|Filling Instructions: Twist-Fillers|
Most early twist-fillers, such as the A. A. Waterman pen shown above, use a rubber tube rather than a conventional sac. The tube is attached internally to the filling knob at the end of the barrel, which when turned, wrings it out. To fill, turn the knob, put the nib in ink, release the knob, and count to ten to allow the sac to inflate. How far you turn the knob is a bit of a judgment call -- far enough to wring out the sac, but not so far as to rip it loose. In some cases there may be too much friction for the end knob to return on its own, so you will have to return the knob to its original position manually.
It is important to take note if there is a little arrow imprinted on a twist-filler's filling knob, for in many cases (A. A. Waterman pens included) the filler shaft has a left-hand thread and the knob must be turned clockwise. Turning it counterclockwise -- the normal direction for piston-fillers and pens with blind caps -- will only jam the knob, and if forced, could easily shatter the pen. When in doubt, try gentle torsion in first one direction, then the other -- but start clockwise.
The Swan Leverless and the Security fill in the same manner, though their internal mechanisms are completely different. The Leverless uses a longitudinal entangling bar and a conventional sac, a solution that is both robust and easily serviced. The Leverless end knob must be returned to its original position manually when filling. The Security uses a more complex and delicate mechanism, in which a rigid pressure bar moves laterally within the barrel.