to worry about cracking anything or having to force things. Once the windshield is installed and adjusted, mask the body well and very close up to the rubber's edge. I normally use 2 layers of good 1 inch masking tape. You can also mask the cowl area with a couple of layers of good heavy masking paper. You can't protect things too much. Then use a ball hook tool to carefully lift up the windshield rubber, insert the tip of the caulking gun in the opening you just formed (the tip cut so as to leave a bead something like 1/4 inch...maybe a bit less) and force the sealer (I use 3M 08509...08609 is a quick-drying urethane sealer that I don't think would be as good in the AD pickup) in as you move around the windshield. It will find its way into the crack and a bit will come out on the masking tape if you're doing it right...as it fills in the gap, that is. Oh, I should have mentioned do this on a warm to slightly hot day...not on a cold day and if you'll remove your windshield wipers, tie strings around the posts, remove the nuts and molding and push the posts back inside (the strings will let you easily pull them out again) it will be easier to work your caulking gun around on the bottom. You won't have as much room there as you might wish. Usually I start at the top part of the windshield in the middle and work around to the cowl area. Then repeat the same thing for the area between the middle heading back to where you had stopped. Use mineral spirits to clean up any that got on the rubber and remove the masking tape and any masking paper you may have used. Then you can use some mineral spirits to remove any that might have gotten on the paint. For the windshield to the rubber, the last time I did this I used the urethane rubber type and cut the tip as small as possible to still get a hole in it. You may find the corners (upper corners) pucker out a bit. You can start at the pucker-gap and work around the perimeter in both directions, but don't squirt the urethane in that pucker gap yet...save that area for last because that urethane stuff (3M 08693) is a fast-setting adhesive. When you're finished tape that pucker-gap piece down quickly with good quality masking tape and leave it alone for a day or so to be sure it stays put. You can use adhesive remover to clean this type of sealer up or you can mask around your windshield very close to the rubber line to keep from getting it on the glass. Don't overapply it. You don't need a lot between the rubber and the glass. Good luck!

Jon,

Awesome write up! Thanks! One quick question. As I read your write up, the sealant is only applied on the outside of the truck. No sealant is applied on the interior side of things. Did I read that the right way?

Thanks, again!

Yes, Mike. I don't put any sealant on the interior side. I have always figured the best approach was to keep water from getting into that area with sealant on the outside. One of these days I'll do a tech tip with images on this but I need to wait until we're past the 100+ degree days. There are limits to to warm weather.

I wanted to give an update on the CRL7708 CRL Windshield and Body Sealant. After 3M told me their 08509 is no longer available (even though they still list it on their website) I bought a tube of CRL7708 on Amazon and used the whole tube on the lower third of the windshield. Since it supposedly never hardens I stuck the tip between the gasket and the glass (after masking off above and below the gasket). It was incredibly messy just as several posters had mentioned with the 3M product. Of course once I did this it didn’t rain for about a month. Finally last week we got a little rain and my windshield didn’t leak! Only time will tell if it holds up.