Jump to content

How Do You Achieve A Good Seal On A Parker 51 Sac?

Venemo

By Venemo
in Repair Q&A

 Share

Recommended Posts

Venemo Extremely Rare

Venemo

Posted
Posted

I have a few Parker 51 pens that I've taken apart, cleaned out, and now it's time to replace their sacs, so I thoroughly removed any gunk and residue from the sac nipple, then shellac'd the new sac and left it to dry for a day or so.

 

The result: after the shellac dries, it seems that it doesn't provide a good air seal. There seem to be "bubbles" under the sac between the "ridges" of the sac nipple, and as I apply some pressure on the sac, it starts to separate from the sac nipple very easily. For this reason, I'm too afraid to put this in a pen, because even though it sold of holds, I'm afraid it would come loose and start to leak soon. It also seems that the shellac is weak, if I apply very little force the sac comes off easily.

 

I've now repeated the process 3 times, tried 2 different kinds of shellac, each time cleaning out the gunk and residue from the previous attempt carefully. But I always get the same result. What am I doing wrong? Is there a trick that I'm missing here?

 

This feels very silly because I was able to do this successfully in the past but for some reason I can't get it right this time.

Link to comment
Share on other sites
  • Replies 8
  • Created
  • Last Reply

Top Posters In This Topic

  • gweimer1

    3

  • Venemo

    2

  • gyasko

    1

  • eachan

    1

Popular Days

Top Posters In This Topic

Popular Days

eachan Rare

eachan

Posted
Posted (edited)

The Pliglass sacs that are in Aerometric Parker 51s rarely fail and on the odd occasions when they do it's usually as a result of damage. They do become discoloured but that's not a reason for replacement. None of the sacs produced today will last as long as the original. It is well known that shellac is not a suitable adhesive in this situation. Unfortunately I don't know what is used but a search of this site should provide the answer. It's one of the araldites, I think.

Edited by eachan

Regards,

Eachan

Link to comment
Share on other sites
gweimer1 Antique

gweimer1

Posted
Posted

I was always taught that shellac was the adhesive to use on the pli-glass sacs, and I've never had any issues with it to date. The Marshall-Oldfield book also mentions that nail varnish is a good adhesive for these.

Link to comment
Share on other sites
Ron Z Museum Piece

Ron Z

Posted
Posted

The 51 uses a #15 sac, which is what David Nishimura's are... they're really identical to the originals. They also don't need to be trimmed at all. You can also use a #16 PVC sac. I find that they are a pretty snug fit on the 51 sac nipple, which is long enough that they don't pull off. I haven't had a 51 sac come loose. But having said that, there are a couple of things that I do.

 

1 - I always clean the inside of a PVC sac with a Q-tip soaked with denatured alcohol, then dry it with the other end, especially at the opening. This cleans out any of the mold release compound that may have been left behind, so the ink flows properly and the sac sticks better.

 

2- I scuff up the sac nipple with just a couple of turns of 220 grit sand paper. This also helps the sac to stick better.

 

3- I use shellac. Since the sac nipple is plastic, I don't feel comfortable using a solvent based cement. Put a good coating on (don't be stingy), slide the sac on and twist it a bit so that it is distributed inside. You should end up with a bead or fillet at the forward end of the sac. Leave it there and let it harden, then put the sac guard on after it dries. Note that the pressure on the sac from the pressure bar is back a ways, not near the nipple, so it should not disturb the seal at all.

 

"nail varnish" = nail polish, which contains acetone. This is one of the few areas where I disagree with my friends and colleagues in the UK.

spacer.png
Visit Main Street Pens
A full service pen shop providing professional, thoughtful vintage pen repair...

Please use email, not a PM for repair and pen purchase inquiries.

Link to comment
Share on other sites
pajaro Museum Piece

pajaro

Posted
Posted

Thank you Ron Z.

"Don't hurry, don't worry. It's better to be late at the Golden Gate than to arrive in Hell on time."
--Sign in a bar and grill, Ormond Beach, Florida, 1960.

 

 

Link to comment
Share on other sites
Venemo Extremely Rare

Venemo

Posted
  • Author
Posted

You have that many with failed sacs?

 

Yes, these are used from ebay.

 

Why kind of sacs are you using? How old is the shellac?

 

The sacs are brand new from the Pendragons.

I tried two types of shellac, one I bought from the Pendragons about 2 years ago, the other I got in a local store brand new.

 

The Pliglass sacs that are in Aerometric Parker 51s rarely fail and on the odd occasions when they do it's usually as a result of damage. They do become discoloured but that's not a reason for replacement. None of the sacs produced today will last as long as the original. It is well known that shellac is not a suitable adhesive in this situation. Unfortunately I don't know what is used but a search of this site should provide the answer. It's one of the araldites, I think.

 

The sacs are brand new from the Pendragons. The originals were severly discolored, twisted, some of them already came off.

 

One thing to check - how is the nipple underneath the sac? Is it hard, or has it gotten soft?

 

It is hard.

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Most Contributions

    1. amberleadavis
      amberleadavis
      43844
    2. PAKMAN
      PAKMAN
      33558
    3. Ghost Plane
      Ghost Plane
      28220
    4. inkstainedruth
      inkstainedruth
      26730
    5. jar
      jar
      26101

  • Upcoming Events

  • Blog Comments

    • Shanghai Knife Dude
      Links to web pages or articles about Chinese typesetting, signwriting, etc.

      By Shanghai Knife Dude · Posted

      I have the Sailor Naginata and some fancy blade nibs coming after 2022 by a number of new workshop from China.  With all my respect, IMHO, they are all (bleep) in doing chinese characters.  Go use a bush, or at least a bush pen. 
    • A Smug Dill
      Skeleton of a primer for a budding hobbyist

      By A Smug Dill · Posted

      It is the reason why I'm so keen on the idea of a personal library — of pens, nibs, inks, paper products, etc. — and spent so much money, as well as time and effort, to “build” it for myself (because I can't simply remember everything, especially as I'm getting older fast) and my wife, so that we can “know”; and, instead of just disposing of what displeased us, or even just not good enough to be “given the time of day” against competition from >500 other pens and >500 other inks for our at
    • adamselene
      Skeleton of a primer for a budding hobbyist

      By adamselene · Posted

      Agreed.  And I think it’s good to be aware of this early on and think about at the point of buying rather than rationalizing a purchase..
    • A Smug Dill
      Skeleton of a primer for a budding hobbyist

      By A Smug Dill · Posted

      Alas, one cannot know “good” without some idea of “bad” against which to contrast; and, as one of my former bosses (back when I was in my twenties) used to say, “on the scale of good to bad…”, it's a spectrum, not a dichotomy. Whereas subjectively acceptable (or tolerable) and unacceptable may well be a dichotomy to someone, and finding whether the threshold or cusp between them lies takes experiencing many degrees of less-than-ideal, especially if the decision is somehow influenced by factors o
    • adamselene
      Skeleton of a primer for a budding hobbyist

      By adamselene · Posted

      I got my first real fountain pen on my 60th birthday and many hundreds of pens later I’ve often thought of what I should’ve known in the beginning. I have many pens, the majority of which have some objectionable feature. If they are too delicate, or can’t be posted, or they are too precious to face losing , still they are users, but only in very limited environments..  I have a big disliking for pens that have the cap jump into the air and fly off. I object to Pens that dry out, or leave blobs o

  • Chatbox

    You don't have permission to chat.
    Load More

  • Files






×
×
  • Create New...