Please Help: How To Unscrew Piston System?

[jpk]

Hi,

 

I have got this small German pen marked "*AUGSBURG" (which is a city in Germany) on the clipless cap:

 

It was fitted with a semi flex Bock nib:

 

It has a nice clear ink window (looks slightly too orange on the photos):

 

I need to replace the cork seal but don't know how to get the piston system out of the barrel:

 

The barrel looks slightly thicker at the end, maybe the piston system is pressed into it? I can't move it and am afraid to crack it if using too much force. Do I have to use special tools or heat?

 

Also I don't have any idea regarding identification. Please share your knowledge! Here are some more pics:

 

 

[praxim]

See photo 5, the one that shows the piston knob? Push out the pin you can see in the knob, then unscrew that knob which will separate it from the piston. Now, the theory is that you will be able to unscrew that ring you see at the top of the barrel. Use heat and give it a go. All warranties excluded.

[Ron Z]

....except that not all threads unscrew from the barrel. Some are machined onto the end, and everything has to go out the front. Look VERY carefully between the threads and the edge of the barrel. No seam? It won't unscrew. Even if there is a seam it can be difficult to loosen and get out. If the section comes out, you may be safer taking the piston out from the front.

[siamackz]

Here is the order I would try:

1. Some of the old Kawecos unscrew at the barrel end in order for you to service the piston.

2. If not then I would try to unscrew the section and access from there

 

All the best!

 

Sia

Edited August 3, 2018 by siamackz

[praxim]

Remember to knock that pin out to remove the knob before trying to unscrew the ring.

[Erik Dalton]

Great posting thank you! Please keep us up on how this works out.

[jpk]

Many thanks for the input! I can see a faint gap between the barrel and the part which doesn't come out at the back. I heated it with 65 c-degrees hot water, but it didn't come out. The barrel is slightly thicker where the part sits in it, so maybe it's press fitted and/or glued.

 

I didn't notice at first that the section was a separate part, but I was able to unscrew it with hot water and could take out the piston through the front:

 

Also thanks for the hint about knocking out the small pin

 

I will soak the parts in water and clean them. After that I will try to turn a cork seal on my lathe. Do I have to penetrate the cork with some stuff like oil or wax? Or should I better use rubber instead of cork?

 

I am surprised how well made the parts are, everything looks almost new!

[Ron Z]

Good job in getting it out! I always say that opening the pen is the most dangerous moment.

 

Some use rubber for the seal, but I find that rubber, even well lubricated, tends to stick and bind in the barrel, and it would be rather difficult getting it out with the sealed back end. Go with cork. Lubricate the cork and test the fit working the piston in and out from the front. Once you know that it will work, turn it around and put it in with the mechanism

 

There are differing opinions on what lubricant to use on the cork. Some use paraffin oil, which in the US is clear lamp oil. Most of us use pure silicone grease, and that is what I would recommend. Some soak with paraffin oil and then use the silicone. I don't, and find the silicone to be sufficient.

[Erik Dalton]

Nice job.. I’ve learned a lot from this thread.

When Ron Z gets into a project it’s just amazing to see the facts that come out of his head. Thanks all.

[jpk]

Many thanks for the help! I will try my best and report back as soon as I have access to my tools (I am on tour...)

[jpk]

Happy end: I learned to make cork seals - thanks for your help!

[newlife]

BTW this is a pen manufactured in by Discus in Bonn, the former capital of Germany. They made lots of pens for company promotion. I got some of their pens, one of them with the symbol of Junkers on top of the cap.

https://en.wikipedia.org/wiki/Junkers

Another one with the symbol for BVG Bochumer Verein für Gußstahlfabrikation.

https://de.wikipedia.org/wiki/Bochumer_Verein

No english wiki entry here, scroll down a little for a view of the trademark. I have an Augsburg pen too, but I don't know if it was a promotional item for the german town by the same name. Discus surely focused on this kind of pocket pen and made lots of them, mostly with DISCUS BONN engraved on the cap. Most of them feature a piston system, but there's a button filler among my pens too. Quite astonishing to see a pen as short like this as a button filler.

 

Greetings from Germany - Klaus

Edited October 16, 2018 by newlife