Windshield area rust

[RPS99SHO]

Ever seen this before?

 

[jbtvt]

Yeah

I've fixed this issue on multiple vehicles without recurrence, for up to four years and counting at this point. First pull all the trim around the entire windshield, then scrape all loose rust using a screwdriver and run a rough sandpaper thoroughly over it. If you need to paint any areas make sure they're extra clean. Blow out the joint and treat with phosphoric acid per directions on bottle (or as a second choice, any phosphoric acid containing primer).

If you can't cover the entire affected area with caulking and need to paint, follow acid treatment with primer and paint. Let dry and then masking tape both sides of the joint all the way around the windshield and fill with Dow Corning 795 silicone sealant. This is not your typical hardware store caulk, it is professional glaziers sealant and makes all the difference - does not shrink or oxidize at all and has unsurpassed adhesion and flexibility. It's sold by industrial supply stores, or online at Amazon, not cheap, but worth it unless you want to do this every year. Finally, tool the joint with a plastic putty knife, and throw away that worthless, water-holding trim.

My windshield, before cleaning up the joints after it dries -

 

[bootown]

yeah, i had to have that fixed in my last 4runner. i talked to a guy installing my windshield one time and he told me it was because of how most installers remove the windshield. i can't remember how he did it, but i commented on how i liked how he was removing mine which then led to our conversation of installers as the cause for rust starting there. they roll on some black stuff after they hack up your paint to "prevent rust" from starting but it doesn't work

 

[RPS99SHO]

yeah, i had to have that fixed in my last 4runner. i talked to a guy installing my windshield one time and he told me it was because of how most installers remove the windshield. i can't remember how he did it, but i commented on how i liked how he was removing mine which then led to our conversation of installers as the cause for rust starting there. they roll on some black stuff after they hack up your paint to "prevent rust" from starting but it doesn't work

How did you fix it?

 

[RPS99SHO]

Yeah

Wow, that's intense. I don't know how I feel about caulking all that. Seems kinda permanent. What if the windshield needs to be replaced again in the future?

Would POR15ing underneath and replacing the weather stripping?

 

[bootown]

How did you fix it?

i'm not sure what was done. an auto body shop owed me some work so they fixed it

 

[jbtvt]

I have seen this on several cars that had original glass but good point, if the paint gets dinged it would be more likely to rust as well.

The weatherstrip is the reason this areas rot in the first place. It lets water in but prevents it from evaporating out quickly so you wind up with water, and often salt, that sits against the steel. I can see in your photo actually another cause why - it's 2 pieces of steel which would be primed at best on the inside/at the joint of the 2. Rust can start on the primed area and work around.

None of the one part rust stoppers hold up like paint would in my limited experience, they will rust through again, esp if you live in the salt belt. If you're worried about replacement you can put backer rod in the joint before you caulk which will limit adhesion area but silicone is easy to cut out either way, much more so than the adhesive that hold your glass in place. Best to ditch the weatherstrip. Do it right or do it twice, as they say.

 

[Scramble]

Ever seen this before?

I hope mine doesn't look like this when I pull the glass.

 

[Mark_BC]

I don't trust an auto glass shop to do this, they are probably the ones who caused the problem in the first place by scratching the paint. I am sure the rust on my mom's is from shoddy windshield removal and not repairing the scratches properly. The windshield is cracked so it will be covered by insurance (minus deductible), I just don't know how this would work if I am doing the repair work on the paint. Maybe I can remove it myself, repair it, then do a temporary jerry rig job to re-install the bad windshield with a few silicone dabs here and there so I can drive it into the shop for them to put the new windshield in.

 

[RAD4Runner]

I hope mine doesn't look like this when I pull the glass.

If it has metal that have rusted through, it would require some metal repair/welding. Check out Magnet18's thread on Yotatech.

... I just don't know how this would work if I am doing the repair work on the paint. Maybe I can remove it myself, repair it, then do a temporary jerry rig job to re-install the bad windshield with a few silicone dabs here and there so I can drive it into the shop for them to put the new windshield in.

There is some law about not using silicone to install windshield.

I have no rust through so... (write-up here)

(1) Glass shop, at least here in California, removed my windshield at home, and gave me time to fix the pinch-weld.

(2) I thoroughly sanded down to bare metal, treated with degreaser, metal prep, then applied POR-15 (all above part of starter kit).

(3) Glass tech came back to re-install glass, directly on primed POR-15

So far so good. I still have a leak but not at windshield interface. I traced it to brittle, cracked seam seal on gutter above passenger side window. Reason why I would not mount a roof rack on my gutter.


Definitely get rid of that windshield trim, for reason mentioned above. It is purely cosmetic.
This is how a windshield should be installed on a utilitarian vehicle, especially one that sees saltwater.

 

[k2damfc]

Mine looks just as bad. I went to a body shop and they told me I would have to have them cut a whole front section of a roof off one and weld it into mine. Around $3000 to do it. Nope!
So what I have done, and currently in the process of doing:
1. Friend came over and welded the big holes, which was hard due to how thin it is
2. Used metallic bondo to fill any deep/big holes. Sanded and need another coat
3. My next steps: POR15 the inside of the frame and outside over rust spots
4. Resand all around and primer then paint

I don’t know body work at all so first mission on this kinda stuff. I feel it would be easier to rhino line all around the windshield so I don’t have to worry about keeping the rust areas super smooth, but not sure how I would blend it with existing paint. Currently I sanded down 4” above windshield and dont mind having 2 tone look on the front.
Also the POR15 rust sealant I got says prep with metal etching solution but they don’t sell that at same place. Can I just sand it down? Can I put POR15 over bondo?

 

[pauldub]

I don't trust an auto glass shop to do this, they are probably the ones who caused the problem in the first place by scratching the paint. I am sure the rust on my mom's is from shoddy windshield removal and not repairing the scratches properly. The windshield is cracked so it will be covered by insurance (minus deductible), I just don't know how this would work if I am doing the repair work on the paint. Maybe I can remove it myself, repair it, then do a temporary jerry rig job to re-install the bad windshield with a few silicone dabs here and there so I can drive it into the shop for them to put the new windshield in.

Do not use silicone. Silicone contamination will make it nearly impossible to get anything to bond. Even new silicone will not bond to old silicone.

 

[kolelt]

Damn. How did you guys see this issue? Was it showing around the cosmetic trim or you guys just decided to check it?

 

[Ifirefight]

Mine looks just as bad. I went to a body shop and they told me I would have to have them cut a whole front section of a roof off one and weld it into mine. Around $3000 to do it. Nope!

So what I have done, and currently in the process of doing:

1. Friend came over and welded the big holes, which was hard due to how thin it is

2. Used metallic bondo to fill any deep/big holes. Sanded and need another coat

3. My next steps: POR15 the inside of the frame and outside over rust spots

4. Resand all around and primer then paint



I don’t know body work at all so first mission on this kinda stuff. I feel it would be easier to rhino line all around the windshield so I don’t have to worry about keeping the rust areas super smooth, but not sure how I would blend it with existing paint. Currently I sanded down 4” above windshield and dont mind having 2 tone look on the front.

Also the POR15 rust sealant I got says prep with metal etching solution but they don’t sell that at same place. Can I just sand it down? Can I put POR15 over bondo?

This is an older thread. Would be interested in the OP outcome. Having did autobody for 20 years and have done this exact type of repair on many different types of vehicles. Rust is like cancer, you can slow it down but once it starts it's hard to eradicate..
Best way is to cut the rusted area way out farther than you think and weld in new metal.

Prime and repaint... anything less than that is a short term fix and will not last.


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[dozerfrelich]

I cut my bad sections out and welded in fresh steel. It doesn’t have to look pretty it just has to be structurally sturdy for the windshield. When I had the windshield put back in I put silicone all the way around the window before the weather strip so when the strip was put in there was no gap in the channel for water and salt to get into.


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[k2damfc]

Yea I mean I’m just trying to make it last a little while longer. As long as I can get a new windshield in and it seals I’m good. If I knew how to weld such thin metal, or in general, I would of added more steal. The frame seems sturdy enough to hold a windshield, I was just more worried about water and such getting in.

When I went off road I would hear a knocking and noticed my whole windshield was loose. To the point I could push it up and stick my fingers out the side, that’s how I noticed it. I should of gotten it done 2years ago but the cancer did spread.

It’s been a fun process, “Shaw”, but a hard learning experience

 

[RAD4Runner]

Non-Functional Chrome Trim SUCKS!

Fortunately, I only had a tiny pinhole that was easy to patch with the excess urethane adhesive.
My solution (here) was:
1) Remove rust, clean to bare metal,
2) Treat metal using the POR-15 starter kit.
3) Applied POR-15.
4) Had Safelite install glass directly on POR-15 using SIKA urethane adhesive and associated primers.
5) No more trim. Like something that *eep did better than Toyota...

...1. Friend came over and welded the big holes...
Also the POR15 rust sealant I got says prep with metal etching solution but they don’t sell that at same place. Can I just sand it down? Can I put POR15 over bondo?

Check POR-15's website. Somewhere it is mentioned that it is best applied directly to properly treated (and textured) metal, not over body filler.

The fewer required layers there are between the windshield urethane adhesive and the metal, the less to fail. For windshield application, after your friend had patched the big holes, you may have dips and bumps. However, they should not be that deep. Therefore, on the surface where the glass will be installed the thick bead of urethane adhesive (Sika Flex) is most likely to fill the dips (I remember reading this from one of the windshield installation websites online). No need for the layer of body filler that could fail.

3/8-INCH THICK BEAD OF URETHANE ADHESIVE (SAFELITE USES SIKA BRAND)
OK to apply body filler on surface outside the mating surface.

Do not use silicone. Silicone contamination will make it nearly impossible to get anything to bond. Even new silicone will not bond to old silicone.

Agree, although there is option to apply silicone OUTSIDE the mounting surface like dozerfrelich mentions below.
Also agree, that IF there's silicone on surface and one needs to replace windshield again, he would need to very thoroughly remove the silicone. (Did that... long story on my thread).

Damn. How did you guys see this issue? Was it showing around the cosmetic trim or you guys just decided to check it?

I saw very minute bubbling of paint outside the chrome trim on mine, so I decided to check and fix it before it got worse. Behind the chrome trim it was worse....

See how much dirt it collected... Reason why I detest any trim around my windshield.

...When I had the windshield put back in I put silicone all the way around the window before the weather strip so when the strip was put in there was no gap in the channel for water and salt to get into.

You mean after you had the windshield put back, correct? You filled the gap with Dow-Corning 795?
I did that, too, but had to remove the silicone to troubleshoot a leak that turns out was not from the windshield install. I may do that again to protect the exposed POR-15 from UV.

 

[Beaumont67]

Windshield Frame repair:
a) slight surface rust can be milled out with a carbide cutter on an Electric Drill and phos treated with EXTEND, to neutral corrosion
b) if rust corrosion has gone through the sheet metal (aka hole now), the panel is best sourced from a wrecking yard and
rust free donor sheet metal installed, with a mig welder / after all the spot welds are drilled out first

More reading here:
http://www.toyota-4runner.org/3rd-gen-t4rs/205784-rust-around-windshield-anyone-ever-repaired.html

 

[nc-grayson]

I got a new windshield and my rust spots taken care of by the windshield installer. I had rust just like seen here, and it was starting to leak into my headliner.

$410 out the door for new windshield and rust repair. they ground down the rust, resealed it well, and it's been leak free almost a year now.

edit: http://www.toyota-4runner.org/3rd-g...u-do-your-3rd-gen-today-1216.html#post2570760

 

[dozerfrelich]

Fortunately, I only had a tiny pinhole that was easy to patch with the excess urethane adhesive.
My solution (here) was:
1) Remove rust, clean to bare metal,
2) Treat metal using the POR-15 starter kit.
3) Applied POR-15.
4) Had Safelite install glass directly on POR-15 using SIKA urethane adhesive and associated primers.
5) No more trim. Like something that *eep did better than Toyota...


Check POR-15's website. Somewhere it is mentioned that it is best applied directly to properly treated (and textured) metal, not over body filler.

The fewer required layers there are between the windshield urethane adhesive and the metal, the less to fail. For windshield application, after your friend had patched the big holes, you may have dips and bumps. However, they should not be that deep. Therefore, on the surface where the glass will be installed the thick bead of urethane adhesive (Sika Flex) is most likely to fill the dips (I remember reading this from one of the windshield installation websites online). No need for the layer of body filler that could fail.

3/8-INCH THICK BEAD OF URETHANE ADHESIVE (SAFELITE USES SIKA BRAND)
OK to apply body filler on surface outside the mating surface.


Agree, although there is option to apply silicone OUTSIDE the mounting surface like dozerfrelich mentions below.
Also agree, that IF there's silicone on surface and one needs to replace windshield again, he would need to very thoroughly remove the silicone. (Did that... long story on my thread).


I saw very minute bubbling of paint outside the chrome trim on mine, so I decided to check and fix it before it got worse. Behind the chrome trim it was worse....

See how much dirt it collected... Reason why I detest any trim around my windshield.

You mean after you had the windshield put back, correct? You filled the gap with Dow-Corning 795?
I did that, too, but had to remove the silicone to troubleshoot a leak that turns out was not from the windshield install. I may do that again to protect the exposed POR-15 from UV.

Yes after windshield is out in but before the weather seal. The weather seal helps push it into the small areas.


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