If some of the metal running across the front of your window air conditioning unit has rusted, treat the corroded surfaces by completing the steps below. Afterward, straighten metal pieces that are bent and apply a coat of a rust-inhibiting spray to metal pieces to prevent corrosion from becoming a problem again.


  • drop cloth
  • naval jelly
  • foam brush
  • scouring pads
  • coil cleaning agent
  • lint-free cloths
  • metal fin comb
  • rust-inhibiting sealer
  • face mask 
  • fan

Eliminate Rust And Dirt

Lay a drop cloth on the floor, directly underneath the air conditioner. Turn off the power to the air conditioning unit. Remove the air conditioning unit's cover and lay it on the drop cloth. Use a foam brush to apply a thick coat of naval jelly to rust spots that are on the air conditioning unit's cover. Inspect the metal components that form the air conditioner's condenser coil. Apply a coat of naval jelly to metal that is corroded in the same manner that you used to treat the rust spots on the cover. Wait several minutes for the rust to loosen.

Move a scouring pad back and forth over the rust spots to assist with removing them. Apply coil cleaner to metal surfaces are dirty. After the coil cleaner foams up, move a clean scouring pad rapidly back and forth over the metal that was treated. Use a sponge that has been dampened with water to remove coil cleaner that remains. Dry clean metal pieces with a lint-free cloth.

Straighten Bent Metal And Apply A Rust-Inhibiting Agent

Inspect metal that runs across the air conditioner's cover and interior components. Use the edge of a metal fin comb to straighten bent pieces. After placing the comb next to the pieces that are not aligned properly, firmly press against the tool to bend metal. Put on a face mask and open a window or turn on a fan to avoid breathing in harsh fumes. Open a can of rust-inhibiting spray and aim the product's nozzle towards the air conditioning unit.

Stand a few feet away from the air conditioner as you cover metal pieces with an even coat of the product. Apply a coat of rust-inhibiting spray to metal that is on the unit's cover. Wait for the inhibiting product to dry thoroughly. Once this occurs, reattach the air conditioner's cover and remove the tarp from the floor. Turn on the air conditioner to ensure that it is working properly. 

AC maintenance might seem difficult, but by following these easy steps, your system will be running better than ever before.