I have have had my vintage Pelikan 100N restored by a reputable professional which included replacing the worn cork piston seal with twin rubber seals. When I received the pen back from its restoration the piston seal was stuck fast to the inside of the barrel. It spent around two weeks in transit, so though it may be the humidity on the plane. The restorer confirmed the seals are to Pelikan specification.
Under video instruction I was able to the free up and remove the piston and seal and re-apply silicone grease and the seals moved freely when the knob was wound in and out. Within 24 hours the piston movement was showing signs of sticking and into 48 hours it was stuck fast again, so it wasn't flight humidity as a cause.
At this point I have not replace the piston mechanism into the pen for fear of breaking parts in trying to remove it after being stuck fast.
The product I have used is CRC Silicone Grease - Plastic and Rubber Lubricant which states it has a temperature range of -40 deg C to 200 deg C so it will not harden, freeze, dry or melt. A query to the CRC manufacturers confirms it is 100% silicone and is alcohol free.
Has anyone experienced this problem - was there anything special in overcoming it?
Thanks
Innes
Edited by Innes Cate, 28 February 2015 - 09:43 PM.