Sealing Cap

[Hans-Gabriel]

I was wondering if a plastic seal in the cap is essential in the design of an aluminum FP.

 

Is it to protect the nib from drying or to prevent a chemical reaction between the ink and the aluminum or both ?

 

If the cap is not supplied with the nib unit, do you have suggestions where to get then ?

 

H-G

[Algester]

if your entirely kitless I think you can fashion the cap out of resin possibly else ebonite but I'm not sure how ebonite and metal and ink work together

[hatchetfish]

An unlined aluminum cap (or any aluminum exposed to ink long-term) would corrode, yes. A second benefit is cap sealing, but isolating the metal from the ink is critical. Kaweco, for instance, use a plastic inner cap and a nib unit with a thread in plastic feed housing in their aluminum pens. Since they're cartridge/converter, the aluminum body, section, and cap are all isolated from ink, with the ink contained by the inner cap, feed housing, and cartridge.

[Hans-Gabriel]

An unlined aluminum cap (or any aluminum exposed to ink long-term) would corrode, yes. A second benefit is cap sealing, but isolating the metal from the ink is critical. Kaweco, for instance, use a plastic inner cap and a nib unit with a thread in plastic feed housing in their aluminum pens. Since they're cartridge/converter, the aluminum body, section, and cap are all isolated from ink, with the ink contained by the inner cap, feed housing, and cartridge.

 

Good info hatchetfish, thank you!