A handle has come off my aluminium double glazed window frame. The back plate appears to be zinc and has broken. Does anyone know a metal to metal glue THAT WORKS? I've tried Araldite 2-mix, Liquid Metal from 'evo-stick'. They seem to have worked but the handle, which is fitted to the backplate and tightened by a grub-screw pulls away. The adhesive is little better than chewing gum. Please don't suggest I use chewing gum!! Can anyone help, please?