My survivor Miata has a lot of pits in the windshield. Most of the time, it's not a problem. But occasionally the sun is low in the sky, and, well...
Is it possible to resurrect something like this? Some sort of mechanical polishing or a miracle coating?
Trent
PowerDork
2/4/24 2:22 p.m.
I attempted to use a xNet glass polishing kit on an old mini windshield that had some pretty deep scratches. The xNet system was recommended by the glass shop I use. They get great results with it when I pay them to do it for me.
I got it to about 80% of where I was hoping. It was still pretty hazy. I never got it to the point I would feel ok installing it. I was able to minimize and even remove some of the big scratches though.
Polishing glass is like polishing paint, a real skill that has to be developed. I think a lot of practice would help. I don't think I have the patience or focus for it. Within 20 minutes I'm ready to move on. My short attention span is the issue. I watch my paint guys cut and buff cars for days on end and know that could never be me, not without some sort of brain altering medication.
My E39 has some pitting that plays hell with oncoming headlights. I really don't want a non OEM windshield in that car. The rain sensing wipers don't like on BMW glass
I replaced the windshield on my E39, the wipers don't seem to have a problem with it :)
I've tried wet-sanding paint. Once it worked out okay, once it basically destroyed the paint job. That's not a good track record.
Mr_Asa
MegaDork
2/4/24 2:36 p.m.
I've heard that if you don't know what you're doing you can basically fisheye it and end up with lenses in the windshield
My next door neighbor has a company that polishes glass when it is damaged on skyscrapers. I'm sure it can be done but at what time cost?
He's told me in the past his company mostly makes sense to his customers because large commercial buildings get huge discounts on glass by buying in volume. So the replacement cost of a few panels is significantly more than what they paid for the panels originally (not to mention removal and installation labor), and fixing makes sense.
That said, I don't think he owns many huge or ultra-complex tools.
Trent
PowerDork
2/4/24 4:00 p.m.
The only 3 pics of the process that survived. I had planned on doing a tech tips post on it but since it wasn't what I'd consider successful I gave up on that idea.
The abrasive pads were a wire mesh kind of thing. Perhaps more like Abranet cloth. A random orbit polisher was the recommended tool.
My shop is still splattered with the clay polishing slurry over a year later. It was messy.
We're I someone who could imbibe cannabis, I would think it might be a nice project. Stoners make great polishers.
An older E28 guy once told me that BMW dealers used to use Brasso as glass polish back in the 70's and 80's. I tried it a couple times and it seemed to work well enough to remove light imperfections, but obviously was nowhere near the level of cut that some of these pro kits attempt.
In reply to pointofdeparture :
I have some Brasso, that might be worth a try. I don't have any major imperfections, just sandblasting.
I could get a new windshield, but the trim around this one is factory and not just a generic one smooshed into shape. That's okay for the race car. Maybe I'll see if I can source the factory trim.
My civic had a badly scratched windshield when I bought it. I tried buffing it with some maguir's paint buffing compound and a random orbital polisher. A hammer would have been more efficient.
My E46 had a lot or little scratches in the windshield when I got it. I tried a glass polishing kit, no idea what brand. The first section I worked on ended up with visible waviness so I replaced the windshield. It was probably a lack if skill and patience, but I'm not inclined to try that again.
Best polish I've found by far is the 3m glass polish. It's expensive, list is like $90/bottle. It's aggressive. And you need to be constantly misting the glass / pad with water, and you actually can overheat and crack the glass doing it... but it works damn well.
It's 3m #60150.
Being said, its easier to F up the glass than it is to get it right. For what that's worth.
Far from a miracle remedy, but a less aggressive cleaner that works remarkably well is Bon-Ami, which is a mild abrasive made from eggshells. It's not going to fix damage, but it will clean the glass quite thoroughly. I've had good results with it on older stuff where there's years of accumulation.
Eastwood has a kit that I used once because 356 windshields are rare and expensive. It's messy, time-consuming, and labor-intensive, but it works. It's also easy to polish distortions into glass if you don't evenly polish the whole windshield. Glass polish is expensive because it has a lot of rhodium. For easy to find glass, I would just call Safelite.
This is relevant to my interests. My Super Beetle's windshield becomes almost translucent at night from headlights from oncoming cars
Since most of the "thousand points of light" on the OP's windshield and most others that have been in use for a decade or two are actually small chips or pits due to impacts, I would think you'd have to remove a lot of glass to sand them out. "Polishing" per se, is going to be mostly wasted effort. I would replace the windshield, although I fully understand the OP's reluctance to do so. But I think that's your answer: Either live with it, or replace it.
Bon ami and a buffer worked well enough when I tried it that I wasn't disappointed. Full disclosure it was a $1k challenge car that I had to drive round-trip from MA so I wanted just some improvement with minimal investment...
It was messy and I definitely remember the drill brush being involved.
You might have hinted it's not a cost thing, but if it is you might have some luck with getting it done next time you're in locales that heavily gravel their roads in the winter. Here in Alberta the glass places are common that a new windshield is only $200 or so. I rarely bother filling rock chips anymore.
We use grit on the roads instead of salt, so taking a rock to the glass is pretty common. I haven't had the chance to check for the factory trim yet, but if I can find that I might just order a new windshield. I've had at least two new ones put into the race Miata, once between sessions on track :)
Rodan
UltraDork
2/7/24 5:51 p.m.
In reply to Keith Tanner :
When I built the rollcage in our NA, a new windshield cost me under $300, with installation in my garage, but that was two years ago. IIRC, I got the wiper cowl from Moss (IL Motorsport), but the Mazda one is still available at twice the price. Safelite had the rubber trim and it was included in the installation.
I've had a few Miata windshields done over the years :) Did Safelite have the Mazda trim or just some rubber trim? Because the trim used on my other replacements is okay for race car but is clearly not factory. And I'm fussy about this car for no real reason.
I have a similar but slightly different problem. I have an older Mercedes with the European headlights. They have actual stone chips in them. Not big and not many but they are there. They can not be sanded out so I have been looking for some sort of "filler" just to even them out. Maybe a clear epoxy product, a little dab to fill the hole? So far I have not found anything like that so I don't even know if such a thing exists. Honestly, you can't even see them unless you get down and look for them but mostly you have feel them to locate them. It's a little thing overall but I was wondering if anyone knows of such a thing. Thanks.
Rodan
UltraDork
2/8/24 8:35 a.m.
In reply to Keith Tanner :
Not sure if the trim on our NA is OEM, but I've not had any issues with it. The trim they used on our NB is definitely different, and I've had to go back and glue it down a couple of times.
I understand why you'd be fussy about that particular car.
Jerry
PowerDork
2/8/24 8:35 a.m.
The BRZ's windshield shows its rallycross history, but with a $100 deductible I'm tempted to have it replaced with the bullseye hit in the corner anyway.
I've tried it with a kit, and then with bulk materials. Hell of a lot of work and time, mediocre results. Managed to unlevel the glass too, so I added in wavey distortion.
I won't do it again. I'd rather replace the glass entirely.
I can still get OE trim. So that'll be the way forward if I decide to do something about the windshield. Just have to make sure it doesn't have the blue tint at the top.