Is it possible to remove cured Hxtal from a glass piece and if so, how to do it safely for the glass?

Hello, You can use the epoxy solvent we sell called Attack. This will need to soak on the joint for quite a while and it will slowly eat away at the glue. This is a slow process and the larger the size the harder it gets to pull apart. Some people will anneal the piece again since hxtal will burn off at 500 degrees. This is smelly so have proper ventilation but works in order to burn it off it the Attack will not work.