Kaweco Sport V16 Piston Repair

[BCastle]

I have picked up a natty little 1970 Kaweco Sport V16 fountain pen and ballpoint set (photo FP below - in need of a clean-up). The fountain pen has a very nice OB 14ct nib. Unfortunately the piston is well and truly lodged in the barrel (dried ink, methinks), so it is in for a good soak right right now and I've used a rubber bulb to get a bit of water through the nib unit into the barrel.

 

I'd like to remove the piston unit which, from reading threads on FPN, looks to be a simple screw in job from below the trim ring. What I've not been able to work out is which way the thing unscrews - it it a traditional right had thread (clockwise to tighten, anti-clockwise to unscrew)?

 

I'd be grateful for any help and advice.

 

Thanks

 

 

 

[whych]

Don't force the piston.

Throw the whole pen into a dish of water and let it soak - if you have a U/S cleaner, cycle it.

Try and get water into the barrel which should loosen the piston.

Another way of getting water into the pen is by putting the pen nib up into a plastic coke bottle with enough water to cover the nib.

Cap the bottle and then squeeze the bottle to get water into the pen.

 

There is a thread on the Pelikan part (I think) by TorPelikan with pictures of this method.

 

You may be lucky after a good soak to be able to unscrew the piston, but don't worry if you can't. Just keep soaking the pen and work the piston while the pen is submersed and you will get rid of any ink at the back of the piston.

Edited August 20, 2015 by whych

[dneal]

For the V16, you need a wrench to get the piston filler out. Look closely at the threaded portion and you'll see two flat sides. You will have to grind a small ignition wrench thin enough to get in there, or fabricate one. I used a feeler gauge (one of the thickest on the set) and cut a corresponding notch into it.

 

Note that the trim ring is not affixed, and you can move it toward the cap or toward the barrel for easier access to the flat portions of the piston mechanism.

[whych]

This works for full size models.

The Sports are different. You move the ring part. and you will see the flat edges.

You will need a thin spanner or an old computer backplate to fit in.

Edited August 20, 2015 by whych

[BCastle]

Brilliant, thanks to you both for all this help. I will continue to soak and then try to work the piston. I see the flat edges. To unscrew - is at a counter clockwise turn (traditional right hand thread)?

Edited August 20, 2015 by BCastle

[BCastle]

As for a suitable tool, I have a TWSBI wrench one end of which can be filed a bit wider to fit

[BCastle]

Worked a treat (but with a twist)!

 

Soaked but when gently worked, rather than budge the piston seal, the blind cap twisted right off - not a problem as thankfully the seal end of the the inner spindle had moved up out of its retaining slot. With the blind cap off, some low heat and a slight nudge counter-clockwise (it is a standard right hand thread) with my widened TWSBI wrench the piston mechanism easily unscrewed and came away nicely. Now its leaving all bits to dry, a good clean up and a tad of silicone and it will be time to apply ink.

 

Cheers again

 

Bob...

 

 

[whych]

Leave the front end to soak. It usually collects a lot of ink in the feed and its channels.

You can push the nib and feed out from the top of a barrel - use a blunt ended wooden skewer stick.

[BCastle]

OK, noted, thanks again. I'll put the front end back into soak and see how I get on. It's also good to know about the method of easing out the nib and feed.

[rockydoggy]

Really instructive thread--thanks.

And those pens are great writers. I need to remember to use mine more.

[dneal]

This works for full size models.

The Sports are different. You move the ring part. and you will see the flat edges.

You will need a thin spanner or an old computer backplate to fit in.

 

Not sure what you're replying to with "this works for full size models".

 

For the Sports, the V16 is the only one that needs a wrench to remove the piston. The V12 and older (12's, 11's, 612's, 712's etc...) have a removable blind cap, and the piston mechanism is grabbed with some section pliers.

[BCastle]

Not sure what you're replying to with "this works for full size models".

 

For the Sports, the V16 is the only one that needs a wrench to remove the piston. The V12 and older (12's, 11's, 612's, 712's etc...) have a removable blind cap, and the piston mechanism is grabbed with some section pliers.

Yes, indeed. When I first got this pen I thought it would be like my Tropen Scholar with a removable blind cap and twist knob activated piston ( with the most wonderful steel fine flex nib, by the way!). But, the help given in this thread set me straight a put me on the true path!

What a great resource this forum is.

Best

Bob

[Chrissy]

Can someone please advise exactly what size gap is required in the piston wrench tool?

[BCastle]

Hi Chrissy

I used a double ended TWSBI wrench from a Mini and ground one end with a Dremel to fit the Kaweco. I widened the opening from the original 7.06mm to 8 mm (+/- a gnats) - all measurements have been made on a cheap ebay Chinese Vernier Calliper so grind a bit at a time and test fit. I also used the Dremel to reduce the thickness of one end the tool as it was too tight a fit in the opening left by the blind cap.

Hope that helps

Rob

[Chrissy]

Thank you Rob.

 

We found a thin piece of metal and some dividers to measure the gap. The we've cut a slot in this thin piece of metal to make our own wrench. It was such a good feeling when the slot was exactly the right size and I felt the piston threads eventually give then unscrew.

 

I now have a nicely lubricated piston, and a clean nib and feed. All working fine.

[hari317]

This thread was immensely helpful. Thanks to all the contributors.

My pen is a V16 with a 14k OB nib. The piston was seized and the knob simply backed out. Leaving the connector and the spindle nut in the pen. I fashioned a wrench using a 0.8mm thick FR4 sheet. The gap between flats was approx 7.7mm. A little heat and the connector smoothly unscrews with the tool. On my pen, the trim ring remained attached to the barrel.

 

Some pics of the filler

 

 

 

 

The piston spindle has a round area just below the seal. This makes the stroke adjustment slightly tricky. I found that the piston makes a full stroke with just three full turns of the knob. So the method I used was to assemble the spindle nut into the connector and thread the knob fully over the connector. Then back the knob off by exactly 3 turns. Now introduce the piston shaft through the anti rotation slot. The piston shaft threads will engage the spindle nut threads. Now thread the knob in fully, piston will retract into connector. Now again back off the knob, engage your tool to the slots/flats and thread the filler into the barrel.

 

I got an ink capacity of approx 0.65ml.

 

HTH

 

Hari

Edited December 8, 2017 by hari317

[majorworks]

A little thread necrophilia... thanks, Hari, for the details and great photos of the innards of a V16 Sport. I just acquired one from the auction site (my second). This one's a V16N with OB steel nib. It doesn't fill as well as it ought to, but enough to write with for now. At some point, I'll want to remove the piston mechanism, have a look at it, grease it up, etc. So this thread will definitely be a resource for that.

 

Apropos of nothing... the seller said the pen had a 14k nib, but conveniently did not show the model designation on the barrel in any of the photos. My bad for not confirming that. The listing also did not mention the nib size, and I did ask that question. The answer was that it was a semiflex M nib. Wrong on both counts. Gotta love buying online.

[whych]

The model number and nib grade are stamped into the barrel near the piston knob.

Look at the pic in post #7.

[majorworks]

The model number and nib grade are stamped into the barrel near the piston knob.

Look at the pic in post #7.

 

Thanks... yes, I know that. I was saying that the seller did not display that part of the barrel in his photos, thereby making it difficult for me to ascertain that the pen was a V16N (steel nib) until I had it in my grubby hands.

[saskia_madding]

Guys - do you know anywhere I can buy a tool that will fit the Kaweco v16? I just got one with a REALLY tight piston, and I don't like the idea of endlessly forcing it whenever I use it. I deifnitely need to take it apart and clean and relube it.

But where can I get a tool to open the back? I don't have a Dremel to modify a pre-existing TWSBI tool.