If you've ever tried to remove an old window glazing putty with nothing but a putty knife and a hammer, you already know it is difficult. Decades-old putty bonds to the wood like concrete, and one wrong strike can crack the glass you're trying to save. There's a faster way, and it's called a putty chaser.
What Is a Putty Chaser?
A putty chaser is a small cutting bit that chucks into an ordinary power drill at either a 1/4-inch or 3/8-inch model. At the working end is a spinning cutter with a built-in guide shoulder. That shoulder rides along the edge of the window sash, which keeps the cutter tracking right along the putty line instead of wandering into the wood or the glass. Once it's seated and spinning, it chews through old, dried glazing putty in a matter of seconds.
Why It Beats a Putty Knife and Hammer
Hand tools work, but they're slow and hard on both the window and your patience. Old putty is brittle and unevenly hardened, so a hammer and putty knife can just as easily gouge the sash or crack the pane as clear the glazing. A putty chaser lets the drill do the work instead of your wrist, and because the guide shoulder controls the cut, you get a cleaner channel with less risk to the glass.
This usually comes first if you're replacing a broken window pane, clearing out the old putty is what lets you lift the cracked glass free and get the sash ready for glazing compound.
How to Use a Putty Chaser
- Fit the bit to your drill. Chuck the putty chaser into a 1/4-inch or 3/8-inch drill.
- Put on safety glasses. You're about to send old putty chips flying, so eye protection goes on before the drill does.
- Set the guide shoulder. Rest the shoulder of the bit against the edge of the sash, tip the tool down just slightly, and get a solid grip on the handle.
- Start the drill and let it track. Keep steady, even pressure and let the cutter follow the sash edge. You'll see it chipping the old putty away almost immediately.
- Clear the channel. Work your way around the pane until the sash shows clean, bare wood where the putty used to be.
Corded or Cordless? Why Torque Matters Here
Old glazing putty is dense, and cutting through it takes steady torque. You may want to consider a corded drill which would deliver more consistently than most battery-powered models. If you're weighing which drill belongs in your kit for jobs like this one, our rundown of commonly used power tools is a good place to start.
Once the Old Putty Is Out
With the channel clear, you're ready for whatever comes next. If you're saving the sash, that means priming the bare wood, bedding a new pane — covered step by step in our guide to repairing a broken glass window pane. If the sash itself is too far gone, or the window has just never been efficient, it might be a better time to look at a retrofit replacement window or, for a window that needs to come out of wood siding entirely, our walkthrough on installing a window in wood siding.
A Few Tips For This Project
- Wear safety glasses. Old putty and glazier's points can pop loose unexpectedly.
- Go slow near the corners. That's where glazier's points hide, and hitting one at full speed can send it flying.
- Watch your pressure. Let the guide shoulder and the cutter do the work, forcing the bit increases the odds of marking up the sash.
- Mind older homes. If your house predates 1978, have any suspect paint or glazing tested before sanding or heavy scraping.
