TLDR; I managed to repair the cap of my LAMY Al Star.



Few days ago, I posted about my LAMY Al Star breaking around the rivet (?) part, and I recieved a lot of interesting comments, so thank you for that.

After spending a little bit more time to analyze what happened, I realized that the rivet part was, in fact, not broken, but the manufacturer probably didn't push enough on the inside and the ouside part of the rivet which resulted into the top part popping off the cap. The reason I'm sure it's what happened is because I tried to assemble back the plastic and brass parts and when I pushed them together, they just sealed and it was impossible to separate them, which wouldn't be possible if they already broke. 

Anyway, I wanted to share how I managed to repair my fountain pen so anyone with the same issue could do the same. 

  
The tools I used :

* A chicago screw
* A file (20mm)
* A flathead screwdriver
* Something like a chopstick thin enough to push the rivet from the inside
* *(recommended)* A silicone or nitrile seal 
* *(recommanded)* Some pliers
* *(recommanded)* Painter tape

Informations :

* The chicago screws are in two parts : the screw part (male) and another part (female). Depending on the chigago screw you buy, the flat screw head is either on the male part, the female part, or both.
* The inside part of the rivet goes inside a 6.8mm diameter cylinder inside the cap itself. It's important not to force the rivet you will build if it resists. 
* Picture 5 shows what you should obtain once you filed it (on the bottom left), in comparison to a new female chicago screw part (on the bottom right).
* I personally used a rubber seal to make sure the screw stays in place since everything is metal and can easily unscrew with vibrations, but you can used anything that you prevet the screw to unscrew or even skip this part.
* Depending on how precisely the chicago screw has been manufactured, the male part could look a little bit shifted from the center, which is my case. I don't mind it but if it bothers you, you should be informed. 

The steps :

1.  Put some tape around the cylinder zone of the female part of the chicago screw. This is made so you can use the pliers to maintain with the right angle the chicago screw while you file it.
2. You have to file the head the **female part** since it is this part that will go **inside** the cap. The diameter of the female part head should be, from what I measured, under 6.8mm **BUT** you basically have to lime until the female part goes **without forcing** inside the cap.
3. Once you filed the female part so it goes without forcing into the cap center part, remove the tape around the cylinder and push it with the chopstick or anything **so you can see the threaded part of the rivert from the top of the cap** (cf picture 3).
4. Put the silicone/nitrile seal in place around the screw of the male part and screw the male and female part while pushing the female part with the chopstick.
5. Use a flat head screwdriver to make sure the screw is in place while you still push the female part with the chopstick from the inside of the cap. 
6. You're done and your LAMY should be repaired :)

  
If you have any question, don't hesitate to ask me in the comments. 





UPDATE : Confused on what happened here