Fiberglass reinforced plastic, or FRP, panels are a wall or ceiling covering usually installed over drywall. The product is sold in 4-by-8-foot sheets in a variety of textures and colors and is glued and riveted to the drywall. The thin, waterproof panels are suitable for installation in damp or wet areas including showers and tub surrounds. The thin panels require support while cutting. The plastic sawdust is messy; a saw with dust collector makes cleanup easier and prevents the dust from obscuring the cutting line.
Set two sawhorses with the crossbars 7 1/2 feet apart. Place the two-by-fours across the crossbars. Lay one plywood panel on one pair of two-by-fours, and the other panel on the other pair of two-by-fours. Leave a 6-inch gap between the plywood panels.
Lay the FRP panel on top of the plywood with the back side up. Measure and mark the panel at each end for a lengthwise cut, or on each side for a cross cut. Stretch the chalk line from one mark to the other and pull it tight. Lift the line about 6 inches and let go so it snaps against the panel to leave a chalk cutting line.
Position the cutting line on the FRP panel directly over the gap between the two pieces of plywood. The plywood will support the FRP panel while you make the cut. Clamp the panel to each piece of plywood to keep it from moving.
Install the multipurpose wheel on the handheld cutting tool. Set the blade depth to 1/4 inch. Install the dust port on the cutting tool and connect it to the vacuum cleaner hose.
Turn the vacuum cleaner on. Align the cutting tool guide mark with the cut line on the FRP panel, but do not let the cutting wheel touch the panel yet. Hold the tool firmly and turn it on.
Guide the cutting tool forward while keeping the guide mark on the tool aligned with the chalk cutting line. Continue cutting until you reach the edge on the other side. Turn the tool off.
Tips & Warnings
- If you have many panels to cut, use a single 4-by-8-foot sheet of plywood. The wheel will score the plywood repeatedly, but the convenience is well worth sacrificing a piece of plywood.
- When measuring and marking for your cuts, remember that FRP requires an expansion gap between panels. The small moldings in corners and between panels also use up a small amount of space.
- A rotary tool with a circle cutting attachment is useful for cutting large, round holes in the FRP panels.
- Wear safety glasses and an organic filter dust mask while cutting FRP. The smell of the plastic resin is bothersome to some people.
Things You'll Need:
- 4 two-by-fours, 8 feet long
- 2 plywood sheets, 2 by 8 feet, 1/2-inch thick
- Chalk line
- 2 clamps
- Handheld cutting tool
- Multipurpose cutting wheel
- Dust port attachment
- Vacuum cleaner