Looking through yesterday’s search terms I find “how to disassemble a Mentmore Autoflow”. As it happens, I don’t have an Autoflow but I have a Mentmore Diploma which disassembles in exactly the same way.
Mentmore Autoflows and Diplomas are the epitome of the standard thirties/forties/fifties British pen. Once you’ve taken one of these apart, you’ll find that 75% of other British pens will come apart in the same way.
The section is a friction fit. I was able just to pull this one out with my fingers but mostly they’ll need a little dry heat to loosen them up. Don’t soak the section – it’s black hard rubber and it will fade. Soaking is mostly ineffective anyway.
Ensure you get all pieces of sac out. I use a dental pick to get inside the barrel. Check with an inspection light or torch. I use my trusty pocket knife to scrape the remnants of sac off the section nipple.
It isn’t always necessary to remove the nib and feed from the section. I was able to run water through the section and the nib is perfectly aligned, so I leave it alone.
In a similar way, you usually won’t need to remove the clip screw, but this one has faded to white, so I’ll want to polish it back to a more acceptable colour. The other reason for removing the clip screw is if the clip is bent. Again, no soaking! This is what your friend the heat gun (or hair dryer) is for. Clip screws can have long threads and are often gummed up with dried ink. I trickle a little water into the cap, drain it and clean of the excess ink with q-tips. If necessary, section pliers can be used on the clip screw. Once it’s apart I rinse off the rest of the ink in the cap and clean the threads in the cap and the screw. Q-tips and kitchen towels will do the job.
You’ll want the biggest sac you can put in the barrel without touching the sides; in this case a size 18 sac is correct. I use a pair of dividers with the points ground off as a sac spreader. Allow the shellac to dry and dust with talc or French chalk.
I polished the clip screw until it was dark brown. Taking it all the way back to black would be inappropriate on what is a quite well-worn pen. You might want to polish the nib at this point. Avoid liquid or paste polishes which can dry between the tines and in the section; I use jeweller’s rouge. Polish the plastic and metal trim.
Reassemble and test. That’s it!
Of course, they might have meant an Autoflow button-filler…