All About Wavy Glass

By Scott Sidler June 13, 2016

all about wavy glassLots of us appreciate the wavy glass we find in our old windows. Some don’t even know what they have, but for those of us who have taken note of the unique appearance of wavy glass the new stuff just won’t cut it.

Old glass has bubbles, waves, inclusions, varying thickness…all kinds of beautiful imperfections and that’s exactly why we love it! I’m sure I’m not the only one, but to me modern float glass is too perfect. There’s no character, no uniqueness. Every window looks the same and its perfection is like monolithic splendor run amok.

I want the character. I want the history. I want something perfectly imperfect, and wavy glass is just that.

A Short History of Glass

For years the only glass available was hand-blown glass. It was expensive and large sheets were not available. A local glass worker would blow the glass on a rod and spin it into discs which when cooled could be cut into small pieces.

That is why homes built in the 1600 and 1700s have so many small panes of glass in their windows. Price and availability of glass dictated window designs and lite patterns.

antique cylinder glass
A piece of cylinder glass ready for cutting ca. 1918

Later as technology improved in the early 1900s machine drawn cylinder glass was introduced. This process drew large cylinders of glass vertically from a machine. These cylinders could be upwards of 40 feet tall!

They were then cut into smaller cylinders of 7-10 feet typically before being cut lengthwise and reheated to flatten them into one big sheet from which the glass could be cut according to the window maker’s needs.

Then around the mid-20th century float glass was invented which is how we get modern glass. The molten glass is poured out onto a bed of molten tin which allows the glass to “float” on top and level out perfectly to remove any imperfections.

With float glass you get perfect pieces of glass. Perfectly boring!

Where to Find Wavy Glass

Probably the best place to find wavy glass is the curb. Sadly, so many people throw out their original windows to get replacement windows. If you’re new to this blog you’ll learn that replacement windows (or disposable windows as I have come to call them) are a terrible idea and not worth anyone’s time or money.

Finding old windows at the curb to salvage the wavy glass is how my company has created a large stock pile of the stuff. But if you can’t find any laying around the first-rung neighborhoods in your town then there are some other sources you can turn to.

Architectural Salvage

Search your local architectural savage yard. Most larger cities have at least one or two of these shops in the area. Antique shops might be another place to check, but you won’t get the kind of deals you will find at salvage yards. For between $5 and $50 you can often walk away with some old glass. It just depends on the size and waviness of the glass how much you’ll spend

AGW Old Style Glass

AGW makes some great wavy glass in several different grades of waviness to help you match the glass to the age of your project. You can also order samples to find the options that works best for you.

Hollander’s Restoration Glass

Hollander’s manufacturers glass that is similar in appearance to the wavy glass of old. It may not have the history of antique glass but for appearances it looks a lot closer than float glass. Hollander’s also has several grades of glass to match different age buildings.

Bendheim Restoration Glass

This restoration glass company has been around since 1927 in New Jersey. They have different options of wavy glass and also offer antique style mirror glass.

Between these options you should be able to find a sufficient solution to your old glass needs. Always keep an eye out on the curb for some free old windows though. You may be luck enough to snag some of the best old glass just waiting for the garbage truck.

Pioneer Glass

Another great manufacturer of wavy restoration glass in several grades. They can even put together wavy glass IGUs if you should need.

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12 thoughts on “All About Wavy Glass”

  1. My name is Nancy. I have to replace all the windows in my Mother’s house. built in 1840, and the windows are still the originals. Should I ask them to save the glass…is there anyone out there,
    that would want this old historic glass?

    1. Nancy, don’t throw it away! If you must get rid of the glass, at the very least, offer it up on craigslist or contact your local architectural salvage depot.

  2. I’ve been a professional window cleaner over 35 years. I LOVE old glass for it’s imperfected character! We use water with small amount of dish soap , usually Dawn or Joy, scrubbing with a ‘wand’ (imitation lambs wool or microfiber on a T-Bar) and a good squeegee. This cleans any glass new or old. The angle of working the squeegee has everything to do why people gets streaks. All this can be bought at Lowes in cleaners dept (Ettore). A non-scratch pad (usually 3M white pad, or kitchen sponge) will remove most stains and nasty baked-on dirt & grime, bug stuff and won’t scratch glass. The scratches you now see were most likely already there and are visible now that the glass the is cleaner, just like the comment above. Your glass, remember, is probably 60-100+ years old and has seen a lot! Hope this helps!

    1. The author explains that glass was once hand blown, flattened and spun into a disc. This early method did not create perfect glass like today, so I guess the spinning process resulted in it being wavy.

  3. I purchased a 1955 house with wavy glass in 9 of the windows. I get frost build up on 3 storm windows, when the wind blows. The storms must be a bit newer because they’re metal, with non wavy glass. I assume
    the air leakage is with the storms, but honestly I can’t see where they’re leaking air.

  4. What about cleaning the old glass? I had a contractor clean my antique glass with newspaper and vinegar and water and I’m convinced the paper scratched the glass. Could that be possible? I want to warn people away from this if true.

    1. Paper won’t scratch the glass. I recommend cotton cloths and windex or a basic cleaner like vinegar. More than likely once the Windows were clean the scratches that were already there were just more apparent.

    2. As a stainglass restorer , I can assure you that this a good way of cleaning old windows. Those scratches were there before or appeared in the restoring process for a reason or the other .

  5. Excellent email Scott! I am myself a stain glass and old vintage windows and doors; always thriving for the authentic style. Tx for your work.


    1. Hugo. I am trying to find information about some vintage sash wooden windows I just purchased w unusual etched privacy glass. Do you know where I can find information on them They are 4 pane and 44″ x 33″ and very pale blue w a design like lines going one direction and the next line going opposite direction. This repeats all the way down the window on one side only. Other side is not etched. Thanks for any assistance. Jeanie in C Fl

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