Steel windows – rusted frames

Cause

Exposure to air-borne salt, dust or dirt; atmospheric moisture

Repair

  • if the window is basically sound and the damage is relatively minor or limited to certain areas, repairs may be possible without removing the windows. The glass and putty should be removed and then any rust removed with scraping and sanding. Prime the steel frame with a zinc-rich primer. Reglaze the frames. Paint using a product designed for use on steel, making sure there is a good seal over putty, glass and frame
  • if you want to retain the frames but the damage is more than minor, repair may be possible but is likely to be expensive. Remove the windows and remove the glass from the frame. Any paint, putty etc. should be completely removed so the frames are just bare steel. Sandblasting may be the fastest way to achieve this. You may wish to use a rust-removal product. (Be aware that some of these include a significant amount of phosphoric acid, so considerable safety precautions are required.) The frames should then be given protection which, depending on local availability, may be hot-dip galvanizing, zinc plating or applying zinc-rich specialist paint primers. Paint using products designed for use on steel. (Depending on availability in your area, powder coating may also be a possibility.) Reinstall the windows and the glass
  • there are companies in New Zealand that specialise in repairs to steel windows. You could ask them for advice and a quote
  • if the window is severely affected by corrosion, or the poor thermal performance of the windows is causing high electricity bills for space heating, replacement with a different type of window with better performance may be the best long-term solution. Steel-framed windows have very poor thermal performance because steel is highly conductive and heat is quickly lost to the outside

 

Cause

Galvanised protective coating (if galvanised) has eroded

Repair

  • as for first repair above

Cause

A deteriorated paint finish has exposed the metal

Repair

  • as for first repair above