Hot Rods HELP !!!! 40 Ford Windshield Keeps Breaking

Hey guys, I have a situation on my hands. I am building a '40 Ford coupe.

When I purchased the car, the windshield was broken. I thought it was no big deal and simply added replacement of the gl*** on the long laundry list of things to fix.

A couple weeks ago, I had the gl*** replaced by a very reputable guy here in town. He was able to come to my shop and replaced the purchased gl*** with new Drake seals. Within 4-6 hours (I was at work) the gl*** on teh p***enger side of the windshield produced a very long PAIR of horizontal cracks.

Today, we removed the broken gl*** and replaced it (same 1/4" laminate) gl*** that I had made at a local gl*** shop. Gl*** was installed around 2pm. Sometime between 4 pm when I pushed the car back in the garage and 8pm when returned, the windshield had broken in nearly the same spot with the same style crack.

I checked the pinch weld with a straight edge and didn't notice any issues. I had seen broken gl*** on cars that were chopped when there is a large mismatch or bind, however, again there was nothing obvious. This car is not chopped. It was not been driven or even moved either time when the crack occurred. Clearly there is a point of stress somewhere.

Thoughts?

 

Looking at your picture above, it does look a little tight against the A pillar right where the crack is. Maybe the gl*** pattern is too tight in that spot or your car is slightly different. These things aren't exactly Lexus' if you know what I mean.

 

OK. Worth checking out. Thanks

 

It's very odd that it's cracking just setting there (except it was pushed back into the garage).

I would think that the gl*** guy would notice if the fit was too tight. It seems to me that the gl*** must be twisted and/or bent near the point of breaking when installed. I'd take the gl*** and the seal out and take a good gander at the window frame.

 

How can you tell, when the seal's there?

 

I might've found the problem.

 

I was only looking at the image, the gap between the rubber and the steel A pillar is not uniform, it is tighter exactly where the crack is. Or am I imagining that? Or the duck did it.

 

Am I seeing a dent in the A pillar right above the tape? If so, it might go deeper than the skin. Maybe the pinch flange is bent.

 

I think the Bandit's observation is a good one. Another thing to check is the center strips . Check them for sharp spots or a bend or perhaps being too tight.

 

I'm thinking that digging deeper into that car will tell you that it was wrecked at one time and possibly that piller was bent in more than one direction. Not enough to catch with the naked eye but enough to do exactly what it has done with you. Somewhat like the unchopped bad chop that you can't keep a windshield in.

 

install just the gasket. Run a paint stick inside the groove where the gl*** would sit. feel for any imperfections. Sometimes when replacing gl*** I take a grinder to the pinch weld lightly to clean up rust or make sure there is enough room. New rubber is close. Gl*** may be over cut by a 1/16 and that will cause the stress.

 

Maybe it's just me. Seems like a fairly large upper gap compared to the tighter lower gap. Of course, what was previously stated with the side and dent as well. How does the other side look?

 

Could be a bent A pillar. If the car was ever in an accident it could have body misalignment that didn't get fixed. Also check the rubber for gl*** chips in the gl*** groove and remember that this gl*** must be installed from the inside of the car. The rubber seems to indicate misalignment or bent pillar.

 

If It has cracked at the same place, there is a stress point right there. Take it all out, then inspect the hell out of it. Use a 12" steel rule to find any weird bumps or bends in the metal. And something does look squiffy by eye where the cracking is happening.

 

^This.

If that dent is putting pressure on the lip and the welded flange is just a bit off it will put undue stress on the gl***. Tempered windshield gl*** is designed to easily break outward. If the flange is bent with the peak proud out then the gl*** will more likely break that way rather than in towards the cabin.
Rubber gaskets tend to be fairly consistent all the way around.
Before the next gl*** is installed, have a couple buds hold it in situ without the gasket and look for areas that could cause a tight spot.

 

This.
And/or, make a new pattern so that you know you have clearance.

 

Might suggest taking the old broken gl*** and putting it in the opening (without gasket) to see if it lays flat on the body, or you can use a piece of cut paneling to make sure that it lays flat on the pinch weld. Make sure that the pattern is also small enough, gl*** included, not to bind on the pinch weld. The gl*** and gasket should lay flat in the opening. When you installed it did the rope bind at the point that the gl*** broke? If the pattern lays flat in the opening you have a piece of gl*** that is to big for the opening. Depending on the gasket depth, I used to use a 1/4 inch gap when I made the pattern.

 

Could always take both sides out and compare measurements from the "good" side. Cardboard template maybe?

 

It's that naughty duck.

 

Years ago my Uncle kept finding windows broken at his cottage. Turned out it actually was a bird breaking the gl***. A pileated woodpecker was landing on the window ledge and seeing its own reflection in the gl***. In order to protect its territory, it pecked at the other bird it thought it was seeing. As I recall, it took a while and several windows before they figured out why they kept breaking.

 

I am surprised after the first one broke there you didn't take a grinder and clearance the pinch weld in that area to give it some relief before putting the second one in.

 

That's what I was thinking....... but with a length of one-inch by eighth-inch bar stock and rock that around a bit or tap it with a hammer. It wouldn't hurt to also polish the gl*** a sixteenth shorter (and round the sharp edge off) so the gl*** truly floats in the gasket.

 

I agree with Alchemy, there is a dent in the A pillar above the masking tape and it even looks to have deformed the windshield opening a bit. I'd like to see a straightedge on the outside of the pillar to see how deep that is, and compare it to the other side. Doesn't take much to stress flat gl*** like that.

 

about to install gl*** in my coupe..eliminated the center divider . added 1/8 th both pieces in the center,,ill silicone it for a v-****..best of luck on your install..

 

Thanks guys. Great ideas.

I did check the pinch weld prior to the 2nd gl*** install. The straight edge showed no issues.

I will install just the gl*** and check for clearance as well as just the gasket and check for issues.

I will also dive deeper into the dent.

 

Hey Verno, like somebody else said, lay the gl*** up there and see if it matches all the way around, something is putting the gl*** in a bind. If it was hard to install in the gasket, that would be a giveaway, but if not, something is trying to bend the gl***.

 

Looking at the picture, there is a lot of new metal in the floors and the visible quarter. The A post on that side could be twisted in or out at the bottom causing a bind on the gl***. I would get some reference measurements using the other side to work from. Measure the door opening at the belt line on each side to compare.

 

What you see is sound barrier/insulation.

 

I've seen some references to tempered windshields. Is there such a thing? I thought only side and back gl*** was tempered and w/s are all laminated. True or not?