Stained and Leaded Glass Repair

Here we give guidance on cleaning and repairing stained and lead glass. Do not attempt repairs in stained glass i.e. glass with a painted pattern, unless you are very proficient; instead please involve an expert.


If the glass is fragile, very decorated or important, seek expert advice. Use a little grate polish on a soft cloth on the lead rubbing, across the cames. To clean the glass, use warm soapy water on a soft cloth. Use an old toothbrush to clean the glass close to the lead joints. Avoid any abrasive chemicals.


If you have a lot of patience and a window which:

  • is leaded, with no stained glass
  • is less than, say, four square feet in size
  • does not have much broken glass

you can try to do it yourself.

If the putty in the cames has fallen out, then carefully pick it out. Prepare the putty by working it. Then feed a thin ‘sausage’ into the gap between the lead and glass, pressing it in with a knife. Work from both sides. Finally cut off the surplus. There is no need to paint it.

Some Warnings

Do not attempt to take the leaded glass panel out of the frame unless you are prepared to repair or to pay for an expert; the outer lead is usually perished and fragile.

Never hold the window horizontally unless the glass is supported with saddle bars i.e. metal rods.

Always hold the glazed panel vertically, and support it with a stiff board when lowering it to the horizontal.

Be patient. Do not hurry this job.

If the window is intact except for cracked panes, consider using 'super glue' to fix them rather than trying to rebuild the window.

Equipment and Parts

You will need:

  • a soldering iron with a rating of 80-100 watts. Note that the gun type cannot produce enough heat; they cannot be operated continuously.
  • lathekin; a wooden or plastic knife for opening up the lead calms and smoothing them down
  • palette knife
  • glass cutter
  • pliers and pincers of various sizes
  • a stiff wooden board larger than the glazed panel
  • two lengths of 20x5mm wood as guides
  • glazing nails to pin the lead in place as the window is rebuilt
  • flux
  • solder
  • putty
  • grate polish
  • calms (also called cames) of appropriate sizes
  • replacement glass
  • copper wire for ties
  • 'super glue'


Preparing the Panel

Once you have removed the putty, remove the nails. These may be tiny flat-headed nails driven through the lead.

Snip any tie wires.

Set the frame vertically. Slide a palette knife between the frame and the window, easing the panel out; avoid flexing the it.

Lift the panel out vertically, and rest it on the floor or table. Be prepared for the lead frame to fall apart; glass panes may fall out if loose.

Holding the panel in one hand, bring the board up behind the panel on the side where there are no tie wires. Using the board as a support, lower them both to the horizontal.

Dismantling the Panel

If the outer lead is white and perished, you have to remove it. Slide the panel to the edge of the board, each side in turn. Use pincers to snip the lead into pieces, avoiding damage to the calms which join to it.

If any outer glass is loose, remove these pieces, noting their location.

If central glass needs to be replaced, you can either ease up the lead calm around the pane or dismantle the lead more completely.

Use the soldering iron to melt the solder attaching the edge calms from the outer lead. Apply flux to assist the melting. Discard the bits of outer lead.

Unsolder any wire ties.

Clean out dry and loose putty from the calms.

Turn the panel over using the board to support the glass, and remove the edge calms from the outer lead on the other side.

Rebuilding the Panel

Stretch the lead calms so they are straight; grip one end in a vice and the other in heavyweight pliers. Using the weight of your body, pull the lead.

Cut the lead roughly to the lengths needed.

If you have dismantled the window extensively, nail the wood guides at 90 degrees on the board. Prepare the edge lead, mitring the corner. Clean the join carefully with a file. Pin the lead to the board with glazing nails. Apply the flux and solder the joint. Rebuild the panel working out from these edges.

If you have not dismantled the complete window, clean any broken joins in the existing lead by filing the joins. Apply the flux and solder each joint.

Mitre and refit the outer lead, soldering it to each of the edge calms after cleaning them carefully, not forgetting to replace any glass you had removed. Once you have completed the side, turn it again and repeat.

Reglaze or glue any broken panes.

Mix putty with a little grate polish. Then, gently, work the putty into the joins between all the glass and the lead. Then use a soft brush like a shoe polishing brush to buff it off. It is a messy job but gives a consistent look. Do be gentle though.

Using the lathekin, run it up and down to press the new calms onto the glass. Be very careful or you will crack the glass.

Turn the window again and repeat with the putty and lathekin.

Turn the window once more and solder on new wire ties if necessary.

Well done if you have got this far.

Now reglaze the window. Again, keep the panel vertical. Make sure you place each panel in the correct frame and the right way round. Using pliers, twist the tie wires behind the saddle bars.

If you are rebuilding a sash window, reassemble it.