After being frustrated by the scratchiness of some of the Esterbrook nibs, I decided to swap nibs.
I did this before when I put a 2-tone nib into an Esterbrook for my wife.
I removed the collar (hot water method) and replaced the Esterbrook nib with a Chinese M nib that I got off eBay.
One problem, the Chinese nibs appear to be thinner than the Esterbrook nib, so the collar goes further UP the feed+nib. This did not seem to affect the function. It just made the nib sit further into the section when screwed into the section.
Result, the Chinese nib is MUCH SMOOTHER than the old Esterbrook nibs
I might just replace all my 1xxx and 2xxx F nibs with the Chinese nibs.
Edited by ac12, 27 February 2017 - 08:30.