How to Replace Plexiglass Boat Windows

Updated April 17, 2017

Accidents happen and sometimes you need to replace the plexiglass windows in your boat. No need to take the boat to a repair shop and pay someone to replace the windows in your boat. You can do the job on your own, at a fraction of the cost.

Remove the old windows from your boat carefully by prying the plastic screw caps out with a screwdriver. Remove the screws with a Phillips screwdriver and place the screws and screw caps in a safe place for later use. You can use the old window as a template to make your new window the right size.

Cover both sides of the new window with blue masking tape to protect the plexiglass from scratches.

Trace around the old window with a marker onto the new window. Also, trace any holes you need for the screws.

Cut slowly and evenly along the line with a bandsaw. If you don't have a bandsaw, you can use a jigsaw or sabre saw. The size of the blade you need depends on the thickness of the plexiglass. Ask the salesman where you bought the plexiglass for the correct size of saw blade that you will need to use.

Drill the holes using a bit that is smaller than you need. Drill carefully, especially when you get closer to the other side. If you drill too fast or with too much pressure, you could crack the plexiglass. Drill the holes again, only this time use a slightly bigger drill bit than needed.

Remove the masking tape around the edge of the plexiglass. Stand the window upright and sand the edges with a palm sander and 80-grit sandpaper. Sand the edges a second time with 220-grit sandpaper.

Wipe the edge of the window with methyl ethyl keytone. Wrap your finger with a cotton rag and dip your finger into the methyl ethyl keytone. Don't get the cloth dripping wet, you just want to dampen it. Do not to spill any of this on your window or it will mark the surface.

Remove the masking tape and place on a sheet-covered work table.

Curve the window by clamping it on the work bench. Put a piece of cardboard between the window and clamp to protect the plexiglass from scratches.

Heat the bend line with a heat gun. Keep the heat gun constantly moving or the surface of the window will bubble.

Apply a sealant to the edge of the back of the window that faces the inside, not the exterior wall. Press the window in place. The caulk should be as thick as the diameter of a pencil, about half an inch from the edge of the window. Apply the caulk in one continuous flow for best results.

Put a grommet on each screw and then turn the screw in the holes. The screws need to go in straight; do not over tighten the screws or you can ruin your window. Cover the screws with a screw cap.  

Things You'll Need

  • Flathead screwdriver
  • Phillips screwdriver
  • Masking tape
  • Marker
  • Drill
  • Palm-sander
  • 80-, 220-grit sandpaper
  • Rag
  • Methyl ethyl keytone M.E.T.
  • Sheet
  • Heat gun
  • Clamps
  • Cardboard
  • Heat Gun
  • Caulk
  • Grommets
  • Sheet
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About the Author

Gail Delaney is a writer in South Dakota and has articles published online at various websites. She is the garden editor for BellaOnline, with years of gardening experience. Being the caretaker of her parents led her in the direction of medical issues, especially natural remedies.