restoring windshield

[ArrrGeee]

for those of you with yellowed and scratched windshields, I found some info on the net to bring it back from the dead.
step by step instructions.


"The damage to your acrylic windows can be removed successfully if you
understand the nature of the damage and the restoration process.

Unless the acrylic is cracked, the damage does not go all the way through,
and all damage can be removed by removing enough surface material to get
back to virgin acrylic.  This can be accomplished with sandpaper, strange
as that may sound.  That's how it's done on the very expensive windshields
and windows in airplanes. As a company, we previously offered a sanding
system in kit form, but no longer do so. We are windshield manufacturers
and no matter how careful we are, sometimes we damage panels in the
factory. We use the method described below to remove defects in new
windows. You can obtain the materials you need locally to successfully
restore your own acrylic windows and hatches.

Start with 220 grit abrasive, wrapped around a foam block, and sand in ONE
direction only until all damage is removed.  Do not use circular motion
for any steps; only straight line sanding. All steps can be done wet or
dry, depending on paper used, but wet is preferred. Most of the repair
time will be spent on this first step, so take yourwill still be there
when you finish.

Always increase the sanding area slightly with each successive step. Spot
sanding in a small area is to be avoided. As you move to finer and finer
grades of paper, change direction 90 degrees with each step, going from
horizontal to vertical to horizontal, etc. Flush with water after each
step, and don't go to next step until the entire sanding pattern from the
previous step has been removed.

After the 220 grit paper, go to 400 grit. Next move to 1500, 2400, 3600
and 6000 grit. These are available at any good shop that sells
cabinetmaker supplies. You don't need very much (one sheet of each grit is
plenty for most boats). Just take your time and keep flushing the window
during and after each step. After the final step, a good commercial
plexiglass cleaner is all you need to finish.

Keep in mind:

Always use a sanding block; free hand sanding will get you into trouble
with distortion
Use straight-line, even pressure; stroking in one direction only (
vertical or horizontal) Never use a circular motion
Do not bear down hard and lighten pressure at end of each step-check
scratch pattern frequently, using a light if necessary
Never move to the next finer grit until the the entire previous scratch
pattern is removed

Don't be afraid to do the job. You'll not only be happy with the results,
you'll be amazed how easy it was! (and your total investment will be 6
sheets of sandpaper)

Good luck!

Jesse
Sportvent Division of Vantage Point Marine  <VANPT@aol.com>"



-Ron

[Lucky]

so one question, would you need to both the inside and outside of the windshield? i'd imagine so..

also, this might be an acceptable solution for the yellowed window in the brake master cyl... (wich would be lots easier since it's tiny!)

--Lucky

[ArrrGeee]

I'm working on mine this afternoon and I can't get all the specified sizes, I started with 400,  rubber gloves and a bucket of water. just as an experiment I then went to 600 and then 1500. I bought a buffing wheel for my drill and then went to town with it and some plastic scratch remover from a boat store. it's a whole lot better than it was, I'm still not done. what I'm seeing is that I didn't get all the scratches out at the lower grits and will need to try and get them out as well as find the finer sizes. it's pretty amazing really that you can take sandpaper to your windshield to fix it.
it looks like all the damage is on the outside of mine, I wished I had left the inside alone.

so, is the master cylinder plastic or glass, I thought they were made out of real glass.

-Ron

[MotorPlow]

Ron,
My windshield was extemely yellowed.  In fact, it was so yellowed that you could not see through it.  When the light reflected off of it, any light, it looked like there where swirled scratches in iit.  It was truly nasty.

I used this system: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=13727&item=6101638285&rd=1 Novus Plastic Polish, 3 step process.  (Heavy Scratch Remover, Fine Scratch Remover and Finishing Polish)

It took about an hour total and now my windshield looks pretty close to new.  Crystal clear and in damp weather, the water beads up on it and whisks itself off the plastic.

Try it first, before you get agressive with the abrasives.

Good Luck,
Chris

[Bruce]

I did this a few weeks back and was pleasantly surprised. not quite new, but quite nice.

Bruce.

[Lucky]

the m/c window is plastic

[ArrrGeee]

just some more observations.
after some further research on the subject, sanding it would be the best option if the plastic is pretty well trashed (as mine was )
the trick is in the wet sanding with finer and finer grits.
it is actually the way that they make optical lenses.
for example, when you connect fiber optic cable, you need to polish the ends to ensure that no light is lost at the connection using... microfine sandpaper.
I actually knew this a couple years ago when I took a fiberoptic cert course through work, but never really thought you could do that to your windshield.

one interesting fact is that when you get to the finer grit sizes they make scratches that are so small that they cannot be detected by the human eye.

here is a link for a kit you can buy with the finer grit sizes.
http://www.woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM=119-522

this is the second or third time I've played around with the windshield on my bike. I used the plastic scratch remover stuff the first 2 times and while it was better, it still was kind of foggy and yellowed. not only that after about a month it looked about the same as before.
right now after going over it with 320, 400, 600 and 1500 and then the polish stuff it is much clearer then when I first got the bike.

-Ron