Good evening folks! Had a very interesting pen come across my work bench, and I would like to share its simple repair with everyone. This will also serve as a maintenance pictorial for the future owner of this pen.
These Waterman Piston fillers were made for the Swiss market sometime in the 1950's, and only for a few years before production ceased. It has two ink view port holes to see ink capacity.
The section is threaded, and will be the first piece to take off. If your section won't unscrew it might be shellaced in. Use some heat, but be careful since celluloid can melt. Go slow! Once the section is out turn the piston knob to deploy the piston rod all the way down, and give it 2-3 extra turns. This will disengage the rod from the turning knob, and don't worry it won't harm the knob since the piston rod has extra room with the section removed for the knob to fully disengage. Once the turning knob is off use something firm and narrow enough to fit inside the barrel. Use this to push the piston rod out of the barrel from front to back getting the piston rod out at the knob end. Sorry the pictures are dark, but you will manage.
2. Lube/Replace piston seal. Lube with Silicone Grease.
For threads on the section, piston rod, and piston knob that threads into the barrel I like to lube the beginning two-three circles of the threads that will engage first. Once you thread these parts in the silicone grease will spread, and coat the threads evenly. I didn't have to replace the seal on this pen since it was still good, so can't give you hands on advice on replacing it, but it should be fairly straight forward since you have the piston rod out. Remember to lube the piston seal whether you need to replace or not on the front and back seal. I used a toothpick to lightly coat the entire circumference.
3. Putting it all back together.
I love how simple this pen is, and its simplicity makes it so easy for maintenance. First screw the section back in. Once you get the section in insert the piston rod from the back of the barrel. Use a firm stick to push it all the way down the barrel until it sits against the section. Which should look like this once its seated.
Now take your piston knob and seat it against the barrel ready to thread back in. Before you thread it back into the barrel it will catch the piston rod first for about a turn or two before the knob will thread into the barrel. This design makes it easy for the piston to be at the perfect length all the time(great design!). I put the knob against the barrel feeling contact with the piston rod, and gave it a turn in the unthreading direction until I feel the threads sit and line up to know I have a positive catch on the threads(great habit to not cross thread anything!), and then I start screwing the knob in. Just screw it all the way in and the piston will be perfect.
4. Enjoy a freshly lubed piston filler with a great Waterman nib(this one has flex, and the figure 8's on the paper is from this very pen!)