I was wondering whether anyone is used to using a lathe and whether I should cushion my three jaw chuck with nylon for gripping machined 7075 T6 aluminium or not?
Depends what your doing to it? If your going to be turning a piece that can then be cut from the of the original billet, then no, but if you've already turned the end that you're putting in the chuck, then yes, I do. I've always just wrapped it up in a wad of tissue paper and then put it in the chuck. Sometimes it did work, sometimes not, and if it didnt, most of the visible damage came out with a good polish.
This has always been my technique too, although it can be a fine balance between over tightening the chuck and leaving nasty marks, or under tightening it and having the workpiece slip.
Sometimes I use slips of aluminum sheet from beer cans. Gives a nicer grip than paper but still softens the jaws.
