How to Repair a Rusted Window Channel

Vacuum the sides and bottom channels of your window to remove all loose debris. Channels can be installed along all sides of a window. Only replace the channels if they become so damaged that the window no longer functions properly. A small rusted area is usually more suitable for a repair.

Spray a cleanser product into the channel and scrub the channel with an old toothbrush. Use a pointed stick or awl to remove grime from the corners. Wipe up the debris with a rag. Use cotton swabs to get in tight areas. Clean the channel down to as close to the finish or bare metal as you can. Channels often have drainage holes. Clean these well by inserting a thin wire into the hole and wiggling it around.

Remove rust using a wire brush. Scrub the rusty spot with the brush to loosen the metal pieces. Vacuum up the pieces. Sand the spot with folded sandpaper the width of the channel. Clean the metal until no rust remains. Open the drainage hole with the wire a second time in case more debris has gotten into the hole. Rust is usually caused by clogged drainage holes.

Wipe down the channel with a clean rag. Fill the hole with automotive body filler. Many automotive fillers are designed to be applied to raw metal. Use the filler to fill the holes. Smooth the filler with a narrow putty knife. Do not cover any drainage holes. Allow the filler to dry.

Sand the filler to make it level with the rest of the channel. Vacuum the debris and clean the drainage hole with wire. Tape off the window and surrounding wall areas with plastic sheeting. Spray the channel with a rust-inhibitor spray paint. Allow the paint to dry. Spray the channel with a white metal exterior paint to match the rest of the channel. Use thin even coats for best coverage. Allow 15 minutes between coats.