Different types of glue work to attach porous and non-porous surfaces. Glass is always non-porous, but canvas may be porous or non-porous. Don't worry if you're not sure of the classification of the canvas in your project; certain types of glue work to attach both materials, no matter the level of absorbency. Glue glass to porous or non-porous canvas using epoxy or construction adhesive for a permanent, clear adhesion. Hot glue also works to attach glass to porous or non-porous canvas, but the seal isn't permanent and the glue will yellow over time.
Squirt a small amount of one-part epoxy or clear construction adhesive directly onto the canvas and onto the backside of the glass object. Wait 60 seconds for the epoxy to activate.
Press the backside of the glass into the adhesive on the canvas. Hold the glass in place for at least two minutes before releasing it.
Tape the glass in place with painter's tape until the glue hardens if the glass begins to slide.
Mix the adhesive with the curing agent of a two-part epoxy glue according to the manufacturer's directions. Two-part epoxy dries faster than one-part epoxy or construction adhesive.
Apply a small amount of the mixed adhesive to both the canvas and the glass surfaces. Work quickly or the glue will begin to harden.
Press the glass onto the canvas and hold it for two minutes. Hardening times for two-part epoxy adhesives vary by manufacturer. Follow the manufacturer's directions to determine when you can move the canvas.
Insert a hot glue stick inside the back of a hot glue gun. Plug in the gun. Position the nozzle over the cardboard. Wait for the glue to begin melting. The nozzle will drip with liquid glue when the gun is ready.
Squirt a small amount directly onto the canvas where you plan to stick the glass. Press the glass into the glue, being careful not to touch the warm glue with your fingers.
Hold the glass in place for 30 seconds. Remove your hand. If the glass moves, reposition it and apply pressure until the glue hardens. Hot glue hardens in less than five minutes.
Do not rely on hot glue to attach heavier glass objects or rhinestones to canvas or any other material. Apply glue in a well-ventilated area.