How to Polish a Lexan Windshield for Under $4

About: I have bonded with a 100% Canadian Tundra wolf. I am 6'1" and when he stands on his back legs, he can put his paws on my shoulders and we are eye to eye. He weighs more than I do, to, at 224 lbs. I love him ...


I ride a large cruiser motorcycle, and it has a Lexan brand windshield on it. I have researched online, and it turns out I can only find people who will polish and repair Acrylic windshields. They say Lexan windshields need to be replaced. Phooey to that.

A new windshield alone can run upwards of $200.

These days times are hard for all sort of people. Your 50 MPG motorcycle that costs $5 a month in insurance may just be your best bet to get around. There's no reason why you should have to drop more than $4 to get a clear, safe windshield.

A bottle of polish is under $4.

The windshield on my motorcycle is slightly yellowed from age, scratched up from the harsh desert environment where I live, *and* someone apprently had taped a sign to it at one point.

(NEVER tape a Lexan windshield, it removes the protective covering!)

I would have to look over the windshield, or around it, when I am offroad, to avoid rocks, ruts, etc. I couldn't see through it, and that is dangerous on a motorcycle.

Read on and see what I found out worked to make it clear again.

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Step 1: Removing the Windshield

First, you have to remove the windshield. It's a little hard to polish while it is still on the motorcycle.

My windshield is held onto a bracket by 4 bolts, two on each side.

Each bolt took a 12MM metric wrench. You cannot reach them with a socket, so grab an open end or box-end wrench.

Step 2: Removing the Mounting Hardware

Next, put the windshield in a safe place.

Using a phillips head screwdriver and a 10MM wrench or socket, remove the screws and acorn nuts, and the mounting hardware.

You will notice immediately how the cushion on the mounting hardware has rubbed the plastic and made permanent marks on it.

You will have to remember two things:

1. How the brackets that bolt to the mount on the motorcycle go (It is easy to reverse them).

And 2. That TWO of the screws are longer than the other. These screws go into the upper corners of the windshield where the strap brackets overlap.

If you forget, it is easy to fix. It's just easier to do it right the first time.

Step 3: Giving It a Bath

Next, you will need to give it a bath.

This will remove any bugs, dust, dirt, and the general film layer that forms over a windshield.

I used ordinary dish soap and a soft rag (Don't use anything harsh, remember, this windshield is plastic) in the bathtub with cold water. There's no reason why you can't use warm water, either.

Be sure you have a perfectly clean windshield before you begin polishing.

There's no danger of scratching the windshield with the convex portion on the bathtub if there is a cushion of water there, and treat it with care. I recommend using the shower wand instead, but I just washed each side like in the pictures.

Step 4: Let It Dry, and Get the Stuff You Need

Set the windshield on something soft and dry it gently with a soft cloth.

Go and grab your orbital sander w/ buffing wheel. It needs to vibrate and spin, I believe. What I have here is a very inexpensive battery operated orbital sander with the buffing wheel on it.

You need a vehicle clearcoat polishing compound. I am using "No. 7 Clearcoat polishing compound". There's no reason I am using this other than it was on the shelf and it was cheap, under $4.

Step 5: Apply the Compound

Next, you will want to get yourself a small, soft rag.

Place a portion of the rag over the opening of the container of the clearcoat polish, and tilt the clearcoat polish to get a SMALL amount on the rag.

Friends, it applies just like liquid car wax.

Use "Wax on Wax off, grasshopper" swirls, overlapping 50% each pass. Take a look and make sure there are no places where you may have missed a spot.

Alternatively, you do not want any big white blotches where it has been applied too thick, these are difficult to remove with the buffer (Just use your fingernail in a rag).

I purposely did not apply any compound or use the buffer on the lower bib of the windshield. I did this to demonstrate to you the difference buffing makes.

Applying the compound to both sides is recommended, however I personally used a 3-1 ration, where I polished the front 3 times for every 1 time in the rear. The front is what gets the dust, the bugs, and the film. But it doesn't hurt to do the back.

Step 6: Time to Polish!

This is the fun part.

(Set the windshield on a clean, soft, dry towel)

Make sure your buffer pad is clean and dry, and that the compound you applied is completely dry before you begin. Wet compound doesn't polish well at all. Don't ask me how I know.

You can go one of three routes, and I have tried all 3, and they all work.

1. Pressing hard. It works to get rid of compound that has pooled or is applied too thick. Not too hard mind you.

2. Pressing moderately. It works, too.

3. Pressing lightly/using just the weight of the sander. This method works well, too, but it takes longer. However, the battery lasted longer with this method. I personally prefer this method, but it won't work for moderate scratches.

Don't use a wide swath and try to get as much done as quickly as possible. Take your time. Go slow, and make sure you are really polishing the windshield properly.

For the edges, you will have to lift the windshield up and place it on your knee, perhaps, or find another method.

Something I learned: Even though the carpet is soft, there is a lot of dust in it.

Set the windshield on a clean soft towel regardless. The vibrations of the windshield edges on the carpet will actually bring dust up and on the windshield. You don't want to polish with dust, trust me!

An important thing to remember is if you are using a battery operated unit: When you hear the battery starting to lose power, STOP. Get the other battery, or let the original one charge. It will not polish well at all with even a slightly low battery. It will take longer and you will only drain the battery further.

When you are through buffing, there will be a lot of white dust static clinging to the windshield,. Wipe it off with a soft clean rag.

Step 7: The Clear Difference Between Polished and Unpolished Sections

I purposely did not polish the lower bib of the windshield. (I don't look through there, anyway.)

I washed the portion, but that is all.

Take a look at the pictures, you can clearly see how much polishing helps.

Please remember, too, that I have added no wax. What you see is what you get, the polished portions are clearer than the unpolished sections. Plus, there is still a bit of dust on the windshield, wax will clean it up.

You may have to polish it 10 times or more to get it clear again, but the result is well worth it and better than dropping $200 on a new piece of plastic.

You have to remember that my windshield was so bad I literally could not see through it a few feet ahead of me.

Step 8: Adding Some Wax for Protection

Next, we want to add a good quality wax. i am using a nanowax. It works great!

Why do this? It adds a layer of protection on the windshield and fills in any micro scratches for an even clearer windshield. I used two coats of wax. The wax coating lasts me about a week of riding.

I ride a lot off road, because I live on a dirt road (And for fun sometimes) and I repeatedly will go through dust clouds and dust storms, so my windshield is really exposed to elements that are never seen in a city.

Your wax coating may last quite a bit longer than mine.

Just wax on, let it dry, wax off, grasshopper.

Now is a good time to put a coat of wax or two on the mounting hardware!

Step 9: The Final Difference

The wax really helps. My poor windshield has been used and abused, and worst of all, taped. I can actually see through it now, which is a small miracle for me.

I think it is important to say at this point, that the lower bib portion was washed, and waxed ONLY. I did not polish it. You can see what the polishing does, and the waxing does for the main upper portion of the windshield.

The wax helps the lower bib, but when ti wears off you are hosed. Plus, it still doesn't look anywhere near as good as the main portion with the wax and the polish.

Thanks for reading.

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    17 Discussions


    10 years ago

    This is a great Instructable, but you need to add a main image of the final project to the intro step. Please do that and leave me a message when you have so that we can publish your work. Thanks!

    1 reply

    1 year ago on Step 9

    Good, common sense, easy to follow guide. One criticism... You show a can of polish in the section on waxing. Polish may have wax in it, but it also has compound. If you really want wax, buy a product that isn't labeled as polish, it's wax. Plenty of both available.


    3 years ago

    No7 is going for around 9 bucks these it has been discontinued for some odd reason....reckon they wanna stick us with those 40 dollar ''kits''; all it is is a fine abrasive with a few silicone-polymers...I made my own windshield out of a polycarbonate to fit the old brackets from JFreeman Inc they have DOT approved things sold in left over pieces that make good replacement shields.


    10 years ago on Introduction

    I work with Lexan daily, and you can't really polish it, you just make the scratches smaller. The compound fills them in, for a while. Lexan is used for it's strength to deflect debris off of the rider , Acrylic is too brittle and shatters on impact. Not good on a bike if you get hit by a chunk of tire going 55 mph.

    2 replies

    Reply 4 years ago on Introduction

    (1) You can polish Lexan. All polishing of all materials is just making the scratches smaller, whether that be steel, diamond, wood or plastic. (2) Lexan (a tradename for polycarbonate) is stronger than acrylic but the windshields of practically all light aircraft are acrylic, as well as those of many motorcycles. Acrylic is much cheaper.

    Watch out using any household detergents or any household glass cleaners as these contain ammonia and ammonia is deadly to acrylic and some other plastics. Even if immediately no damage is visible a clouding and eventually crazing is caused by ammonia.


    Reply 10 years ago on Introduction

    I hear you. But I do know that I can actually see the road better now, before when a wash and a wax didn't hardly do anything. Also, if you look, there are windshields made of acrylic, and companies who specialize in restoring them.


    4 years ago on Step 6

    Ah ha!

    Let it dry first before polishing! I simply wipe and wipe until dries.

    Will try with Turtle Polishing Compound.


    7 years ago on Introduction

    ah've installed an old dishwasher in mah shop after reading this communique!! And ah've found an assorted pack of 1000, 1500, 2000, and 2500 grit sandpaper @ a local autoparts store, although, like Tunny(sic), this is only a very last resort for the worst case. Also, sems rain-x i not a good thing to use on lexan as a wax.... the ammonia maybe?


    8 years ago on Step 4

    Toothpaste works well too....


    8 years ago on Introduction

    Only use sandpaper to remove scratches that are too deep to be removed by the Plastx. The purpose of the sandpaper is to get the surface flat, as light reflects off the scratches, which causes the glare and haze. Use the highest grit that will cut the surface to the point that the scratches don't show. I use 400 (for really rough plastic), then 600 (for light haze), then 1000 (for restoring the translucency), wet-or-dry sandpaper. When you use the sandpaper, always do 2 things. First, rub the sandpaper against itself several times before use. That will knock down the larger pieces of grit that would leave deeper scratches. Second, always wet sand! What I do is sand with water first, getting a uniformly smooth surface. You don't want any scratches showing that are deeper than others. Then using the same piece of sandpaper, I put the Plastx on the plastic and sand, using the Plastx as the lubricant instead of water. I use the old piece of sandpaper because it has all the high pieces of grit already worn off and won't add any deep scratches, like a new piece would. Then use the Plastx by itself with a polishing cloth. I hope this helps.


    9 years ago on Introduction

    Tundrawolf, Hi!

    Great job, thanks!  

    The bike I ride has a top and bottom windscreen that both are lookingrather ragged.    I'll give this a try, probably using anold handheld electric shoe polisher I have.  

    I wonder if a mixture of baking soda and something else might work as apolishing compound.   Any thoughts anyone?



    4 replies

    Reply 9 years ago on Introduction

    Hi Liz!

    Every time I use the above method it comes out looking a little better.

    Here's something you might find interesting:

    I recently tried to polish a helmet visor (Scorpion).

    I polished it many times with the No.4 polish but it was mediocreat best. So, I took some 1100 grit sandpaper and sanded the frontof it (Trust me when I say, the visor was unusable anyway, Ithought what the heck).

    I proceeded to polish it like the above method after sanding (Thesanding left the visor barely translucent) and it is coming out GREAT.But, it has taken me at least 35 separate times to polish it.

    I think if you have the motivation and time, you can make just about anyplastic clear again. It would be very interesting to see how baking soda(And water?) would polish the windshield.


    Reply 9 years ago on Introduction

    Tundrawolf, Hi!

    Thanks!   I'm going to give it a try.   Thepolishing and all might happen over the winter though.  Up here inVermont it's been snowing already.   Although I might run awayfor a couple of months when it's slow in the winter, maybe ride to thesouthwest or something where it's warmer.

    One thing I thought of when I was reading about you washing thewindscreens in the bathtub is that I've been putting mine in thedishwasher.   Yep, silly maybe, but the two pieces come outspotless.   I took the top drawer thingie, that the glasses go in,out of the dishwasher, so I had more height for the wind screens.  Does that make sense?  

    I'll try the 1100 grit too.  




    Reply 9 years ago on Introduction


    If I was you I would try the straight polish first.

    Honestly, the sandpaper method is for plastic that is so far gone...I have invested much more than $30 in my time (The cost of thevisor) to make my visor usable, and I have no doubt you will bepolishing your windshield for a few weeks to get it so you can seethrough it again after the sandpaper.

    I actually do not have $30 so it is worth it for me to have investedliterally 10 hours of polishing so far into my visor (My visor is 1/20ththe windshield, so it may take 100 hours of polishing to get mywindshield to this level of clear) to make it usable in these coldwinter days.

    Plus, the visor isn't Lexan, I cannot say how sanding Lexan andthen polishing it 50+ separate times will make the windshield come out.

    What I am trying to bring out here is that IF you use the sandpaperroute (I recommend a much finer grade, I just had 1100 at thetime) you MAY be on a MUCH more involved road to making it clearthan you are willing to endure. However, if you are snowed in for weeksat a time, by all means, go ahead!

    You could sand a teeny tiny spot on the lower windshield and see howlong it takes to make it the level of clear you want.

    However, the dishwasher idea is fantastic, because you are almostguaranteed to getting the bugs off. I almost wish I had adishwasher for this purpose. Well done! :)


    Reply 9 years ago on Introduction

    TundraWolf, Hi!

    I think I'll stick to using your method of polishing the windscreen.   It's really not that bad that I'd want to take onthe task of sanding it.    I might try polishing my faceshield too.

    Cool that you like the dishwasher idea.    Someone oncetold me a good way to get the bugs off is using hydrogenperoxide.   They said it literally eats the bug up, like itdoes when it bubbles in a dirty cut.