Buffing scratches in plexiglass?

[Rustyiron]

I've got a plastic windshield on my tractor that has accumulated little scratches. I bought a couple of 4x8 (1/2" thick) sheets from a Govt Planet auction. It's called "Tuffak" and it says on the protective cover that it's a polycarbonate.
Not being familiar with the various plastics I thought that someone here might know.
I've heard of everything from buffing, sanding to a careful use of a heat gun.
I don't expect glass results but it's very expensive to replace. On several different machines it's part of my operator protection during mulching or mowing.
Thanks

 

[LS Tractor Owner]

I used this plastic polish on my motorcycle windshields. There was a bad scuff on one about 3-4" long, couple inches wide.... when I was done, it was almost invisible. Took a lot of time and elbow grease!
But that was far cheaper than buying a new windshield at $400

https://novuspolish.com/products/2-oz-plastic-polish-kit

 

[number two]

What about using one of those plastic headlamp cleaning products?

 

[Rustyiron]

I've wondered about that headlight stuff myself. I'm leaning towards thinking that is more for "yellowing" and light fogging from years of bugs, sand and probably not so much for scratches.

 

[Rustyiron]

Duh. I'm showing my age, this place was my first "stop" looking for advice. I just went to YouTube and...
I just need to decipher what remedies are BS and decide on who I'll listen to.
There's a guy that seems to have very similar conditions with a plastic windshield on a UTV.

 

[K5lwq]

Just for fun, I would try to wipe it down with some olive oil. I have done that trick on some plastic screens with great results. It certainly won’t hurt anything.

 

[seville009]

I had one on my skidsteer door.

Couldn’t tell it was full of scratches until I was facing the sunlight, or bright lights, and then it was almost impossible to see out of due to all of the scratches.

I was never able to get it clear. I think the only thing you can do is put some type of protective coating on beforr the scratches occur.

My fix was to replace it with real glass.

 

[Rustyiron]

The sunlight combined with a little dirty-dusty does make it impossible to see through.
I'm married to a plastic for the impact aspects during mulching or hammering rock or concrete.
The heat gun thing I'm seeing looks like the answer. Buffing required multiple passes with increasingly finer buffing compound and I'm lazy.

 

[sandman2234]

How far do you want to go in order to remove the scratches? A friend's machine shop was approached about helping solve the issue of Amtrack car windows getting scratched by limbs growing out on the side of the tracks. He built a vacumn hold-down system on which to lay the plexiglass windows, and using a CNC milling machine, took off a small amount of the surface which did away with the scratches, but created more issues of the marks of the cutting tools. The milled windows were then taken out back to a lean-to where they were polished back into clarity by the guy who was doing the experimentation. It actually worked quite well, but was too labor intensive to be viable.
I have a couple of those windows, used one to make a fold-up table that I would take to the gun range, along with the vacumn plate hold-down plate system that was built to do that job.
David from jax

 

[oosik]

Sixty years of riding motorcycles and many of those years with some form of Plexiglas windshield. I've tried most everything. Except olive oil.

My first suggestion. Meguiars Mirror Glaze. Clear plastic polish. This product is good and only relatively expensive.

Then there is the ULTIMATE product. I've used it to visually obscure even deep scratches on Plexiglas. This product provides excellent results and is quite expensive. 13 oz spray can - around $26.

Plexus - plastic cleaner, protectant and polish. It is used by the Air Force on their aircraft plexi windshields. A good friend in the AF told me about it.

From experience - I've found that you can not buff scratches out of Plexiglas. At best - you will create an obnoxious area of "haze".

 

[Panik]

Sixty years of riding motorcycles and many of those years with some form of Plexiglas windshield. I've tried most everything. Except olive oil.

My first suggestion. Meguiars Mirror Glaze. Clear plastic polish. This product is good and only relatively expensive.

Then there is the ULTIMATE product. I've used it to visually obscure even deep scratches on Plexiglas. This product provides excellent results and is quite expensive. 13 oz spray can - around $26.

Plexus - plastic cleaner, protectant and polish. It is used by the Air Force on their aircraft plexi windshields. A good friend in the AF told me about it.

From experience - I've found that you can not buff scratches out of Plexiglas. At best - you will create an obnoxious area of "haze"

OP, I'm kinda with Oosik on this one, but coming from a different background - the zoo and aquarium industry.

I know it's possible because I've seen the finished results in the re-surfacing of large polycarbonate viewing windows for animal enclosures. A big however is that it appears to take a fair bit of skill to pull it off in such a manner that you don't wind up making things worse by creating a haze in the area you are trying to repair.

My two pieces of advice would be:

1) Use a couple sheets of similar material as a test bed in order to dial in your materials and technique prior to attempting it on your tractor's windshield.

2) Work upward from the most minimally aggressive technique you have at your disposal and understand that you may have to work over the entire windshield to match finish levels.

....Also understand that there are some scratches you may never be able to fully hide/remove due to the depth of the marring and that in chasing perfection you may inadvertently make the situation worse.

 

[DaveMueller]

Acrylic and polycarbonate are great materials unless you want to see through them for a long time
They're relatively soft which makes them prone to scratches and difficult to polish. Most eyeglasses (including safety glasses) are polycarbonate, that's why they sell you anti-scratch coatings when you buy them.
A car repair shop I spoke to said for headlights, they use progressively finer emery cloth up to something ridiculous like 2000 grit. Works but it's labor intensive even for the relatively small headlights on cars.
Liquids like olive oil or WD-40 fill in the scratches which reduces the diffraction and makes them hard to see, but it's temporary.

 

[Williy]

Rustyiron check out this

https://www.youtube.com/results?search_query=removing+scratches+on++polycarbonate.

willy

 

[Panik]

Rustyiron check out this

https://www.youtube.com/results?search_query=removing+scratches+on++polycarbonate.

willy

I'll be darned.... that's pretty darned cool! I knew about using heat to renew other plastics (stadium chairs), and had casually read about flame polishing cut edges of polycarbonate but like my earlier post indicated I had always thought scratch removal was in the realm of fine abrasive compounds and buffing.

Be kinda neat to buy a digital temp adjustable heat gun and play around with which temperature and distance from the sheet were most effective.