The glass gasket is very thin, but a little squishy. It is a fiberglass material that will compress a little bit. It goes around the edge of the glass in a U-Channel shape. Going from one side of the glass across the edge of the glass and over to the other side.
The glass gasket that we recommend is called a tape gasket. It also has the gasket glue pre-applied to one side, so it is sicky, like tape. This makes installation of the tape gasket a breeze.
Most of the time you don’t have to worry about sealing the woodstove glass until you are replacing the glass. But, sometimes the glass gasket will breakdown over time. The gasket will start to denigrate to almost like a powder. If this happens then you will want to carefully remove the glass. I say carefully, because the glass also becomes more brittle with time and can be extremely fragile.
After you put the woodstove glass gasket on the glass, put it back in place. However, be very careful putting the glass clips or brackets back on. You want to screw these back in very carefully. If you overtighten the screws, you can crack the glass.
You want the screws put back in place what we call “finger tight”. Meaning, screwing them in by hand right to the point that the glass is held in place, right when the screw starts to give you some resistance. If the glass is installed too tightly, the glass can brake from expansion when the stove heated up.
Remember, you are just trying to create an air-tight seal between the glass and the woodstove. You don't want to pin the glass in place. The ceramic glass should be free to have a little movement for the expansion of the metal when it heats up.
If your careful, you should have no problem. Just keep in mind that the ceramic glass used in woodstoves is not any stronger than normal glass, it can just withstand much higher temperatures.
If you would like, here is a video showing the installation of a ceramic glass and wood stove tape gasket. gasket installation video