woman behind broken window glass

Repairing Stained Glass: Tips and Techniques for Restoring Your Pieces

Repairing stained glass


Repairing stained glass is a delicate and intricate process that requires skill, patience, and attention to detail. Proper restoration is crucial for preserving the beauty and integrity of the glass.


Why proper restoration is critical


Stained glass is a fragile art form that is easily damaged by weather, accidents, or neglect. Over time, lead came weakens, solder cracks, and paint fades.

These issues obviously detract from the visual appeal of the piece. Additionally, time, decay, and neglect cause leaded glass windows to become structurally unsound.

When restoring stained glass, it is essential to use the right materials and techniques to ensure that the piece is returned to its original condition. With proper care and maintenance, your stained glass can be enjoyed for many years to come.


woman behind broken window glass

Identifying Damage


Types of damage that can occur to stained glass


Identifying damage in stained glass is the first step on the road to restoration. There are several types of damage that are common to stained glass.

Windows are exposed to sun, pollution, temperature extremes, and gusting winds. As a result, discoloration, cracks, breaks, and even missing pieces occasionally occur. Furthermore, vandalism and accidental damage add more potential for damage.


Properly assessing the damage


Look at the piece closely, checking for any cracks, breaks, missing pieces, or discoloration. In addition, examine the lead came for signs of cracking or weakening.

Identify any damaged areas, making notes of your findings, then decide the best way to fix it. Sometimes the damage is small and easy to fix on your own. In a case where you find extensive damage, you should consider getting a professional restorer involved.

It is important to note that not all damage is obvious and visible from the front. Therefore, it is a good idea to assess the condition of the inside and back of the piece as well.

While some beginners do learn to make suitable repairs, restoring leaded glass to its original condition can be challenging. Consult a professional restorer who has experience and knowledge in stained glass restoration to guide you, if needed.


Removing a stained glass leaded panel from its wooden frame


Cleaning and Preparing the Piece


Cleaning and preparing the piece for repair is an essential step in the restoration process. It is important to remove dirt and grime that may have accumulated on the glass and lead came over time. This not only improves the appearance of the piece but also allows for a better assessment of the condition of the lead or copper foil.


Steps involved in cleaning and preparing the piece for repair


Clean the piece using a mild detergent solution and a soft-bristled brush. Make sure to clean the glass surfaces of any accumulated dirt or grime.

Use a small brush and a mild detergent solution to clean any dirt or debris from the lead came structure.

Remove any old paint or patina. If there is any old paint or patina on the piece, remove it before proceeding with your evaluation. This can be done using paint stripper or a wire brush.

Look carefully at the soldered joints between the glass and at the lead came joints for cracks or missing chunks of solder.

Carefully examine and assess the condition of the lead or copper foil (if used) for any signs of damage, such as cracking or weakening.

Disassemble the piece, if necessary to gain better access to the glass and lead came.

Here is a free PDF download (link) titled:  A Brief Guide of Protective Glazing for Stewards and Caretakers of
Leaded and Stained Glass Windows from the SGAA.


Tools needed for cleaning and repair


Some of the things you will need include a mild detergent solution, a small brush, paint stripper and wire brush. Don’t forget to utilize safety gear like gloves and goggles.

It is important to note that cleaning and preparing the piece properly and carefully is key to ensure a good restoration outcome. Therefore, take advice from a professional restorer to guide you through, if you can get it.


Repair Techniques


There are several techniques used to repair stained glass, depending on the type and extent of damage. Some of the most common techniques include replacing broken or missing pieces, re-leading or re-foiling, soldering, painting or patina, and adding new glass. Each technique has its own set of pros and cons, and it is important to choose the right one based on the specific needs of your piece.


Replacing broken or missing pieces


This is one of the most straightforward techniques for repairing stained glass. If a piece of glass is broken or missing, replace it with a new piece of glass that matches the original in color, texture, and size.

One of the advantages of this technique is that it allows for a precise match of the original glass. However, finding a matching piece of glass can be difficult and may require custom fabrication, which can be costly.

The following video details the repair process of a leaded glass window panel.

Stained Glass Repair



Re-leading or re-foiling


Soldered joints of lead or copper foil can crack or weaken over time, and need to be replaced or repaired. Re-leading is the process of removing the old lead and replacing it with new lead. If copper foil was used, you may need to apply new foil to the edges of the glass.

Both of these techniques are labor-intensive and require a high level of skill. However, they can help to strengthen the structure of the piece and ensure its longevity.


Consider adding, expanding, or rebuilding reinforcement structures into the window or panel. Explore reinforcing stained glass here in my post entitled:

Reinforcing Stained Glass




Re-soldering is the process of repairing lead or copper joints using a soft metal alloy. This technique is used to repair cracks in the lead came or to secure loose pieces of glass.


stained glass door solder repair


The advantage of soldering is that it is done quickly and easily. However, it is important to use the right type of solder and to heat it to the correct temperature to ensure a strong bond.


Painting or patina


Some stained glass pieces have painted details or have a patina finish on the lead came. If the paint or patina is faded or damaged, it can be restored.

This technique can successfully restore the original appearance of the piece. However,  the process can be time-consuming as you attempt to match the finish.


repairing glass in a stained glass window



Adding new glass


If the damage to the stained glass is extensive, it may be necessary to add new glass to the piece. Typically, this technique is used when the original glass is no longer available or when the damage is too severe to repair.

The advantage of this technique is that it allows for a complete restoration of the piece. However, it can be difficult to match the original glass, and the process can be costly.


Pros and cons


These various techniques used to repair stained glass damage each come with their own sets of pros and cons. Replacing broken or missing pieces is highly effective, but it can be difficult to find a perfect match and it can be costly.

Re-leading or re-foiling is relatively inexpensive and quick, but it can be difficult to match the new lead or foil to the original. Soldering is quick and easy, but, again, matching the color of the replacement solder to the original can be difficult.

Take the time to try different products and methods to achieve the closest match to the original style, texture and color. Ultimately, the best technique for repairing stained glass damage will depend on the specific repair project and what is most important to you.


Finishing Touches


Once the repair work is complete, it is important to properly finish the piece. Ensure that it looks its best and is protected from future damage.

Proper finishing touches include cleaning and polishing, applying a protective coating, and re-hanging or installing the piece.


Cleaning and polishing


After the repair is complete, thoroughly clean and polish the piece to remove any dirt or grime that may have accumulated. Use a mild detergent solution and a soft-bristled brush to gently clean the glass. A microfiber cloth is your best option to polish the glass to a shine.


Applying a protective coating


Apply a protective coating to the glass to help protect it from future damage. This can include a clear coat of lacquer or a UV-protective coating.

Applying a protective coating will help to protect the glass from discoloration or cracking caused by exposure to sunlight, heat, or pollution. A quality coating used by professionals is Clarity finishing compound (link).


Re-hanging or installing the piece


Finally, it is important to properly re-hang or install the piece to ensure that it is secure and stable. This can include installing a new hanging system like this one (link), or reinforcing an existing one.

If the piece is to be installed in a new location, it is important to make sure that the location is suitable for the piece and that the piece is properly secured.

It is also important to keep in mind that when the repair process is finished, the piece will need a maintenance check up at regular intervals. This will ensure that the piece remains in good condition over time.


In summary


Repairing stained glass is a delicate and intricate process that requires skill, patience, and attention to detail. Proper restoration is crucial for preserving the beauty and integrity of the glass. With the right knowledge and tools, you will achieve a successful repair.

We have talked about different ways that stained glass gets damaged, such as cracked or broken glass, missing pieces, and discoloration. Additionally, we have outlined the different techniques that are used to repair stained glass.

And finally, we talked about how to properly finish the piece after the repair. These steps include cleaning and polishing, applying a protective coating, and re-hanging or installing the piece.

Read about all the steps and methods used to build a stained glass window at our post titled: Creating a stained glass window (link).

If you are unsure about the condition of your piece, seek a professional appraisal. While anyone can learn the required steps, it is important to note that repairing stained glass is not easy. It’s always a good idea to seek professional help if you are not comfortable attempting repairs on your own.

Take care of your repaired stained glass piece and it will last for many years.