Resealing Sheaffer Vac-Fills
From Penpedia
There are several known methods of resealing worn out Sheaffer Vac-Fills. Some are better or easier than others, while some are "purer." There is little consensus yet as to whether after market additional sealing elements should be used, or if it harms the provenance of the pen.
Items in picture at right:
1,2,3: "Twin punching tools" for the three Vac-fill diameters Sheaffer made.
4: The extractor tool to allow pulling of approx. 70% of old packing assemblies.
Note there are two extractor spindles with different mating threads and three back-up
rings so one has the maximum back-up surface against the barrel end.
5: A stainless screw driver knob allowing easy removal of the blind cap enclosure screw and for tightening the seal enclosure screw of the "full replacement" fountainbel cartridges.
6: A cleaning pin to remove the inner hole cuttings out off the inner punches.
7: A hollow drill to allow the drilling out of stubborn, old rod packing assemblies (made in
the three sizes).
Note the gray nylon "centering" bushing and the thin walled black bushing sticking out a little. The bushings provide a perfect centering of the hollow drill during the manual drilling operation.
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[edit] The Fountainbel Cartridge
The Fountainbel Cartridge is a newer entry into the field, allowing a supplementary seal to be installed into the pen without harming it. Two basic versions are available : 1- The "full replacement" version which replaces the original rod packing assembly (after it is extracted from the barrel) 2- The "additional" version which is complementary installed in the barrel without the need of removing old packing units.( technical sound alternative for the "add a rubber plug" approach ) Cartridges for both open nib and Triumph nibbed pens which have integrated or separate ink chambers are available . Some ink volume is lost as a trade off of this method. The installation of the cartridge is fairly simple, and is not expensive. Fountain Pen Network user fountainbel, based out of Belgium, will also perform the installation at request.
[edit] Install a complementary sealing plug in the barrel
It is the opinion of some that this approach is not acceptable.
The "add a sealing plug" method carries the risk of cracking the barrel if the plug fit is to tight. On the other side, gluing the sealing plug in place may be destructive, making its future replacement very difficult or even impossible! A further draw back is the inherent need for the delicate dis-assembling of Triumph nib assemblies to allow installation of the extra sealing plug from the section side.
The extended sealing contact and rubbing friction between the plunger rod and the plug will not only wear out the sealing plug rather fast, but will also considerably increase the filling actuation force. This approach also complicates future maintenance to replace piston and plunger rod seals.
This approach is, at best, only a doubtful and temporary solution, as already experienced by several collectors.
[edit] Re-stack the sealing unit with new seals & felts as original
This can be considered the ideal and pure approach. There is however a drawback on this approach: The rubber rod sealing rings have to be tight on both the rod and on their outside diameter to obtain a leak free system. This implies the outside and inside diameter both need to be perfect in diameter and concentric to each other.
Assuming one succeeds making and installing these perfect seals, they should work fine initially. The axial pretension of the stacked battery of rubber seals and felts is however very low. By pushing the plunger down one creates a vacuum which, in combination with the friction of the seal on the rod, is pulling the rubber seal around the rod gradually towards the ink chamber. This friction is strongly reinforced when the initial silicone grease is gone and the rod/ seal contact surface is not greased properly. In the end, this results in leakage, not just over the rod sealing lip, but also over the external diameter of the seal.
This was proven by tests ran by FPN user fountainbel where he installed a small 20 mm stroke pneumatic piston connected with the plunger rod and simulated a repetitive filling stroke for 2 hours at a rate of 1 stroke per second. This is approximately 7200 filling strokes. It was clearly visible that the seals were somewhat "extruded" towards the vacuum chamber, resulting in leakage over their outside diameter. This phenomenon has also been seen on rubber seals of the worn original sealing units. This might have been an excessive test, and he did not test when the leakage started, but it did reveal a potential longer term risk.
[edit] Drill out the existing sealing elements and install an O-ring in the old packing unit
Drill out the old packing unit from the section side and install an O-ring fitting tight both around the rod and the in the packing seat. The O-ring locked axially and kept in place with a glued in back-up ring. This approach was possibly pioneered by Vintagepens.com, and is one of the most technically sound solutions.
A draw back is the inherent need for the delicate disassembling of the Triumph nib assembly and the drilling-out operation of the old packing seat to allow installation of the new sealing element from the section side. One also has to glue a back-up ring to keep the O ring in place, which is rather delicate given the risk the glue may also stick to the barrel wall. And since installation occurs from the section side, this approach endangers future maintenance to replace piston and plunger rod seals. Replacing a worn O-ring down the road means again disassembling the Triumph nib and renewed drilling out of the back-up ring from the section side. There is also no "enclosed" silicone grease reserve provided, meaning that one should regularly apply some silicone grease on the plunger rod to avoid "dry run" problems which leads to excessive actuating force and premature wear of the O-ring seal.
USING THE “FOUNTAINBEL” TRIUMPH NIB REMOVAL TOOL (version061008) Sheaffer used 2 different cone angles over the time the Triumph nib was used. The initially used “less steep” cone was used on 75% of the pens, the later introduced “steep cone “can be used on approximately 25% of the pens. This implies there are also 2 tools available. Using the tool with the “less steep” cone on pens with a “steeper “cone nib may work, but the risks of cracking the feed during clamping are considerable. The tool consists of 3 parts, the ring, the key & the clamping screw. The ring, made from Ketron-Peek - a heat resistant hard plastic -.features a conical bore fitting on the conical nib. A key groove in the bore holds a high stainless steel key- introduced at the smaller end of the conical bore. This tooth fits perfectly in the axial groove at the back of the HR feed. Aiming for maximum support on the feed, the teeth features a thin finger which goes underneath the backside of the nib ring After introducing the key finger in the axial groove of the feed & underneath the nib ring one moderately presses the pen in the tool cone. After clamping the key -by tightening the screw firmly by hand only- I start to heat up the section end. I use a Steinel HL1910 heat gun on stand 2.5 .Temp graduation 1 t o 9, Stand 2.5 is around 120°C. (temp range being 50° at stand 1, and 630°C at stand 9 ). On the head gun I mount a blowing mouth of 10mm diameter & rotate the pen (in the tool) on a distance of 2.5 to 3 cm (1"-11/4") from the blowing mouth. I go "by feel & experience" and use my lips/ tongue to sense the temperature of the section end. Heating up takes approximately 40 seconds. I heat up as high till I can just keep my lips against the section. It takes me 1 minute to remove a nib assembly. Note our lips/ tongue are very sensible to temperature variations & are in my opinion the most efficient tool to determine the length of heating cycle On 29 of all 31 pens I've tested the complete nib assembly, being nib, feed & the plastic bushing came out together. The nib assembly fits rather tight in the tool cone, as stated before one should not press the nib to firm in the tool. This is one (small)drawback on applying the perfect fitting cone: the nib fits really tight in the seat, so you should not really" press" the nib in the ring seat. Just push the nib slightly in the seat, otherwise nib removal becomes difficult. Providing more grip for removal & avoiding an over tight fit is in fact the reason why I left part of the nib ring sticking outside the tool ring. Installing the silicone rubber washer(s) on the exposed part copes with the risks of undesired heating up of the exposed nib part Removal out of the seat goes best by wiggling the nib unit a little
The tool guarantees the whole assembly will come out, since the nib & feed are positively clamped together- radially secured by the key - prior to starting rotating the tool. This implies nib & feed can't rotate versus each other during the screw out operation. Advantage being that the cylindrical tail of the feed - fitting rather tightly in the threaded bushing -ensures that the loosening torque of the threaded bushing in the section is considerably lower as the loosening torque of the nib alone. In other words, the friction torque of the cylindrical feed tail in the bushing creates a complementary friction torque, which is supporting loosening the thread fit of the threaded bushing in the section. Note I broke one feed on one of the first pens due to over tightening and /or by starting to rotate the tool before the loosening temperature was reached As usual with delicate operations, there surely is a learning curve, but I assure you from experience, this is the silver bullet! The attached pictures show the progressive numbered steps in disassembling the nib.
1-Align key: The key finger is laterally positioned so it can go under the nib. Once this position is set it works on 90% of the nibs my experience.- or only a minor correction is necessary 2- Align key in feed groove : The pen is introduced so the feed groove can slide in the key & underneath the nib ring. 3- Push pen in seat: Now push the pen with moderate force in the seat. 4- Clamp key: Tighten the clamping screw firmly- BY HAND - never use an Allen key to do so or the feed may break! 5- Heat-up: while rotating the tool, feel regularly with your lips tongue if the temperature in reached.. Avoid heating up the exposed nib ring (see 2 below) In my experience you should be just able to hold your tongue on the section once the desired temperature is reached. 6-Screw nib assembly out: Don't force it, rotating the tool ring the nib should come out applying a moderate torque. Heat up again when deemed necessary
Some additional advice : 1-I recommend to use Ron Zorn original Sheaffer sealant for sealing the threaded bushing in the section, while using shellac for mounting the nib on the bushing The loosening temperature for Ron's sealant being lower, the shellac will still hold firmly when Ron's sealant is already soft. This further reduces the risk the nib will loose first at a later repair. 2- Given small length & diameter variations between Triumph nibs, a part of the nib remains visible. During heat-up one should avoid heating the nib, since the gold heats-up faster as the celluloid. Eliminating this risk on nibs which are protruding 2-3mm, one or two of the included silicone rubber washers are installed over the section avoiding undesired exposure of the nib ring during heat-up , hence avoiding risks of loosening the nib/bushing sealant fit. 3-Note the tool ring can also be used to drill out the broken bushing parts on the lathe : push the nib in the cone , clamp the ring in the chuck , install a 7mm diameter drill in the tail stock & drill 3mm deep. The remaining plastic thread wires in the nib thread can be removed with a small triangle scraper or a needle.
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