Piston-filled pens, with a filling system that has grown in popularity in recent years, come in all kinds of flavors but in two basic types: the single-seal and multiple-seal varieties. The single-seal pens have a screw-gear mechanism that advances to push out air and retracts to pull in ink. These are common in both vintage and modern continental European models and a few vintage American makes, such as Conklin.
While some pen collectors deny that pens with a piston converter are "real" pens, the converter is the most recent rendition of a filling system that goes back almost 100 years. Aware of a move in appeal towards "real" piston fillers, several pen makers have installed a non-removable converter inside the barrel of large pens to give the impression of a fully integrated piston-filler unit. Multiple-seal pistons use a piston rod to drive out air on the down stroke and, in turn, draw in ink via the vacuum in the barrel. Onoto and Sheaffer made this type of filler, and Visconti offers the recent high- powered vacuum filler.
OMAS began making a multiple-seal filler system in the mid-1930s and, after the war, changed to a single-seal filler. The one I was working on here was probably made in the 1950s. The filler unit in all single-seal piston fillers can be removed, although in a few makes -- such as the Conklin -- once installed, these filler units were not intended to come out again. Whenever possible, it's usually easier to remove the piston shaft from the section end of the pen than to take out the entire filler unit. This isn't possible in these early OMAS pistons, because the barrel narrows in the area into which the section screws. Since no part of the filler unit is exposed to the surface of the barrel, the only way to remove the filler unit is to drive out the pin that holds the turning knob to the piston shaft gear.
I use a pin-removal tool to extract the filler knob pin. For pen collectors who remove a pin once in a while, it's hardly worth the bother to find a watch-bracelet pin-removal tool and modify it for pens -- it's far easier to find a drill bit of the correct size, a piece of wood with an appropriate slot to hold the pen in place, and drill a hole in the wood to knock the pin through.
The source of pin problems comes from the frequent use of a metal jacket encased inside the turning knob in order to provide it with greater structural strength. As a result of corrosion between the pin and the metal jacket, significant force is often necessary to drive out the pin. Pin heads tend to be sharp because they are cut off rather than made to size.
Hence it's all too easy for the drill bit to slide off the pinhead and crack or break the turning knob. With patience and repeated light taps of a hammer, any pin will eventually come loose. I do enough pin removals to warrant the pen-pin-removal tool. It provides more precise control over the amount of pressure I can generate on a pin -- and it's fun to find the right tool for the job.
Once the filler knob is removed, the filler unit screws out. Then you can replace the seal with new cork and put everything back together. A note about piston seals: Celluloid tends to shrink as it ages and this change in size is rarely uniform because of the composition of the material and the structure of the pen. For example, the area closest to the section is likely to maintain its original size, while further back there could be several variations in ink-chamber size.
In a production line of pens that all began with exactly the same inside barrel diameter, 50 years later, there will be a wide range of differences. So, unfortunately, it's not possible to stamp out a bunch of seals and use them as the occasion arises. Some will be too large; others too small; and a few will fit. I make seal blanks for piston pens and then machine each seal to match the pen.
Also, it's unwise to use a rubber seal in a piston pen. Cork is several times more flexible and much less sticky than rubber. A rubber seal that fits one part of a barrel may be far too tight and sticky for another part. If a rubber seal gets stuck, sometimes the only remedy is to drill out the seal holder to remove it. When piston designers changed material from cork to plastic, they realized that a straight cylinder seal was too rigid to serve as a good seal. Single or multiple rings were incorporated to these plastic seals to serve as the sealing component.
Rubber can be an excellent seal material in the appropriate application. The Sheaffer Snorkel is good example of a multiple-seal pen. The touchdown tube uses air to compress the sac that draws in ink. The most ingenious part of the Snorkel is that it moves the reservoir to the ink. Cork is too bulky for such a plethora of moving parts and thin rubber seals provide an excellent material for these applications. In the section is a seal for the snorkel tube as it moves back and forth; an O-ring in the barrel for the touchdown tube; and a seal in the end cap plugs up the touchdown tube. The blow-up image shows all the parts of the snorkel, except for the seal inside the blind cap.
The most difficult job in restoring a snorkel is removing the sac-nipple plug inside the sac-protecting tube that also doubles as the snorkel-gear carrier. It's all too easy to be deceived by the crimped-over tube flanges, which look like the main impediment to removing the plug. While the flanges do keep the plug in place and need to be straightened out; it's usually a petrified sac that firmly anchors the plug.
In a snorkel with a pliable sac, an appropriate-sized rod introduced through the hole at the closed end of the tube will push the plug out. With a petrified sac, I begin by using a lot of heat to soften the sac, and then push the plug out. If this method fails, then I introduce a pick with a short, right-angled head, scraping away as much of the sac from the nipple area as possible. A further application of heat, coupled with repeated use of the rod against the perimeter of the plug, will usually pop the plug out.
Sometimes, rust will cause the screw that holds the blind cap to the touchdown tube to seize. Scraping it with a screwdriver will usually remove enough rust to engage the bit in the screw slot. Once in a while, it's necessary to drill the screw out. Put everything back together and test the pen. If it won't fill and all the seals are well lubricated and in good working order, there is probably a crack in the barrel end around the O-ring. Also, inlaid nibs can leak ink along the inlaid areas. Both of these problems can be remedied.
A basic rule applies to fountain pens: Ink and air need to remain in their designated places. Anything that violates this rule results in a pen that doesn't fill, won't write, or leaks ink. Some modern pens violate this rule; some of the pens I see, for instance, lack an airtight inner cap. The pen's cap doesn't need to be airtight, but the inner cap does or the pen won't write when it's uncapped. Once the ink in the feed has evaporated, the nib has nothing to write with.
For instance, the Visconti Van Gogh cap, because of sloppy production, often has a hole in the inner cap that vents out. Holes typically range from pin-sized to 3-4 mm in size. By the luck of the draw, it's possible to find a Van Gogh without a hole, and the nib will write when the pen is uncapped.
The Montegrappa Harmony has a similar problem related
to poor design. As long as that hole is there, the nib can dry out. There
is a 2 mm hex screw inside the cap. All the cap components can be removed
once the screw is removed. I used a small cork plug and epoxy to close
the hole. Returning a Harmony to the distributor or manufacturer will
not solve the problem, since all the inner caps contain a hole. The solution
for both these makes of pens is to plug the holes and restore the separation
between air and ink.