Friday, April 18, 2014

Problematic Pistons

On Monday I shared a pic of a piston filler suffering a little seepage where it should not, and given the resulting flood of interest...

Er, yes. Anyway, I thought I'd give the interweb the benefit of my experience in the fixing of Indian-made "Serwex" brand piston fillers. The interweb doesn't want it? Too bad. It's a saga, I warn you.

So I fairly recently took delivery from India of a "new" model of pen from the Fountain Pen Revolution line of pens - the "Guru". In truth it's a slightly tweaked Serwex 162, but with a clear demonstrator model available I was an easy mark for it. FPR make Indian brands of fountain pen available outside the domestic market, and commission models of their own, and this is the latest (and cheapest) entry. They're big draw is a modern, affordable flex nib, which is really not half bad for the coinage. Add in the fact that they set up the nib for you and the darn thing flows beautifully even at full flex, and it's a steal quite honestly. So anyway, I order one clear flex Guru and about a week later it drops on the doormat. And it writes like an angel. Happy days.

About two or three weeks later, I take the thing apart to clean it thoroughly (a drawback to clear demonstrators is, of course, they can look cruddy pretty quickly if you don't stay on top of the pen hygiene), and find to my unhappiness that the piston seal has split in two. No seal, no suck. No suck, no ink. No ink, no write. Well, darn.

Now as it happens, back when I made my first order with FPR, they threw in a Serwex 162 free, gratis and for nothing. Which wrote very nicely, but had a tendency to dry out quickly, so I rather consigned it to the Box of The Damned. Or rather the Box of The I'll Do Something About That Sometime, The Gods Know When. But hey, the Guru is just a 162 in Emperor's Clothing, right? I'll swipe the piston seal from that and away I go.

Well, double darn. The piston seal on that had split as well!

Okay, maybe this is not such a good buy...

But undeterred, I look speculatively at the piston and think "Self, might not an O-ring or two go on there and maybe, just maybe, work?" Well, I'm a fairly recent convert to the all-round usefulness of O-rings, but it seemed Self might be onto something. And so it proved. A couple of O-rings a piece later and I have a functioning pair of piston fillers again. Huzzah.

But I was worried. I'd found no anecdotal evidence on the face of the interweb that the Sewex piston seals were prone to this. Was it something I was doing wrong? Was I...  a fountain pen killer?! So, just to be on the safe side, I emailed Kevin at FPR to check. His verdict? He's seen it a couple of times but I'm incredibly unlucky to have two in two.

Oh, that figures.

Anyway, he reassured me that I'm not a pen killer and kindly sent a replacement Guru, even though, as I said, I'd fixed it. Which is pretty decent service when it's got to come all the way from the sub-continent and even in the low-ticket world of Indian pens it's right down in the bargain basement section. But a week or so later, it dropped on the doormat. With another flex nib (which wasn't strictly necessary). So that was cool.

Except, er, you know that "incredibly unlucky" thing? Um... the barrel of the replacement had a crack along its length. Well, darn again. Okay, that's fine; really it's only the piston I need anyway and everything else is just icing. But, well, you can't just leave a pen to die like that, can you? I can rebuild it; I have the technology.

So it won't have bionic capabilities as a result, but also it doesn't cost six million bucks. Most importantly it won't leak. Happy days are here again. Up until this point, where we came in:

Sighing just a little (at this point I feel a little sigh was forgivable) I decided I'd cut to the chase and replace the thing straight away with the O-rings. So I went to remove it.

And then I became a fountain pen killer.

That darn thing would not shift. I resorted to dunking it in hot water for a while to make it more pliable and then attempted to twist it off.

And twisted off the entire end of the piston.

Well, darnation with a cherry on top. What a muppet. I was, and am, mortified.

Pausing only for an hour or so to berate myself for being a heavy-handed fool, I looked at what I had left. A piston shaft, but instead of a stop on the end, a gap about two O-rings wide, and then another stop, I had a shortened piston shaft with a stop on the end and nothing to keep any O-rings in place.

Am I going to let this thing die now? Like heck I am; I'm invested in its continued good health and working ability. We'd been through solvent welding together, dammit. All I needed was a new stop to put the O-rings between. So, not for the first time, I dug out the bag of parts salvaged from my old VHS tapes, and selected one of the plastic guide spindles. Turns out a Japanese saw does a good job of splitting these things in two, and with a liberal application of a two part epoxy, I have... a bodge.

Top is the pen barrel and piston knob; next is the full length piston with O-rings; then the split original seal; finally the truncated piston with a new stop and a spacer to stop it going too far into the piston knob and failing to advance again.

Close-up you can see a) It's not pretty (but then neither is the unmolested one), and b) The built-up bead of epoxy just to give the O-rings a little more to bear on.

The reassembled pens, and honestly, it's a lot better than I deserve. Of course you wouldn't do such a bodge on a Pelikan or the like, but with the normal appearance of these pens prizing function over aesthetics anyway, I think I got away with it okay in this case.

As I prize function over appearance too, the important bit was whether it would work. A careful first run of soapy water to test for leaks was successful, and it's now been inked-up for nearly a week and no trouble yet.
Writes really nicely, actually. On this experience I couldn't honestly say they're a great pen, but they have a naive charm that I find irresistible. Actually I've yet to try an Indian pen that hasn't made me smile. And unfortunately, in many cases, swear a little. But that's half the fun.



  1. Thanks Alf. I have a few FPN pens myself and may have to do the same myself one day.

  2. It might be worth investing in some Sugru ( for future experiments.

    1. Ah, I've been looking at that for other purposes funnily enough, but must admit its cost has thus far stayed my hand. The curse of being an Alf of the McAlfs... ;)


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