The Later Duofolds - adapted from the original Parker manual by Peter Twydle.
The later Duofolds comprise: The Maxima Duofold, The Senior Duofold, The Victory V, The Slimfold, The Demi Duofold, The New Duofold, The French "Lady" pen (proportionally smaller than the Slimfold.)
All these models are of similar design and vary only in size, so the descriptions given are applicable to each.
NIB - 14ct gold, tipped with a special alloy to give smooth writing and long wear. Each model comes in eight grades.
FEED - basically the same design as the earlier Duofolds, and made from the same material. It is similar to a Vacumatic feed because it is fitted with a plastic breather tube.
GUARD - generally made from nickel silver, but may be of stainless steel or phosphor-bronze chrome plated. It extends approximately half way along the Pli-glass reservoir. An additional shoulder has been provided on the section for this part. As well as protecting the reservoir, the guard also provides a base against which the pressure bar depresses the reservoir during filling. Filling instructions are engraved on the guard.
PRESSURE BAR - generally made from stainless steel, but may be of phosphor-bronze chrome-plated. One side is spot-welded to the inside of he guard. It extends right around the reservoir.
RESERVOIR- almost identical to that fitted in the Aerometric '51'. It is made from Pli-glass and is translucent. It is also resistant to hardening when using ordinary writing inks.
OUTER CAP - of similar design to earlier models. A machine ridge inside the cap forms a hermetic seal when it is screwed on to the pen. The Arrow clip is fitted by means of a brass bushing and plastic clip screw.
The material from which the cap, barrel, section and clip screw is made is called Plexi-glas.
Method of filling
Unscrew the barrel from the section. Fully immerse the nib in the ink and depress the ribbed pressure bar at least five times. Each depression of the bar ejects air from the reservoir through the breather tube. When released, ink is drawn into the reservoir through the wide channel of the feed.
Method of disassembly
Unscrew the barrel. Empty the pen of any ink.
The next step is to remove the guard from the section. Heat the guard carefully over a small flame just below the section threads. Take care not to overheat otherwise you may damage the threads. Holding the section in the left hand, and using a rubber friction grip, twist and pull off the guard. Do not wiggle it to get it off. If it won't come away easily apply a little more heat and try again. It should be possible to remove the guard without force if sufficient heat is applied.
Note: Unless a visual inspection reveals some form of damage or distortion of the reservoir or guard, the guard assembly should not be removed from the section. A satisfactory press-fit of the guard to the section cannot be obtained after repeated disassembly and assembly
To remove the nib and feed, grip them with Bernard pliers and twist gently to draw out of the section. GREAT CARE SHOULD BE TAKEN DURING THIS OPERATION AS IT IS POSSIBLE TO DISTORT THE NIB.
Method of assembly
Carefully inspect each part before assembly to avoid fitting any that may be defective. Inspect the feed and open the capillary channels with a fine spacing steel. With a flat brush clean all dirt from the feed and check that it is not broken or chipped. Insert the breather tube into the back end of the feed. If a feed is distorted it can be restored to its original contour by heating over an alcohol burner. Inspect the nib carefully for cracks and buckles, making certain that the tip is not porous, cracked or chipped. Examine the barrel, cap assembly and section for damage. See that the vent holes in the cap and barrel end are clear. Inspect the guard and pressure bar assembly for possible distortion. Make sure the pressure bar is in correct alignment, otherwise it may distort the reservoir. If it is out of alignment it is quite easy to adjust it by holding both sides of the bar between the thumb and forefinger and carefully easing it in the appropriate direction.
To fit the nib and feed into the section, align them so that the slit in the nib bisects the tip of the feed. Make sure that the feed lies level in the nib (see: Tuning a fountain pen). After alignment, press the nib and feed into the section with Bernard pliers and check that they are sufficiently tight in the section. Check that their extension beyond the section is correct with a nib fitting gauge.
To assemble the guard to the section apply a small amount of cement to the ribbed shoulder of the section above the reservoir nipple. Insert the assembled nib, feed and section into the assembly block and place the guard over the reservoir. Place the guard support tool over the pressure bar so that it rests on top of the guard, at the same time making certain that the guard is aligned correctly with the section. Holding the guard support firmly give it a few light taps with a plastic or leather-covered hammer to force the guard down the shoulder of the section. Continue tapping it gently until the guard fits snugly against the section threads. Clean off surplus cement from around the base of the guard.
The pen is now ready for nib spacing and final adjustment (see: Tuning a fountain pen)
Note: The Slimfold and Lady models have an additional part called a 'flow rod' which is inserted loosely into the reservoir when the pen is assembled. Its function is to break down surface tension, which tends to hold the ink in suspension within the reservoir. When servicing Slimfold and Lady pens, make sure you return the flow rod to the reservoir before refitting the nib and feed. Flow rods are not fitted to any of the other Duofold pens.
The Lady Duofold
The Lady Duofold is the smallest of the Duofolds and differs from them in that it has a hooded nib. It fills in the same way, and contains a flow rod.
On dismantling the pen you will see a change of feed design, the feed having an air transfer hole to allow air to enter the pen by means of the air channel in the feed itself. The capillary holding space situated between the feed and shell takes the place of the ladder cuts on the side of the normal type feed.
To remove the shell, insert the guard end into the Universal Wrench with the correct collett, as you would into a barrel, and grasp the threads with the wrench. Grip the shell with rubber-covered section pliers and twist anti-clockwise. You may need to heat the shell carefully over an alcohol flame to make it easier to remove, taking care not to over-heat. Nib and feed can then be removed by gently easing from the nipple assembly.
To re-assemble, take the nipple, complete with pli-glass reservoir in one hand, and the guard assembly in the other. Push together until finger tight. Then insert the rear end of the guard assembly into the guard support using a small ring adapter, allowing the rear end of the guard to rest firmly on the adapter ring. Hold in place and gently but firmly tap the nipple assembly home with a small wooden mallet. The reservoir should then be stroked up to ensure it fully fills the space formed by the ribbed pressure bar.
Next, screw on the shell until finger tight. Note the position of the shell tip in relation to the line of the pen. Mark the guard or nipple at the point in line with the tip of the shell. Remove the shell and fit the nib and feed as with the other Duofolds, lining them up with your mark.
Heat down the nib and feed tip. Inspect for correct setting then screw on the shell using a rubber solution for sealing purposes and check that the tip of the shell is lightly resting on the nib's upper surface.