How to remove glass from an old window in one piece.

Picture of How to remove glass from an old window in one piece.
After getting replacement windows for my house i saved the old windows thinking if several projects for them.  The major problem is several of the sashes are painted with lead paint.  No Martha Stewart you cant just paint over the wood.  At least not in Massachusetts.    So always take safety first.   Do this on a drop cloth like an old shower curtain.  Ware a dust mask.  Wash your clothes separately not with the kids.  Keep all kids away until after the clean up.  Also we will be using razor blades and have the potential for sharp glass.   

Sorry about the pictures there is no flash on my phone and the glass was transparent.

Your going to need
a razor both the double pointed (like in a box or dry wall cutter) and the straight edge both with holders
flat head screw drivers
soap & water
drop cloth
dust mask
small pliers (needle nose work goodgreen scrubby
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Step 1: Select the window

Picture of Select the window
Select  good window.  

Things to look for 
Hard dry Glazing putty that is falling out, cracked, pulling away from the wood.
no cracks in glass
rotten frame
no silicone holding window in 

Step 2: Carefully remove the putty

Picture of Carefully remove the putty
Go around the window with the razor blade inserting the blade between the wood and the glazing putty.  If the putty is old it should be cracking away from the wood and can be picked or snapped off.

The two things that you need to look for are
  1. Glazer points
  2. small bumps of putty stuck to the wood
Try to locate the points there should be at least one per side but there could be as many as three or more.  See picture for the different types of points you my find.  

Cut down.  Take your time make several passes don't rush don't push against the glass.  Make sure their are no bumps of putty that will hold in the glass.  There should be a knife thick grove between the window and the wood.  Watch out for points dulling the razor. 

When i have broken the pains it was because of these bumps or hidden points.
dkiehl10 months ago

I use a sharpening stone. They can be found at most hardware stores or hunting & fishing aisles in big box stores. Some have a rough & finishing grit on 1 stone. Another option is emery cloth pulled tight on a block of wood. Do not just wrap the emery cloth around the glass pane & think that you can do both sides of the glass at one time or you will end up with scratches that paint will become trapped in.

turbobug (author) 2 years ago
Some are sharp some not. At glass shops they have grinder i think sandpaper or a dermal would work.
floryhawk2 years ago
Once the glass is out of the frame, do you know a way to buff the edges so they aren't sharp?-- i.e. so you could use it without putting another frame around it? I have sheets and sheets of glass taken out of an office building, and I'd like to use some of it as a worktable of sorts, but can't figure out how to smooth the edges.
psullivan13 years ago
A cool glazer trick it to use a heatgun or torch on particularity hard putty. It helps a bunch, but will bubble paint or scorch if you leave it there too long. I repair these things on a daily basis. Mostly I just attack weak spots with a utility knife when I'm at someones home.
turbobug (author)  psullivan13 years ago
Good suggestion. Be careful when the paint starts to bubble the fumes are toxic. Ibbles get exponentially more views when you add flame or explosions.