Metal frames
To fit a new pane of glass into a metal frame adopt basically the same method as for a wood one except you must use metal casement putty, since linseed oil putty is not suitable for metal. The glass is held in place by special glazing clips rather than sprigs – one arm of the clip slots into a hole in the rebate, while the other arm of the clip clamps onto the face of the glass. Hack away the old putty and note the positions of the glazing clips so you will know where to refit them. Remove the clips from the frame (if you do this carefully, you will be able to use them again). Brush the rebates clean, apply a coat of metal primer and leave to dry for a few hours. Spread a layer of putty in the rebates and fit the new pane of glass into the frame on the putty. Replace the clips in their original positions and finish off as for a wood frame.
When handling broken glass, wear protective spectacles and a pair of old, preferably leather, gloves. Keep children and pets well away until you have finished the job and every piece of glass has been cleared up. Wrap the glass in newspaper and put it straight into the dustbin to avoid accidents.