What do you mean here AL?
....back it with a 6" wide board...
Are you holding the backer vertically?
Are you laying the workpiece flat on the table and "chewing" the waste away by multiple cuts?
I don't understand..... :blink:
If you hold the work vertically, it may get cumbersome if it's 3 or 4 ft long, like on a table leg or stretcher. I had to make a kerf in the end of a replacement bed rail a while back for the existing hardware, it was all I could do to manage the height. Others later suggested laying the work flat on the bench and using a circ saw. If using a table saw, the tenon length is limited to the maximum height of the raised saw blade, usually about 3" or so.
Actually, with a fine tooth blade, the bandsaw can make some fast and easy tenons. :yes: