Osmia Supra 74 ED conversion

[fdabao]

For the curious and maybe that one other person in the world who faces a similar problem to mine......

 

 

This pen is my favorite for writing, by far. It's very unremarkable in appearance but the ergonomics are perfect: nib flexes well, ink flows smoothly, the chasing gives it a really good grip, and it's just so light and well-balanced.

So when the old O-ring gave out, I really wanted to restore it. But when I opened it, I found that the plunger part had also splintered a little.

It's hard to describe (and I don't have good pictures) but basically the screw mechanism which is used to push-and-retract the plunger, couldn't function properly anymore due to the splintered part.

 

Quick internet (ebay) search told me that there was almost zero chance of getting my hands on a suitable replacement parts, not for a price less than simply buying a new pen. I can replace O-rings but I can't fix broken plungers.

 

Since I actually like eyedropper better than any other mechanism, ED conversion was the obvious solution. Only problem was, most of the online guides on how to convert piston fillers to EDs are for pens that unscrew at the section-barrel junction - which makes it a pretty simple matter to fill up the barrel with ink, you only have to worry about sealing it.

With the Supra design the section and barrel are fused into one continuous unit. The only part that can be removed (apart from the nib) is the plunger, after uncapping the rear. Obviously, you cannot fill the pen from the rear - the ink will simply gush out of the feed.

 

Solution: immerse the whole uncapped barrel in a test tube full of ink (dropping more ink into the barrel if necessary - you want to have minimal air inside). Insert the plunger (with new O-ring) and push all the way and screw it in. Messy (then again it's an ED), but it gets the job done!

 

And for some reason, the pen never burps or leaks. It functions just as well as it did as a piston filler. It even seems to hold more ink than was possible with piston filling. The only typical ED issue I've encountered is when it hasn't been used for more than a day, or if I somehow leave it exposed, then it will dry and require a hard start. I just shake it a bit until I see the ink oozing out the feed (or drops start falling) and problem is solved.