Parker 21 repair attempt

[azkid]

So I bought a bunch of Parker 21s to see if I could reliably disassemble and reassemble them and address their tendency to be drippy.

Another weird thing is that the sac nipples get squishy over time in some of these pens, or at least the two from 1952 whose sacs I planned to replace.

I attempted repair of one of those pens by cutting off the sac nipple, drilling out the connector, and fabricating a nipple out of Delrin. Below is the section I drilled out and a squishy one.



I surfaced the Delrin rod, drilled it out, then turned it for the sac nibble diameter and to fit snugly in the connector.





I used 5 minute epoxy to adhere the replacement nipple in place. Unfortunately I goofed and the connector split at the end. But the epoxy seems to be holding it together.

I didn't have a small enough boring bar for the connector or I might have avoided this issue that I blame on drilling the flexible connector.

Here are the two connectors, one with the nipple fitted.



Here's the new sac in position.



Once I put things back together using the best parts from two pens, I realized the feed was cracked at the tip. I've broken two feeds already—they seem to be incredibly delicate and brittle.

Keeping in mind that this was a cheap test pen that would otherwise go in the bin and that repair would require parting out yet another pen, I decided to try reinforcing the cracked area with some CA glue. I didn't think it would stick, let alone strengthen the area. But it did. It also strangely affected the texture of the feed material.

I put the pen back together and it writes for now. I wouldn't sell or give it to anyone, as I don't really trust it will hold together over time. But we'll see I guess.

Anyway, I am kind of done with 21s. They're not worth enough to offset how frustrating I find them to work on.

Thoughts, suggestions, constructive criticism welcome.