~1936 Large Marine Green VACUUM-FIL

 In 1933 Sheaffer created a sub-brand they called VACUUM-FIL. VACUUM-FIL seems to have been intended for the initial release of the vacuum filler in 1934 as a means to work out the design and manufacturing process. The first Sheaffer Balance with a vacuum filler appeared in the 1935 catalog. VACUUM-FIL renamed the WASP Pen Co in 1936.

This is the largest VACUUM-FIL / WASP pen made; collectors call it OS or Oversize. It may be from the overlap of the VACUUM-FIL vs WASP eras as it has a #6 WASP nib. I have seen other pens with mixed parts that seem to give evidence of a period of transition. The nib is soft, bouncy, wet and an amazing writer. I hesitate to describe it as semi-flex because these nibs are 12 karat gold and quite thin. They provide lovely line variation under normal writing pressure but should never be pushed like a truly flexible nib.

The cap band and clip ball have some pitting to the plating. The peak of the clip has an area of plating loss. The transparent barrel has darkened a bit from its original pale green. The clarity is still amazing. The green portions of the mottled celluloid are transparent though that is difficult to show in photos. It is best seen in the lower area of the cap. This transparency has darkened on the barrel threads and the blind cap. There is one very small pit in the barrel below the manufacturer's imprint.

The original filler rod was celluloid covered carbon steel. Moisture tends to seep under the ends of the cover causing the rod to rust and the cover to split. I have replaced the rod with one I have custom made to the proper length and threading. It is black oxide coated stainless steel that will last decades. The filler seals have been replaced with modern materials that will last decades with an occasional application of 100% pure silicone grease on the filler rod.

Length
Capped - 128 mm (5.1”)
Uncapped - 119 mm (4.7”)
Posted - 150 mm (6”).
Diameter
Cap - 13.3 mm (0.53”)
Barrel - 11.5 mm (0.44”)

Filler
Vacuum-Fil

Nib
fine-medium