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August 26, 2007

How to fix a broken window OR make a mirror from an old window

Hung_100_dpi Glass Backwards - Revive a busted window or convert it to a mirror

 Everyone should know how to fix a broken window because projectiles happen. And behind every projectile is a surprised child, so you might as well teach your kids how to fix broken windows too. It’ll save them years of allowance.

Now, if you live in an apartment or condo and you never get pelted with baseballs or rocks, I know how disappointing that can be. But take heart, because you can use these glazing techniques to create a cool mirror from an old window.

There’s nothing quite so noble as an old window. It has a special look that says “I’ve been through some stuff.” Like the look of a married guy who’s nearing the end of his mid-life crisis and still hasn’t bought a sports car or shaved his head or daydreamed about the cashier in the Tim Horton’s drive-thru. It’s a look that says “I can hang on a little longer, but it better be worth it.” And that’s darn attractive in a man. Or a window.



You can find old windows at building salvage supply outlets, which are all the rage in Europe and just beginning to catch on here. 

Great local salvage is available at Habitat for Humanity ReStores, which offer both new and used building supplies at reduced rates.  To find ReStores in Canada, visit www.habitat.ca


Stuff You'll Need:

Glass or mirror

Glass cutter

Glazing compound

Glazing points


Safety glasses

Putty knife

Wire brush

Fine-tip marker


Pane in the Glass

Whether you’re fixing a single broken pane or replacing them all to make a mirror, don safety glasses and gloves, and start hacking out the old putty. Depending on the acumen of the last person who fixed the window, you will probably become seriously irritated. If the former handyperson was winging it, you might be chipping out rock-hard epoxy or even ossified Playdough. Human ingenuity has no limits. Well, it does, but that’s never stopped a fix-it enthusiast.

Removing_the_old_putty_from_the_winOnce you’ve scraped away all of the putty (or unidentifiable putty substitute), carefully remove the glass.

Safety Tip:

Dispose of broken glass shards by placing them in a cardboard box or heavy paper bag prior to depositing them in a garbage bag. This will prevent dreaded “poke-through” injuries for whoever takes out the garbage.


Cut Instincts

Use a wire brush to clean up any remaining debris clinging to the frame. Next, measure the dimensions of the grooved edges that formerly held the windowpane. Subtract about 1/8-inch on both length and width, because you want the new glass to fit loosely in the enclosure.

Cut glass to match the dimensions you need. This is fantastically easy. You need a $5 glass-cutting tool, which is nothing more than a handle with a tiny cutting wheel at one end.

Cutting_the_mirror_with_a_glass_cut Wearing gloves, mark a line on the surface of the glass (or mirror) with a fine-tip marker, and then place a ruler alongside the line. Put the glass cutter against the edge of the ruler to ensure a straight cut. Then, putting pressure on the wheel, score a line alongside the ruler. You should hear a searing sound as the glass crystals part under the force of the wheel.

Tip:  Run the wheel of the glasscutter through a drop of vegetable oil to lubricate it prior to scoring.


Once you’ve scored the line, bring the glass to the edge of the table. Place the marked line directly over the edge of the table, and then bring the overhanging glass down firmly over the edge, causing it to snap along the scored line. You might feel spikey the first few times you try this, but you’ll soon find it’s a lark compared to trudging all the way to the hardware store to get somebody else to cut it for you.

 Fits and Pieces

Drop the glass into position to check fit. If it binds, try reducing it by gnawing on the tight edge with a pair of “grozing” pliers, available at stained glass stores. Or just save that piece of glass for another section, and cut a fresh piece a tad smaller.

Installing_glazing_points_with_a_pu Lock the glass in place with glazier's points, little metal wedges that are easily driven into the wood frame with a putty knife. One point every four inches is about right.

Okay, if you’re making a mirror you’re DONE! Hang that baby. Strut a little. You’ve just acquired your own antique wood-frame mirror and saved yourself about a hundred bucks.


The Putty Professor

Now, if you’re fixing a window rather than making a mirror, this is your big chance to be a hero to the next hapless soul who busts a pane. Use real glazing compound, aka window putty, and not some goofy alternative like 30-year exterior caulk or marine epoxy or Bondo.

Knead a ball of putty in your hands until it’s pliable. Roll it into a half-inch thick worm, and then press the worm into the joint so it makes good contact with both the glass and the wood frame. Finally, smooth the putty with a putty knife making a nice 45-degree angle that looks stunningly tidy. Remove the excess. The putty takes about a week to cure. At that point you should touch up the paint where necessary so there’s no bare wood showing.

Was that fun or what? There’s nothing like blasting through a project and then relaxing with your favourite beverage. Which reminds me, it’s beer-thirty.




How do you make an antique mirror from a pane of glass?


Mag may have meant to mention that some hobby and craft stores sell mirror paint (it's a sort of high-gloss enamel chrome spray-paint made for glass). Making traditional glass windows requires silvering and is rather hard to do at home


The way they do it in a factory is put a super-clean piece of glass in a vacuum, then sputter, or boil the silver or other metal under the glass so the vapor from the metal deposits on the glass in a thin layer.

If they do a very thin layer, it becomes a "dichroic filter", which is best as a colored light filter for stage lights. The color of the filter depends on the metal used.
If the layer is a little thicker, it becomes a one way mirror like those used in interrogation rooms. (Usually placed in the shared wall between 2 rooms, it acts as a mirror on its brighter side and a window on the darker side. The interogation interview traditionally takes place in the brighter room, while officials, experts and witnesses may view the proceedings in the darker room) If a little thicker layer of metal is deposited, it becomes a regular mirror.

Hope this helps.


Wow, Orchus! You know stuff! Thanks for the primer on mirrorizing. I'd been all set to try it with silver leaf and sizing, but I know the square shapes of the leaf would be obvious so it didn't seem like a good ersatz solution. I love the chemistry approach - isn't it weird how you can really like something in adulthood that you sucked at in high school?
Thanks again for the links and info. Very good of you.


How to make a new mirror look old

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