Cutting a Lexan windshield is simple, if you know a few basic tips. Lexan is used for windshields on motorcycles, boats and cars. It is lightweight and doesn’t shatter like glass does. If you bought a windshield that's too high, you don't need to send it back, you can cut it down to size.
Marking the Cut
If you don’t know where to make your new cut, you can determine this easily. Put blue masking tape to mark the possible cutting line. Place the top of the masking tape along your cut line. The masking tape should be 4 inches wide so you cannot see under the masking tape. Now take a ride on your motorcycle. Can you see over the top after you’ve been riding for a while? If you aren’t happy with your cutting line, remove the tape and readjust it.
Making the Factory Cut
Lay the motorcycle windshield onto a piece of cardboard. Trace along the windshield's top outline onto the cardboard. Cut the piece of cardboard for a pattern.
Transferring the Pattern
On the inside of your windshield, place a strip of blue masking tape that is 2 inches wide. Center this over the cut line of your windshield. Place the cardboard pattern onto the windshield. Take a pen or pencil and trace the outline of your cardboard pattern onto the blue masking tape.
Which Side to Cut
If you are using a bandsaw table top, cut with the front side of your windshield facing down. Reverse this if you are using a saber saw, and also make sure you put the cut-line on the side facing up. Use a fine saw blade and this will help eliminate some sanding. Cut in a smooth steady motion. Don’t rush the cutting process.
Cover the windshield with a sheet, plastic, or thin cardboard. Plastic scratches easily and you will want to protect your windshield from scratching as you cut.
Stand the windshield upright. This will help eliminate scratches caused by the sanding debris. Use 80-grit sandpaper on a palm sander. If you don’t have a palm sander, you can attach a piece of sandpaper onto a wood block. Sand the edge for a second time using 220-grit sandpaper.
Factory Edge Finish
Buy some M.E.K. This is methyl ethyl keytone and it is a solvent that wil give you that factory finish. Take a small piece of cotton material that is only big enough to wrap over your index finger. Wet it with the M.E.K., but don’t make it dripping wet. With the wet cotton cloth on your finger, wipe the edge of your windshield in one smooth stroke. Do not spill M.E.K. anywhere on your windshield or it will melt the areas of your windshield that it hits. Also, use M.E.K. in a well-ventilated area or outdoors. The vapors are hazardous.