I recently had a question posed to me about condensation forming on the inside of the cap of a demonstrator and how to best address it. This got me to thinking about a related issue which is ink that can get trapped between the outer and inner caps. It is not uncommon for condensation to form inside a cap and the nature of the demonstrator is to make this phenomenon quite noticeable. The science behind the formation of condensation is fundamental and depends on warm air meeting a cool surface. Pens that are kept close to the body, i.e. a shirt pocket, are warmed to body temperature and condensation forms when the outside of the cap cools faster than the air surrounding the nib. This has no effect on the pen’s performance and usually can be easily wiped away with a cotton swab or towel. More troublesome can be ink that works its way between the outer and inner caps which cannot be easily flushed away with a simple soaking.
The remedy for trapped moisture/ink can be the disassembly of the cap which allows the inner cap to be separated and removed to facilitate cleaning. While I do not recommend that this procedure be considered part of routine maintenance, it certainly can be pulled off relatively easily and without any negative consequences. I will describe the procedure below as well as leave you with some thoughts afterwards.