[dsraven]

tip: on the ends of the cut where the zip disc is too big to fit you can try a jigsaw spaced off the work with a piece of wood or whatever so it doesn't hit the blade on the outside part of the frame behind, or use a hacksaw blade without the hacksaw frame and with tape on the part you will grip. a row of holes drilled with a small bit makes short work of that and then a die grinder with a burr cleans up the poor cut down to the proper finished edge. a pneaumatic cut off tool also works well. I have an assortment of the zip discs and also cut off tool discs that are used but not worn out and they come in handy to get closer to those corner style cuts, but they don't make it all the way in.