Yes, HXTAL will bond metal to glass with a few caveats.
When bonding glass to metal you have to take into account the fact that these are two very dissimilar materials with two different rates of thermal expansion. If you leave a thin joint of HXTAL to bond these two materials, the resulting stress on the epoxy may well tear your piece apart (remember that HXTAL if oftentimes stronger than the glass, so if it pulls apart from stress it will most likely break your glass before it fails the joint).
You will need to create a thicker joint of HXTAL to accommodate the different rates of thermal expansion and reduce the stress on the joint. You can mix your HXTAL and allow it to sit and thicken up to create a thicker joint between the materials (oftentimes up to 1mm thick or more).
Depending on the type of metal you are using, you may also need to evacuate any moisture that has been trapped in the metal. Many metals are porous and will retain water from the air. When you bond the metal with HXTAL, the resulting heat created by the chemical reaction will bring that moisture to the surface of the metal and your HXTAL will bond with a thin layer of water that will evaporate and cause a glue failure.
Using a torch to heat the metal will generally evacuate any water that the metal has retained before adhering with HXTAL.
We also now offer 3M's DP-105 epoxy that is specifically formulated for glass to metal bonding. We also have our visible light cure VIS-470 that is excellent for bonding flat glass to metal.