I ride to work on an aluminum frame bike. It only has one set of holes for a bottle carrier, on the down tube. I'd like to add a second bottle on the seat tube.

1. Can I simply drill an appropriate sized hole, then force a screw in to create the threads? (That works with steel sometimes) Do the properties of aluminum allow this?

2. Or should I just look for a bottle carrier that attaches via some kind of strap or clamp that wraps around the seat tube...no drilling?