I bought this dark smoke 10 inch shield off of ebay and it's about an inch or two too tall. Not bad in the day, but at night it doesn,t feel safe. So my question is, can I cut it down? How, trim off the top, or can I cut the notches in the bottom deeper and then cut some off the bottom. What sort of saw, a jigsaw? Any other tips, techniques etc would sure be appreciated.

 

No problemo. Cut it off at the top. Mask it off (inside and out) with a good masking tape well below your desired cut and scribe the line you want with a marker (a pencil works fine). A template of the top curve will help. Use a fine tooth blade in a sabre saw. Move slowly and don't remove the saw blade while the saw is running or the plexi will shatter. File it down with a rasp and then a sand paper and block in stages until you're happy with the results. Take your time and be deliberate, you don't want to slip and scratch anything. Remove the tape and there ya go.

 

I had a spare windshiled laying around and wanted to take a few inches off the top. This worked but does not provide a show finish along the edge unless you trim from the bottom (dont know if the geometry will still work)and dont mess with the top.

Mine was cut from the top.

Take some heavy duty clear tape and apply it to the section you want to cut and apply on BOTH sides of the windshield.
Draw your "cut line" on the tape".
I made a template from a plastic 35gal. drum lid as the RotoZip tool I used will want to go in it's own direction.
Be sure to protect the windshield from the template to avoid scratches.
Using the RotoZip, I cut with template in place.
The rough edge was smoothed down with a 220 grit sandpaper. You will notice high and low spots/irregularities due to home-made template.

Once I smoothed the edge to where I was comfortable with the look, I applied a very thin layed of clear-coat nail polish. This eleminated the "haze".
Like I said, it will look home made but can be done.
Three weeks later, I bought a new tinted windshield.
I would not go through this again, if you can, replace the one you have with what you want. I dont think I would have the ***** to do this on a new one! Like I said mine was used and replacable.
My $.02 worth.
PS:
I would also try different RotoZip bits on like material to see which one provides a smoother cut.
Good luck

 

I've done a couple. I do work with plastic but it's not too hard if you're competent with tools.
Cover the outside of the shield with tape. Blue painters' tape works or even clear packing tape.
Draw the line you want to cut. Make sure it's even and smooth. You can follow the original contour or some use a compass or string to create a rounded top then taper to sides. Anyway, the line is important.
Next, cut close to the line with a jig saw.
Follow this by filing the edge until it's smooth and it follows the contour of the line. You can use a coarse file at first then a smoother one to remove the lines from the coarse one.
Lastly, finish with sandpaper. Use a block to further smooth the line you've cut.
Finish by sanding with finer grades of sandpaper until the edge looks clean. Usually 600 with a bit of water will give you this finish. Be sure to break the sharp edge of the cut area by sanding with a block at 45* a few strokes. It's easier than it sounds as long as you protect the shield from damage and make a good line to follow. You can clamp the shield in a vise as long as it's below the exposed area. Don't remove the tape until you're done.
If you're uncomfortable, look up your local plastics fabricator. They're in every town but they might charge as much as a new windshield.

 

Oh Yea, directions above it's pretty easy just take your time. A belt sander used carefully gave it a nice finished edge.

 

I did it a few times, came out great !! Like they said above......used blue painters tape...BOTH SIDES of the windshield. Use a NEW metal blade in a jigsaw. Also put Blue tape on the saw bottom. Use med speed for avoid melting. once cut, go over with file and sand paper. Once done put a little wax on the edge to seal. If you take your time, you will be very happy.

Be safe JIM

 

Yup, I've done this and it works fine. One thing I did was to trace the top of the windshield onto a piece of thin cardboard, and then cut along the line to give me a template of the old line. Then move it down to where you want the height to be. Notice that the template is narrower than the windshield, due to the curvature. Simply move the template to one edge, start from there and draw to the middle. Repeat from other side. Smooth out the middle section by freehand when done.

Finally, if you can't get the edges smooth enough acetone will take away any sanding marks. But if you get even the smallest drop on the surface of the windshield you will ruin it.

 

Here's good vid on steps. At 36tpi jigwaw blade should do trick.

http://www.youtube.com/watch?v=hQj05Db-C3c

 

Any good glass shop can do it for you for a few bucks and they can also polish the edge so it looks factory.

 

Last year in Cherokee NC one of my buds decided his windshield was too tall. We bought a used jigsaw in a surplus store, a new blade and used their power to cut the top off. He tried to sell the saw back to them but they wouldn't go for it.