Vac Pellet Cup Extractor

[Dmills]

I’ve been lurking for a while now but finally felt I had something worthwhile to post. I’ve been collecting pens (mostly Parkers) for a few years and recently decided to jump in a restore a few of them. I’ve restored a few of my Duofolds and Vac’s over the last year with the help of the generous contributions on this site as well as the many great pen resources on the web.

 

I recently acquired a Parker Senior Duovac and had it disassemble and cleaned when I noticed the pump spring was heavily corroded and had separated. Dang! What to do now? A bit more searching turned up a few sites with replacement springs and pellet cups for sale and the most common recommendation seemed to be that the existing pellet cup usually had to be cut off of the filler plunger in order to install a new spring as it is generally very difficult to remove the cup without damaging either the cup or the plunger shaft. Seemed a waste to destroy a perfectly good cup so I decided to see if I could come up with a pellet cup extractor.

 

The jig materials were some simple scrap from my wood shop – a piece of 2x4, a threaded eye bolt, the end of a drill bit and some copper sheet. I selected a drill bit with a diameter a few thousands smaller than the filler plunger diameter and used the bit to countersink a hole in the end of the eye bolt. I then cut a section off the shank of the same bit and inserted it into the drill hole to serve as the ram. I warmed the pellet cup up once mounted in the jig to 150 degrees for a few minutes monitored by a digital thermometer and then slowly turned the eye bolt and pushed the plunger shaft out the back of the pellet cup. No big issues except that one of the slot legs on the end of the plunger shaft was slightly bent over but I think that can be straightened with a little more heat with I reassemble.

 

So, my rough little jig seems to have worked at least on this first attempt. Anyone else used something similar with good results?

 

Is the pellet cup reattachment usually done with a dab of shellac?

 

Thanks.

 

[tamiya]

Interesting exercise, thank you for your thorough write up.

 

Is this still a Work in Progress? eager to hear how the finished job looks/works.

[FarmBoy]

Celluloid glue or acetone.

[Dmills]

Thank you for the comments. Just placed a parts order today so this one should hopefully join the current daily writer rotation next week.

 

 

[FarmBoy]

The Geometric pens shown don't have Vacumatic fillers do they?

[Dmills]

No, they are both button fillers. There was a lot of material rattling around in their barrels before I disassembled them so I assumed the pressure bars were going to be toast but it ended up just being loose petrified sack.

[Dmills]

One more question. Replacement spring should be coming in tomorrow' s mail. FarmBoy, you had suggested using Acetone to reglue the pellet cup to the plunger shaft. Is it as simple as just brushing on some acetone on the shaft end and sliding the pellet cup home? Is a couple of hours enough for the cure time or does it need a full 24 hours?

 

Thank you.

[FarmBoy]

If the original pellet cup was celluloid just wet the shaft a few times an the inside of the cup and push it together. This only works if both parts are celluloid.

[Dmills]

Thanks. To test just apply a small dot of acetone to the outside of the cup with a toothpick and see if it softens the material after a few minutes? If not, option B would be a 2 part epoxy?

[Dmills]

Finished repairing the fill unit last night and have reassembled the pen. Unfortunately the old pellet cup crumbled on me while I was reheating it to reduce the pellet cup opening diameter a bit. Fortunately, I had ordered a new hard rubber cup along with the replacement spring which I was able to install with no issues after slightly reducing the diameter of the plunger shaft tip.

 

Below is a pic of a simple spring retraction jig used to expose the shaft end for the cup glue up. I ended up using medium viscosity cyanoacrylate as the adhesive after confirming with Ron Zorn and Dale Beebe with pentooling.com (thank you both).

 

Very stiff nib like most Parkers I have.

 

Hope this may be of some help to anyone else who might be trying a first attempt at a Vac filler unit spring replacement.