how are you cutting the gaurd? you have to go sloowwwwwww. i cut a narrow slot with a fine toothed hack saw or coping saw and then go to town with an 8 inch file, after getting close i use needle files.
all of my gaurds arefriction set also, meaning the slot is just barely undersized and i tap it onto the blade with a hammer with a piece of leather over the head so it doesnt ding anything up.
then glue it to the blade with jb-weld, before it cures cut off all of the excess.
it usually helps to have the handle allready shaped before installing the gaurd also, that way you can angle the guard to the handle not the handle to the gaurd