Early Thick Rods From Sheaffer

July 31, 2011

I thought readers might enjoy seeing photos of a Sheaffer "Vacuum-fil" project I'm working on. The pen is a very early Sheaffer sub-brand "Vacuum-fil" plunger filler (c.1934) with the rare and very early THICK coated plunger rod. These photos illustrate a common problem: the plastic/rubber coating of the plunger rod gets stuck in, or fused into, the extra large packing unit. Fortunately some of these early pens have threaded packing units that can be removed. I did that in this case, and you can see the whole removed threaded packing unit hanging on the the end of the thick coated plunger rod.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4722.jpg

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4719.jpg

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4721.jpg

That packing unit is on tight and cannot be moved without damaging the rod's plastic coating. So I am now soaking the whole thing in a rapido-eze/ammonia/water solution in the hope that something will soften up inside the packing unit. Obviously, when the packing unit cannot be removed, this operation is really difficult!

I plan to use these shots as the first in a progressive description of thick-rod repair.

Cheers,

Gerry Berg

Edited July 31, 2011 by gmberg

July 31, 2011

UPDATE.

UPDATE

Finally got the packing unit off the plastic coated plunger rod. Fortunately, the plastic coating on the rod is unblemished.

In the following pictures you will see (roughly from left to right): the threaded packing unit, the coated thick rod, bits of petrified felt that was inside the packing unit, a whole un-petrified felt ring from another thick-rod packing unit, the hard backing washer, and below it, the closing nut.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4776.jpg

Here's a close up side view of the double threaded packing unit.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4771.jpg

Here are some shots of the inside of the emptied packing unit. You can see a very wide opening for the thick coated rod.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4773.jpghttp://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4770.jpg

This looks into the packing unit end of the barrel. You can see a "floor" made be a piece of plastic that has been swaged (?) into the barrel. The packing unit would screw down tight (counter-clockwise!) onto this floor. What you cannot see are the remnants of the rubber O-ring/washer that lay on the "floor" and formed a tight seal between the floor and the bottom of the packing unit. Judging from these remnants, the original o-ring was the size of the large flexible piston washer with a suitable wide hole in the center for the thick rod.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4780.jpg

August 2, 2011

UPDATE #2

Here are the components of the piston and packing unit ready for assembly. The first pic show the re-packed wide-rod packing unit from the bottom which will face toward the nib as it's screwed into the barrel. Since its internal diameter is about 2 mm wider than the standard threaded packing unit, I have reduced it to fit the standard o-ring and closing washer of white styrene by inserting a white styrene ring around the internal diameter of the unit.

The second pic shows the packing unit from the side. Just above it is the buna-N gasket that will fit between the packing unit and the shelf within the barrel to create a strong seal.

http://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4783.jpghttp://i11.photobucket.com/albums/a152/gmberg/Vac-fil%20THICK%20rod%20repair/IMG_4784.jpg

Gerry