Does it really take 40 - 60 hrs to polish a windshield?

PepeLoco

Senior Member
My windshield is original, the frame has quite a bit of rust at the bottom. Replacing the frame and glass is on my list of things to do; when money becomes available.

Until then, I thought of polishing it. But does it really take 40 - 60 hrs? Is it really that difficult? Which is the best way/product?

I do have a deep scratch from the wiper that I am not sure I can get out, but the millions of little ones I need to get out due to the glare at night.

Thanks!
Pepe
 
It is my understanding there are no usable original factory windshields. They all went yellow and needed to be replaced as the process they used to put the glass together was not quite perfected.

How do you know it is original and how do you know it is not a well done reproduction glass from the 60/70's with a bug put on it to make it look original?

Keep in mind that you need to sand off the glass to the bottoms of the pits. I have heard that is also not really practical, but I could be wrong.
 
It is my understanding there are no usable original factory windshields. They all went yellow and needed to be replaced as the process they used to put the glass together was not quite perfected.

How do you know it is original and how do you know it is not a well done reproduction glass from the 60/70's with a bug put on it to make it look original?

Keep in mind that you need to sand off the glass to the bottoms of the pits. I have heard that is also not really practical, but I could be wrong.

good point. I really don't know if it is original I have only had the car a few years. Nonetheless, what would be the process for polishing out the scratches in the windshield and does it take that long? Also which is the better products easier products to do it?
 
For glass, it's definitely cerium oxide. Glass shops buy straight cerium oxide and mix their own to polish ground edges and remove very fine scratches. Here's a 1 lb container: LINK Years ago when I did lapidary work I used the stuff to polish stone cabs after working them with wet 3000 grit silicon carbide. Here's another link: LINK.

To keep the glass flat, avoiding a wavy surface you'll need a fairly stiff lap, preferably rawhide. Finishing can be done with a softer buff. It takes skill and generates considerable frictional heat which can easily crack old glass so the surface must be cut slowly with frequent cooling periods unless you run a completely flooded recirc. system.

If you have any thought of doing it with the windshield in your A, forget it. There will be a mess all over and, at $25 per pound plus other materials you will easily be into it $100 or more by the time you get minor scratches and wiper marks out of the glass. You will spend about 3 hours per square foot of glass if you use a motor driven lap, about 10 hrs per square foot if you decide to work it by hand. Most of that will be wait time to permit temperature stabilization if you want to reduce the heat fracture risk. Don't forget that any minor scratch along glass is a fracture plane and any heat differential from friction between front/back side over the scratch you are trying to work out will spell disaster. Just like body work, you need a good light source to watch the reflection and see if you are holding a true flat surface.

In all honesty, unless it is some irreplaceable historic piece of glass you are far better off just replacing the glass with new.

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My windshield is original, the frame has quite a bit of rust at the bottom. Replacing the frame and glass is on my list of things to do; when money becomes available.

Until then, I thought of polishing it. But does it really take 40 - 60 hrs? Is it really that difficult? Which is the best way/product?

I do have a deep scratch from the wiper that I am not sure I can get out, but the millions of little ones I need to get out due to the glare at night.

Thanks!
Pepe

Where did you get the 40-60 hour figure from ??? Wayne
 
Where did you get the 40-60 hour figure from ??? Wayne

It has been a while since I had heard that number, don't know exactly where I heard it. But using Mike's numbers, doing it by hand would probably take that long. Plus fixing all my mistakes.
 
you didn`t say if it is a plate glass windshield or a laminated safety glass. if it is an original safety glass there will be a bug in one of the lower corners. that Bug will tell you when it was made. if ti is an Original plate glass there is no markings on them.
 
I thought all Ford windshields for the "A" were safety glass. I am speaking of the windshield only of course.

Our "30 Coupe has its original - stamped windshield, clear and solid, without any problems. Love to know the story on original windshields safety vs. plate glass. I am now confused :confused:, but that is not new for me.

Thanks -

SHEC :cool:
 
The Model A came with safety glass. During testing of a prototype Model A, Chief Engineer Harold Hicks and a mechanic were involved in an accident. Almost all of their injuries were due to the plate glass windshield, so the Model A had a safety glass windshield, the first low price car to have one. Source: Wheels for the World by Douglas Brinkley.
 
I would buy a new safety glass windshield. I don't know where you live but I get mine from Vintage Glass in Ct. Todd has all the patterns and can put the markings in if requested. He ships world wide so location is no problem. I believe he has a web site but if not ads in Hemmings and Old Cars. Don't try to buff it out yourself unless it's just a small spot.
 
I would buy a new safety glass windshield. I don't know where you live but I get mine from Vintage Glass in Ct. Todd has all the patterns and can put the markings in if requested. He ships world wide so location is no problem. I believe he has a web site but if not ads in Hemmings and Old Cars. Don't try to buff it out yourself unless it's just a small spot.


Thank you, I agree.
 
The Model A came with safety glass. During testing of a prototype Model A, Chief Engineer Harold Hicks and a mechanic were involved in an accident. Almost all of their injuries were due to the plate glass windshield, so the Model A had a safety glass windshield, the first low price car to have one. Source: Wheels for the World by Douglas Brinkley.

Thank you for the background - Very interesting.

Funny how situations can rule over the "bean counters" and make a product safer for the public at large.

Be well -

SHEC :cool:
 
It is my understanding that if you can catch your finger nail in the scratch it most likely not be able to be polished out.
 
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