Leaking Kaweco Dia

[Lon_dubh]

Hi all

 

I would like to ask for a repair advice for a leaking ancient Kaweco Dia. The pen hadn't been used for a long time. I flushed it thoroughly and soaked it in water for about 1 day before inking it. Now it seems there's a leak from the threaded part right above the section (see the picture).

 

No idea why this happens. I believe this is a one-piece barrel with the cap thread cut on it, that is, not a separate section piece screwed on the barrel, which would be the usual suspect for a leakage. However, I might be wrong.

 

Any ideas about a possible repair? I was thinking about using PTFE spray meant for waterproofing (NOT the stuff used to lub bicycle chains!): I would mask the rest of the pen and leave just the thread exposed to the spray. Would this work?

Edited August 20, 2017 by Lon_dubh

[siamackz]

All my vintage Dias- 802, 803, 805, are one-piece barrels.

 

So, if it is leaking from the section then it might be a crack? Can you look under a loupe?

[Lon_dubh]

I don't have a strong loupe right now, but I was able to identify the crack: it goes along the bottom groove of the thread, that is, the one closest to the nib.

 

If I hold the section in one hand and the upper part of the barrel in the other, and I *gently* apply force as though trying to bend it (i mean really gently! I don't want to break it), a tiny little ink droplet appears at that thread groove. Obviously the pen shows some flexibility, so when I apply that gentle force, the two parts allow for the crack to go more open or close by a tiny fraction of the millimeter.

 

Now, the question is, how can I glue this, so that I can still use the thread (& screw the cap on). I imagine that simply smearing glue over the thread is not a good solution...

Edited August 21, 2017 by Lon_dubh

[siamackz]

I think one of the pros will need to take care of a crack like that. I wouldn't advise using any glue.

[tmenyc]

No, I'd agree. It needs to be disassembled, the piston removed, and solvent-welded. Once apart, since it has not been used for a long time, it's worth evaluating the cork's condition, too. This is a do-able job, does not require fancy tools, just some care. If the pen is pre-WWII, an MEK-based solvent should work; if post-WWII you'll need something with methylene chloride, like liquid model cement. Just a little, feathered into the crack, to minimize scarring and seal it well. If it's MEK, do take care to not inhale the fumes. Either way, give it a day to cure well before doing anything with the pen.

 

Tim