AliExpress PEI pen eyedropper fill results. More photos & writeup in comments.

The AliExpress PEI fountain pen has been successfully eyedroppered.

As it was already inked when the silicone grease arrived, I tried a shortcut (impatient); removed the converter, and removed the section from the barrel. I applied grease to the section —> barrel threads, added a converters worth of ink to the barrel, and reassembled. This seemed to work well, but in my haste I overlooked greasing the nib unit —> section threads, and they filled with ink, although it didn’t fill the grip. The section to barrel union does not leak any ink.

There is a problem with the cap. The way the threads & O-ring are arranged means that a seal remains for a portion of the unscrewing process. I’m assuming this causes a vacuum, and nib leaked a good deal of ink into the cap, I’d imagine because of the more than tripled volume in the barrel over an installed converter. I solved this by removing the cap O-ring from the section. So far this hasn’t caused the nib to dry out, but more time is required to verify this will be a long term fix.

The first attempt with ink from the converter.

The nib due to cap suction.

I tore everything down an gave it a good wash with a drop of dawn liquid. I then greased the section threads and installed in the barrel, and greased the nib unit threads and installed in the section.

This time around I used the black ink from two pilot cartridges. Everything seems OK. No leaking, and the nib unit threads didn’t absorb any ink. I left the cap O-ring out.

Current working state.

If trying this surgery, I’d recommend the following.

1. thoroughly clean everything first.
2. apply grease to the section only (outside threads & inside threads from the barrel end). There is no way to grease the nib unit and slide it into the section without getting some on the inside walls. This temporarily changes the translucency of the PEI. No harm, just doesn’t look great.
3. Remove the cap O-ring or it’ll suck ink from the nib every time the cap is removed.

Hopefully the nib doesn’t dry out long term, because this is exactly what I had envisioned when purchasing this pen.

How's the Schmitt nib? If I remember correctly. Have it in my shopping cart but haven't decided if I want to place order.

I just got mine tonight thanks to nosediv3 as well. Currently inked eyedropper with no grease but only a bit of troublemaker Dona Vittorina (since it's notorious for staining. Schmidt nib is ok but I might look into a flex nib for it.