Preserving original glass
It is a myth to think glass melts as it ages. The waviness of vintage and historic glass did not get that way over time but, instead, is a consequence of imperfections in the production process. Because these imperfections make this glass appear more like stained glass, it has become a desirable imperfection. That’s why we use steam to de-glaze sashes. It is the safest way to remove glass without breaking it.
As hard as we try, though, we can’t save all original glass. But steam deglazing is not the only trick we have in our glass preserving bag. Consider this:
As the photo below shows, the long pieces of glass in this casement window are 5 feet tall. It seemed a shame to us to throw out the vintage “wavy glass” when only a small corner of the top left side of the glass was broken. So we offered this repair you see here. First we cut off the original glass to form a straight line. Then we salvaged and shaped a small piece of vintage, wavy glass. We glued it in place for a nearly invisible repair.