Are You Framing Your Windows with Zinc Correctly?

​Are You Framing Your Windows in Zinc ​Correctly?

Zinc framing around a stained glass window should be part of the structural backbone of your window. But if you aren’t doing it properly, it could be the weakest link in your project.

What's the Difference​?

​The difference between framing your heavy windows properly or just adding the zinc came around the edge without much consideration for weight distribution, reflects itself in the longevity of your artwork. If not laid out properly on the corners, the weight of the window can be too much for the zinc to hold over time, and the result is that the zinc pulls away from the window.

If noticed in time, the window can be saved. But left unnoticed, the window could come crashing down to the floor.

​A Visual Example of Poor Weight Distribution

Here’s a repair project that was brought to my studio that suffered from this exact problem.

Notice how the zinc pulled away from the window and bent? Luckily, the owners of the piece noticed it coming apart and were able to bring it down safely before it got any worse.

​The Solution

Always place the full length of zinc came from top to bottom along the left and right sides of a window. The top and bottom pieces should fit inside the vertical pieces of zinc where they are nestled in between these vertical pieces. The hooks would then be attached to the vertical pieces of zinc.

Like this.

This allows the weight to be distributed along the full length of the sides instead of relying on a single joint at the top that cannot possible bear all of the weight.

The Size of the Came Matters

Another point to be made about using zinc, is to ensure that you’re using the right size of came for the size and placement of the window. ​

The window repair shown in the photo is 25 inches x 28 inches. That’s more than 4 square feet which makes for a heavy window! In my opinion, this should have been framed in ½ inch came.

Why? Well, two reasons really.

Did you notice how this window has huge hinge points? Both vertically and horizontally?

Although the horizontal hinge is separated by a small area of solid glass in the center, it is still super flexible in these areas because the hinge is so long and there's so much weight to the window. It needs much stronger reinforcement to prevent those seams from bending.

Not sure what a hinge point is? I wrote two articles on what hinge points are and how to reinforce them

And the second reason is due to the sheer size of the window.

If ever you’re in doubt, just remember -  the bigger the better when you need the came to help with some hefty reinforcement.

Leave a Reply 8 comments

Laurel Vieaux - May 17, 2018 Reply

Quick question: do mitered corners make a difference in helping with strength? Or could I have been saving myself the effort of making perfect mitered corners all along by just using your format for the zinc?!?

Any work I do at the size of your example would only be done with lead came (along with cement) instead of copper foil…

Thank you!