Polishing windscreen scratches

[Persistant]

Ok, has anyone had any success in removing substantial scratches from a windscreen?  My original one received some light to medium scratches during my crash last summer and I had hoped in saving it as my used replacement has cracks around several screw holes.

[Pat Conlon]

Polishing? Did someone say the magic word? Heh heh

Yep, I did my screen. One word: Novus

Started with 2000 grit wet sanding, even, smooth, light sanding, then on to the Novus products.

All by hand. Slowly. No power buffing to cause ripples. Slowly, ever so slowly. Patience is a virtue.

[ribbert]

Ok, has anyone had any success in removing substantial scratches from a windscreen?  My original one received some light to medium scratches during my crash last summer and I had hoped in saving it as my used replacement has cracks around several screw holes.

You are probably stuck with the really deep ones but you can soften their appearance and if the rest of the screen is glass like you tend not to notice them anyway.

There is no one step process for this. To get rid of scratches you have to remove plastic from the surface and that requires aggressive abrasion.

I have brought two back to life and it is a job best done if not in a hurry. I would work on mine until I got the shits, then let it rest for a few days then have another crack at it and so on. The end result is stunning though.

In a nutshell, I treated it like paint. I used the same process and the same products you would use to bring paint up to a glossy finish.

A couple of grades of wet and dry paper then worked my way up through cutting then polishing compounds using a 6" lambswool buff on a drill. You will never do this by hand.

I specifically did not use special plastic restoration products as they are very expensive and I could not get the enough stages of abrasion.

I used all normal automotive paint products, all of which I found in my cupboard.

I think I used 2 grades of paper and 4 grades of compound. You can't make too big a step with the abrasiveness or you will not remove the scratches from the previous one.

I have a proper buff but it is too big and unwieldy. I opted for the 6" lambswool on the drill because it suited the curvature of the screen better and could be operated with one hand while bracing it against my body with the other.

I once heard of a guy who in the latter stages of polishing got a bit careless (got the shits I believe) and flicked the screen halfway across his garage when the buff caught the edge, inflicting a whole new lot of scratches that then needed to be removed.

I used a pillow to rest the screen over while machine polishing which sort of held it.

The success of this rests largely on having a feel and an eye for what you are doing and is a bit of a trial and error job.

I remove my screen annually and buff it with the compounds and polishes. It is amazing how that fine haze scratching sneaks up on you.

I have those original finned, square top screens which can't be replaced so I had no choice.

If I had an after market screen or one for which there were replacements I would not even consider bringing one back from the severe scratching, it is more work than it's worth, screens are cheap.

Good luck

Noel

[ribbert]

Polishing? Did someone say the magic word? Heh heh

Pat, I don't believe anything on your bike ever needed serious revival!

[movenon]

I started doing mine by hand then switched over to a buffer with a foam pad. All I can say is use the buffer and a foam pad !!!
My pad is a Meguiar's "Soft Buff" W-9000 finishing pad. My screen was given to me because it was all scratched up. No deep gouges but scratched. It took a while but it looks pretty good now. I use Meguiars "PlastX" clear plastic cleaner & polish. For deeper scratches I would go with a more abrasive plastic polish to start with and finish with the PlastX. Doing it by hand is about like kissing your sister, nice thing to do but not very productive. 
Hope it helps. 
George

[Pat Conlon]

I specifically did not use special plastic restoration products as they are very expensive and I could not get the enough stages of abrasion.

Dunno about prices down under, but you can get a nice starter kit here in the US for $17:
http://www.amazon.com/Novus-Polish-Plastic-Scratch-Remover/dp/B000J41VDM

+1 about needing to progressively wet sand the medium scratches.

[X-Ray]

Doing it by hand is about like kissing your sister, nice thing to do but not very productive. 
Hope it helps. 
George

I will have to do my screen as well. But George, that comment was a pearler. I laughed so much I think a bit of wee came out, lol!!!!!!!

[fj1289]

Doing it by hand is about like kissing your sister, nice thing to do but not very productive. 
Hope it helps. 
George

I will have to do my screen as well. But George, that comment was a pearler. I laughed so much I think a bit of wee came out, lol!!!!!!!

Then you must not have been talking about a STEP- sister!!!

[cyclenutk75]

Persistant, what year is your FJ?  I've got a decent stock screen from an 89-90. Not sure if it would fit any of the later models, but sure it won't fit any of the earlier ones.
GT

[Persistant]

Persistant, what year is your FJ?  I've got a decent stock screen from an 89-90. Not sure if it would fit any of the later models, but sure it won't fit any of the earlier ones.
GT

Mine is a 93.

[Persistant]

Hi GT,

I checked Partzilla for both your year and mine and only a 91,92, or 93 will fit mine according to their cross reference for what bikes the part will fit.  Thanks for the offer though!

Andrew

[ribbert]

Dunno about prices down under, but you can get a nice starter kit here in the US for $17:
http://www.amazon.com/Novus-Polish-Plastic-Scratch-Remover/dp/B000J41VDM

+1 about needing to progressively wet sand the medium scratches.

Pat, looking at you bike I think we are on a different page here. I'm talking about scratches that cause drag and effect your fuel economy!

I can't in my wildest imagination see your bike (or probably anything you own) ever being in poor shape.

I'll bet you dust the lids of the paint tins on the top shelf in your garage.

I have one of those Novus kits but only used it once. For the sort of job I'm talking it's not even in the same league, and the bottles are too small.

I found a straight cutting compound on a buff a good first step after the wet rub.

IMO hand rubbing is more likely to result in scalloping than machine polishing. It does on paint, if you don't use a block.

But hey, who could argue technique when a bike looks like yours.

Noel

[Pat Conlon]

Thanks for the kind words Noel but...you should really see my garage...it appears that I have a hoarding disorder.
Remember, I've had my bike for 29 years now, and over the years, she has been down a couple of times so I've had some practice at repairs. I am now on my 2nd windscreen and I have a third oem windscreen tucked away in storage.

What I have learned in working scratches out of soft materials and dealing with the compound curve of the '84's windscreen is that.....
Giving 'me' a power buffer with a cutting compound is like giving a monkey a machine gun...

Power buffing for final polish is fine... I can do that.... although not for scratches.
I admire you guys that have the finesse or "touch" that can use power buffing on medium scratches without causing swirls or ripples. Especially on a clear acrylic windscreen shaped in a compound curve.

Instead of a 3 hour job...it would make it a 10 minute job, but alas, it is beyond my (current) skill set.

Cheers lads.

[movenon]

Thanks for the kind words Noel but...you should really see my garage...it appears that I have a hoarding disorder.
Remember, I've had my bike for 29 years now, and over the years, she has been down a couple of times so I've had some practice at repairs. I am now on my 2nd windscreen and I have a third oem windscreen tucked away in storage.

What I have learned in working scratches out of soft materials and dealing with the compound curve of the '84's windscreen is that.....
Giving 'me' a power buffer with a cutting compound is like giving a monkey a machine gun...

Power buffing for final polish is fine... I can do that.... although not for scratches.
I admire you guys that have the finesse or "touch" that can use power buffing on medium scratches without causing swirls or ripples. Especially on a clear acrylic windscreen shaped in a compound curve.

Instead of a 3 hour job...it would make it a 10 minute job, but alas, it is beyond my (current) skill set.

Cheers lads.

Throw a nice firm foam pad on there. It will make you a pro . Not that you not already !  , 29 years.......geeezzz..... That's a lot of polish !
George

[FJmonkey]

giving a monkey a machine gun...

Really Pat, did you have go THERE? I think I have a good feeling for being able to hit what I aim at, even with a machine gun. The UZI was quite controllable, almost like it belonged in the hands of a Monkey...