The Blue Fingers Blog

There’s a reason why I say  that professional pen repair involves a lot more than knowing how to replace a sac.

Repairing pens as I do, I see a lot of repairs that are done by what I’m not sure,  but repair mechanic doesn’t apply.  Sometimes I think that a monkey could have done a better job, but those are the extreme cases.  Often the repairs are a bit more “creative” than they should be, and at other times whomever worked on the pen just didn’t have their thinking cap on.

Two cases today.  Pen #1 was a Parker 51 aerometric with the early “press 6 times” sac guard, and a chrome, polished cap with a black jewel.  I don’t know if the owner knows that the cap is from a 51 Special or not.  I decided not to bring it up since they seemed to be content with it. If someone sends a 51 aerometric to me to restore, I check the plyglass sac, but don’t routinely replace them.  I believe that nothing that we have today is better than an intact, properly functioning plyglass sac.  Maybe a silicone sac will last longer, but I doubt it.

So problem #1 – replacing a plyglass sac with a latex sac, which of course had failed.   Plyglass sacs should be replaced only under two conditions; a punctured sac (it happens) or a damaged/soft sac nipple.  If the later, the connector has to be replaced or repaired (new sac nipple installed) and a new sac installed.

Problem #2 was that the sterling silver breather tube had been replaced with (this is creative) 1/2 WD-40 spray tubing, and 1/2 original celluloid tubing, glued and jammed together, which didn’t hold together.  On top of that they had bored out the feed to take the larger tubing, which meant that the hole in the end of the feed was now oversize.  There is a way to sleeve a feed to take the standard size stainless replacements that I make, but we could have ended up replacing that too.  The right breather tube does make a difference.

The second pen was a Conway Stewart.  Pretty pen, but it didn’t fill right, and of course didn’t write well.  When I opened the pen I was surprised to find that the sac was good, and relatively new.  But there was something rather hard inside inside the sac.  I pulled it off, and found the problem.    The feed was a replacement feed, I assume installed at the last repair.  It stuck out about 1/2″ beyond the end of the sac nipple, instead of being flush or below the edge, which was why the pen wouldn’t fill.  Sticking out that far it slipped under the end of the J bar and interfered with it’s operation.  The lever might flex the J bar a bit.  But the sac wasn’t compress enough if at all, and the pen couldn’t fill.  I knocked out the nib and feed to make sure that they were clean and clear. I then reassembled to mark the feed, knocked it out to cut it to the right length, and assembled again.  The pen fills just fine, and writes nicely.

“So,” you’re asking, “where are we going with this?”  Two things, maybe three.

First is that if you are going to repair pens you should have some idea how they are designed, and an understanding of why they were made the way that they were.  Sometimes we have to be creative with our repairs.  But often procedures are followed, and materials used simply because they are expedient.  “Fix it” and get it out the door instead of making sure that the repair is as close to the original configuration as possible and that it is done right.

Second,  we need to think about what we’re doing.  If the person who put that feed in the Conway  Stewart had simply observed (thank you Sherlock) they would have known that the pen wouldn’t work, that it couldn’t possibly fill properly with the feed that long.  But they didn’t change the length of the feed.  They weren’t thinking.

Third, a pen should always be tested, i.e filled and written with, before it goes out the door.  ALWAYS.   I can’t believe that whomever worked on the pen  had tested it before sending it out.  If they had, they would have known that the pen wasn’t working.

All a little more than just replacing a sac, don’t you think?

It happened again today.  I was working on a Mustard 51 that had a crack in the barrel, at the filler end (where else?), getting ready to do the first stage of blending the repair.  I was installing the filler so that I could check the blind cap/barrel alignment and looked inside with a flashlight to make sure that the seat was smooth because the repair went across the threads and seat inside the barrel.

I won’t go into all of the details of the repair in this post – it’s enough to say that the pen had been repaired in the not too distant past and the sac was still still pliable, though twisted into a knot.

But whomever had done that repair had not done it right.  There in the barrel, all of the way around was about an inch of dead diaphragm stuck to the barrel wall.  The cleaning that I had done to remove it from the crack had not softened it one bit.  It was stuck.

I see this quite often when a pen has been “repaired” by an amateur.  Whether a sac pen or a vacumatic filled pen, it’s not uncommon to see the remains of the previous sac still stuck to the barrel wall, pressure bar or diaphragm.  So why is that a such a bad thing?

For a sac pen there are a couple of problems.   If stuck to the barrel wall, and/or the pressure bar, the old sac will reduce the inside diameter of the pen.  The typical amateur will then grab a smaller sac, using in some cases a #16 where a 18 or 19 would be appropriate.  This reduces the ink capacity significantly, and the sac has a tendency to slip off of the section because the sac has to be stretched too much.  If it’s stuck to the section, the extra layer may make the section too big to fit into the barrel without force, and it keeps you from getting a good seal on the section.

In a Vacumatic filled pen remains of the old sac on the barrel wall can cause the diaphragm to bind as you press the plunger down to fill the pen.  If the old diaphragm isn’t cleaned off of the seat in the barrel, you’ll have an extra layer (as if you had two diaphragms stacked one on top of the other).  This will keep the filler from screwing into the barrel as far as it should.  The pen can leak, and the blind cap may not screw down as far as it should.  The typical amateur then tries to compensate by tightening the filler in even harder, which can cause barrel bulge or crack the barrel.  I’ve seen it all, and it’s not pretty.

I know that it takes a little more work to get it ALL out, but it’s worth the effort.