Wahl Oxford Twist Fill Repair

[Wahlnut]

Revised

 

Many moons ago I promised to post an article on the repair of the innards of the Wahl Oxford Twist Filler Pen. This pen seems to have gained the reputation of being one of the more difficult to make work again. While some of the reputation is true it is not completely impossible either. Any one with a copy of Frank DuBiel's Fountain Pen Repair can easily find the pages where the process is described and the drawings help a lot too. Here is a copy of the diagram that is most germane:

http://i9.photobucket.com/albums/a75/wahlnut/Twistfilldiagram.jpg

 

Diagrams are nice but sometimes it is easier to see the real components as they appear to the repair person:

Now attach the closed end of the sac to the square cup in the inside of the twist fill mechanism with Here is the pen mostly dis-assembled with the barrel innards except for the permanent central grommet and the tempered steel securing washers that hold the grommet in place.

http://i9.photobucket.com/albums/a75/wahlnut/PB110350OxfordGuts1-1.jpg

 

The twist mechanism also comes apart in 3 pieces - the red plastic twit fill knob, the threaded twist fill housing and the twist fill cup and threaded shaft that the red knob screws onto. It is necessary to take the twist mechanism apart to do the repair. It will be necessary to remove the red knob prior to re-assembly in order to screw the housing back into the end of the barrel without twisting the sac as that is done. (the housing takes about 3 complete revolutions to seat and the sac if binding, will get twisted which must be avoided in order for the twist filler to work.)

 

The size of sac that you see loose, above is not cut to size yet. Also the sac above was chosen at random based on what I had the most of at the time. That it is necked, is of no significance here. As a matter of fact the neck was discarded in this case. The sac diameter to choose is whatever you have that is just smaller than the pen barrel (small enough that the sac does not rub against the barrel inner wall). The approximate length of the trimmed sac will not be more than approx. 1 1/4". So choose a sac where the loss of excess sac when trimmed will be minimized. Getting the right length is tricky as it must be measured with a depth gauge from the rear of the open barrel to the central grommet. but the rule of thumb is to cut the sac such that when the sac is secured to the hollow, threaded screw head, the sac end is 1/16" recessed inside the barrel end. Attaching the sac to the screw head is a little tricky because the surface area of the screw head sides is not very great. Use shellac. I have found that if the sac is the right diameter it will need to be stretched a little to go over the screw head and cup slightly beyond the screw head as shown in DuBiels diagram above. This tension helps to secure the sac to the screw head better.

 

Here is a picture of the exploded parts with the sac in place on the threaded screw head and the closed end of the sac attached to the little square swivel cup in the inside if the twist fill mechanism. I will insert another picture of the exploded twist fill mechanism later on.

http://i9.photobucket.com/albums/a75/wahlnut/PB130351OxfordGuts2.jpg

 

Next one inserts the sac and hollow screw unit into the back of the pen barrel. Then the threaded nut goes into the front of the barrel. The threads of the screw will protrude beyond the central grommet so that the nut can be screwed onto the screw pulling the screw head and sac snug against the central grommet. The nut has 2 grooves cut into it on one side. This allows the use of the split screw-driver that Father Terry sold to many folk. But you can make your own if need be. Only when this is done should you attach the closed end of the sac to the twist fill cup and shaft part of the twist fill mechanism. They used shellac at the factory, but today we use super glue gel because it sets quickly and seems to last longer.

You can insert a thin dowel all the way from the section end of the barrel up through the hollow threaded screw into the sac to apply pressure to the sac end while gluing the sac end to the shaft cup. When this is done, the twist fill shaft will stick out of the back end of the barrel.

 

Slip the twist fill housing over the shaft, and screw it into the barrel end. When seated properly the housing will sit slightly below the back barrel lip. It will be necessary to push the twist shaft in a little when screwing in the housing as it tends to bind and then the sac gets all twisted in the process. When seated test that the sac is not twisted with the dowel. When that is done re-attach the red twist fill knob. If done correctly, you will see that the twist fill knob can be rotated about 350 degrees and will snap back to starting position for another twist. It snaps back because of a tiny circular spring inside the back end of the twist fill housing and the rubber sac's "memory" working together. Each twist expels one sac's worth of air and when released draws in one sac's worth of ink. When the sac untwists, the ink flows up through and overflows the end of the the breather tube flowing downward around the breather tube and through the hollow screw into the barrel cavity reservoir. It may take more than 5 twists to fill the resevoir as each twist can only add it's contribution to the reservoir limited to whatever the internal volume of your sac actually is.

 

In the interest of time, I am posting this article now but will return to edit it and add more information a little later.

 

Hope this proves interesting to you all.

 

Syd the Wahlnut

Edited January 20, 2008 by Wahlnut

[Alriel]

Syd,

 

All I can say is wow! I had Da Book and had the pen in front of me, but looking at it in the exploded detail still looks imposing. I can only imagine how you were able to remove the twist fill assembly. (I imagine with a vac-tool like device?) I look forward to updated edits!

 

Full disclosure - I am the owner of the pen in the example and am very ahppy with the results. The pen is working great and expels fluid quite forcefully.

 

Al

[david i]

Revised

 

Many moons ago I promised to post an article on the repair of the innards of the Wahl Oxford Twist Filler Pen. This pen seems to have gained the reputation of being one of the more difficult to make work again. While some of the reputation is true it is not completely impossible either. Any one with a copy of Frank DuBiel's Fountain Pen Repair can easily find the pages where the process is described and the drawings help a lot too. Here is a copy of the diagram that is most germane:

http://i9.photobucket.com/albums/a75/wahlnut/Twistfilldiagram.jpg

 

Diagrams are nice but sometimes it is easier to see the real components as they appear to the repair person:

Now attach the closed end of the sac to the square cup in the inside of the twist fill mechanism with Here is the pen mostly dis-assembled with the barrel innards except for the permanent central grommet and the tempered steel securing washers that hold the grommet in place.

http://i9.photobucket.com/albums/a75/wahlnut/PB110350OxfordGuts1-1.jpg

 

The twist mechanism also comes apart in 3 pieces - the red plastic twit fill knob, the threaded twist fill housing and the twist fill cup and threaded shaft that the red knob screws onto. It is necessary to take the twist mechanism apart to do the repair. It will be necessary to remove the red knob prior to re-assembly in order to screw the housing back into the end of the barrel without twisting the sac as that is done. (the housing takes about 3 complete revolutions to seat and the sac if binding, will get twisted which must be avoided in order for the twist filler to work.)

 

The size of sac that you see loose, above is not cut to size yet. Also the sac above was chosen at random based on what I had the most of at the time. That it is necked, is of no significance here. As a matter of fact the neck was discarded in this case. The sac diameter to choose is whatever you have that is just smaller than the pen barrel (small enough that the sac does not rub against the barrel inner wall). The approximate length of the trimmed sac will not be more than approx. 1 1/4". So choose a sac where the loss of excess sac when trimmed will be minimized. Getting the right length is tricky as it must be measured with a depth gauge from the rear of the open barrel to the central grommet. but the rule of thumb is to cut the sac such that when the sac is secured to the hollow, threaded screw head, the sac end is 1/16" recessed inside the barrel end. Attaching the sac to the screw head is a little tricky because the surface area of the screw head sides is not very great. Use shellac. I have found that if the sac is the right diameter it will need to be stretched a little to go over the screw head and cup slightly beyond the screw head as shown in DuBiels diagram above. This tension helps to secure the sac to the screw head better.

 

Here is a picture of the exploded parts with the sac in place on the threaded screw head and the closed end of the sac attached to the little square swivel cup in the inside if the twist fill mechanism. I will insert another picture of the exploded twist fill mechanism later on.

http://i9.photobucket.com/albums/a75/wahlnut/PB130351OxfordGuts2.jpg

 

Next one inserts the sac and hollow screw unit into the back of the pen barrel. Then the threaded nut goes into the front of the barrel. The threads of the screw will protrude beyond the central grommet so that the nut can be screwed onto the screw pulling the screw head and sac snug against the central grommet. The nut has 2 grooves cut into it on one side. This allows the use of the split screw-driver that Father Terry sold to many folk. But you can make your own if need be. Only when this is done should you attach the closed end of the sac to the twist fill cup and shaft part of the twist fill mechanism. They used shellac at the factory, but today we use super glue gel because it sets quickly and seems to last longer.

You can insert a thin dowel all the way from the section end of the barrel up through the hollow threaded screw into the sac to apply pressure to the sac end while gluing the sac end to the shaft cup. When this is done, the twist fill shaft will stick out of the back end of the barrel.

 

Slip the twist fill housing over the shaft, and screw it into the barrel end. When seated properly the housing will sit slightly below the back barrel lip. It will be necessary to push the twist shaft in a little when screwing in the housing as it tends to bind and then the sac gets all twisted in the process. When seated test that the sac is not twisted with the dowel. When that is done re-attach the red twist fill knob. If done correctly, you will see that the twist fill knob can be rotated about 350 degrees and will snap back to starting position for another twist. It snaps back because of a tiny circular spring inside the back end of the twist fill housing and the rubber sac's "memory" working together. Each twist expels one sac's worth of air and when released draws in one sac's worth of ink. When the sac untwists, the ink flows up through and overflows the end of the the breather tube flowing downward around the breather tube and through the hollow screw into the barrel cavity reservoir. It may take more than 5 twists to fill the resevoir as each twist can only add it's contribution to the reservoir limited to whatever the internal volume of your sac actually is.

 

In the interest of time, I am posting this article now but will return to edit it and add more information a little later.

 

Hope this proves interesting to you all.

 

Syd the Wahlnut

 

 

Nice! One of my favorite restorers partways out west has had one of mine for like three years. Actually, maybe 5 years. Each time i ask about it at pen shows i get the evil eye. Think i'll forward this post

 

regards

 

david

 

[Johnny Appleseed]

Syd,

 

Great description and great tips for how to repair these.

 

However, one important piece of this is missing. How does one get the threaded screw that the sac attaches to out of the barrel?

 

I know "Da Book" says you remove the slotted nut and the threaded screw and sac assembly fall out of the barrel.

:roflmho:

 

With my two attempts I was not able to get the threaded screw out without a lot of heat and the process resulted in the washer assembly that holds it in place coming out as well, and the washer assembly got distorted in the process. I have been trying to make a replacement for the washer assembly. Put it on the back burner for a while though.

 

Do you have any tips for getting the threaded screw out if it is being persnickity?

 

BTW - Victor Chen also addressed these in one of his articles in either the Pennant or Pen World. I will have to check my references to find the article.

 

John

[Wahlnut]

Hi John,

I know what you mean. No repair manual can possibly say it all. The manual gives some solid basics and tried and true methods that have worked for the author. But it is practically impossible to cover everything. Especially if you only devote 1 page per pen! What is NOT written in Da Book, are 1) that the repair person possesses some basic mechanical skills with a knowledge of the propertuies of the materials involved with the materials pens are made of. And 2) some things that if written might have some folks aghast because, in moderation, it is sometimes necessary to use small amount of otherwise "forbidden" chemicals in short controlled timeframes to get things to separate. However short of those last resorts methods (which I can go into the next time we have a campout and are telling scary stories) , there are some "mechanical" methods that might be of use.

 

In most cases the rubber sac has become agressively attached to the central grommet and the screw because of the natural deterioration of the sac and the pressure that the sac was under right at the place where the sac was compresed between the screw and the grommet. Also, there is the strong liklihood that this is not the first time the sac has needed replacement over the years, and no one really knows what methods some previous repair hack has used and that you now have to diagnose and overcome.

 

Anyway, if you can remove the nut, you will find that the threaded part of the screw protrudes enough beyond the grommet, that something long and relatively soft like a wooden dowel can be inesrted up the front of the barrel and with some light heat (like no more than say 130-140 degrees F) moderate rapping with a leather mallet may knock the screw out through the grommet. (The screw is not held inside the gromet by anything other than the nut- the grommet is not threaded) By the time you are trying to do this, you have already removed the twist-fill housing from the back end of the barrel, so you can get at the top side of the screw (the sac is already gone by this time. If the culprit is that the sac has deteriorated (melted) so as to form a bond between the sides of the screw head and the inner barrel sides, you can gently remove the old rubber at the sides of the screw head with a dental tool. Often that is enough to clear away enough old sac bond to let the dowel do its job from the front end. A little sudsy ammonia and water helps at or ahead of this point too. There are other methods that might work too, but this may be enough to think about for now.

 

And remember that even if you do damage the central grommet, you can replace that too so long as you remove the retaining spring steel washers and ream out the rubber grommet, replacing it with another. Been there, done that too.

 

And, David, I would be surprised if another Pro repair person "Out West" would not know this information or have even better methods than me. So if your pen has not come home for that long, I would think there is another reason.

 

Syd

 

 

[Johnny Appleseed]

Thanks Syd (and Touche, I guess?)

 

I wasn't trying to knock the instructions, or "DaBook", just commenting that the one place where he made it sound easy wasn't necessarily so. It is sort of like saying that for a Sheaffer Vac filler you just have to unscrew the section and drill out and replace the packing unit. Sounds simple enough, until you find you piston shaft is rusty, and that there are 8 different possible sizes to look for if you want to find a replacement, and. . .

 

I basically did as you suggest - tried to use a dowel to knock out the threaded screws, after I scraped off the old sack from the other side. It would not budge until I heated it up pretty good - probably applied a little too much heat, actually - and the whole central grommet assembly came out. The retaining springs were not steel, however, but some sort of plastic and warped just enough that it would not hold when re-inserted. Worse though is the central grommet did not want to come off the threaded screw until it cracked.

 

I am looking at using something to replace the central grommet, but I am not a lathe guy, so it may be a bit.

 

These still qualify as more difficult than a Sheaffer Vac-filler in my eyes, but maybe that is just because I have not done as many.

 

John

Edited January 25, 2008 by Johnny Appleseed

[Wahlnut]

Well, John,

Just because a thing can be described does not necessarily make it easier. I have been trying to fix some SAMBA file that enables Judi's Mac to network print through my XP desktop as a server. It worked once then stopped. I printed out the instructions on how to diagnose and repair this last August! I read and reread it...clear as mud! I still do not know what to do to get it right. So, have I called in my Rotay Club buddy professional computer guy and accepted the fact it's gonna cost me some bageetas??? NNNNOOOOO. I can do it! ...maybe not.

 

Some pens have led a life that makes them easier to work on than others. Not all Twist Fillers will respond the same. Some have been through environmental hell as far as pen storage conditions go. Some have been restored at one or more points along the pen's life. If done correctly in the past the relatively newer materials, though worn out again, will be easier to work with than 70 year old brittle materials. Some folks did not use shellac, they may have used another cement that is less workable. You deserve an A for effort and nerve. I had more than a few mishaps along the old learning curve, too, you know. It also helps if you have a parts bin with "back-up" parts in case of a blow-out, too. Hmmm. just where did all the spare parts come from :-)

 

I know you like to work on a tough project as much as anyone...until you git er done. So good luck with the ongoing and deepening project. Just remember there is no shame if at some point you just want to turn it over to another set of hands when necessary. I can repair my MG TC all by myself, thanks. But the Jag? Hmmm don't even want to get started!

 

Syd the Pen Philosopher Wahlnut

 

toWorking with dissicultmake it

[LedZepGirl]

Thank goodness for this! I received one of these pens for Christmas and I've been wondering how to take it apart.

[Wahlnut]

Another oldie but goodie post that keeps on giving. Proving there is a lot of information here on the forum for those who search for it.

Syd

[LedZepGirl]

Just wondering, what's the best way to go about getting the twist fill unit out of the pen?

 

Also, are the threads reverse or normal. I'm having trouble getting the section out.

Edited January 8, 2014 by LedZepGirl

[j-e-g]

Another oldie but goodie post that keeps on giving. Proving there is a lot of information here on the forum for those who search for it.

Syd

 

I picked this up at a re-sale shop. I am glad to learn a little more about it.

 

 

Can anyone give me an estimate of how much and/or who restore these ?

[sztainbok]

Hi Syd,

I started following you instructions and got to the point where I was not able to figure out how to disassemble the filler unit.

There appears to be a knock out pin on the red twist button. Should I knock it out?

Thanks,

Victor.

[Greenie]

It can be done different ways. I have restored three of these. I knock out the pin so I can unscrew the red knob from the pin that attaches to the sac on the inside.

 

***Be careful not to lose the ring that sits under the red knob.

 

Once you remove the twist mechanism from the end, and remove the section from the front end, you have to deal with the filling unit. It is easy to make a spanner with a dremel and a flat head screwdriver and then remove the section end retaining ring.

 

As long as you can get the sac retaining threaded screw out, follow as above. However, there are a few ways to deal with the sac attachment to the twist unit.

 

However, I have found that the threaded screw that holds the sac is stuck to the "permanent" gasket and concave washers in two out of three of my restorations.

 

When the threaded screw that holds the sac is stuck, I have just knocked out the entire structure through the back end of the pen. Once you rebuild the sac, threaded portion, concave washer, gasket, concave washer, and retaining ring, you can slide it back into the pen, CAREFULLY position it to the correct point, and apply a little shellac from the front. I replace the original gasket with a new o ring. On one pen, it was fine, and on the other, I had to sand it down a bit.

Edited November 6, 2017 by Greenie

[Greenie]

I apologize for anything that does not make sense. I hope the images will help.

 

If you can follow the advice above - DO IT! IT IS MUCH EASIER!

 

Remove the section, and unscrew the twist fill unit. They are standard thread. Then try to fix the pen using Syd's much better approach, leaving the middle insides of the pen in place.

 

If things are stuck, and heating, soaking, ultrasonic bath, and potions that loosen stuck things all fail, put the section end retaining ring back on the filling unit using your spanner.

 

Then take a chopstick or something via the section end, and put the twist end against a suitable surface, and drive out the pen insides. They are just friction fit. A celluloid washer on either side of a rubber gasket that has become hard and brittle.

 

Replace the old center gasket with O ring. I used a #78, 7/16 OD, 1/4 ID x 3/32. It fit one pen perfectly, and it was a hair big for the second one. You might have to put it on a rod in your drill and sand down the outside to reduce the diameter. Put in the threaded screw that holds the sac, and the retaining ring on the other end, Basically, put it together without the sac.

 

You will be dry fitting the unit, minus the sac, to be sure the O ring is not too big. At some point, when you like the size of the O ring, position the assembly where you believe the final location will be. Frankly, the barrel begins to taper slightly toward the section end at the location you need.

 

Then measure that depth and mark it on a chopstick. Now you can cut a sac to length using the mark on the stick, and reassemble everything. Then push it all into the pen. I show the sac inverted so a chopstick can be put inside and push on the hard pieces to get them in place Another stick on the section end can facilitate positioning.

 

Once in place, dribble a few drops of shellac on the section end of all the stuff you just placed. Use a blunt needle, syringe, long tiny plastic pipette, etc.

 

After it dries, you can just blow on the section end and puff the sac back out, or gently use a narrow rod.

 

At that point, you have to deal with the twist mechanism (that can be another post - I don't have those pictures unfortunately)

 

 

 

 

[sztainbok]

Thanks very much. Your description helped me and I was able to take everything apart. To my surprise, I found that someone had already been inside that pen, and it was missing the o-ring and one of the celluloid washers. I can source an o-ring locally but I don´t know where to go for the celluloid washer. Can someone help me? Thank you,

Victor.

[Greenie]

Just ignore it! If you are doing my style of repair, the mechanism will be held in by a drop or two of shellac, so the celluloid rings become unimportant.

[FarmBoy]

I believe the proper term for this type pen is 'demanding filler'.

[Greenie]

Final steps of the restoration:

 

Take apart the twist filler. If there is a pin, you will need to knock it out.

The red knob unscrews in the standard direction. There is a metal ring with a protrusion underneath. Be careful to save it.

So the parts are:

1. collar

2. red knob

3. washer that limits rotation

4. threaded shaft (that attached to sac on inside, and knob on outside)

 

 

Use a drop of superglue and simply glue the metal cup internal end of the threaded shaft to the end of the sac. I like the gel type of super glue for this, so it won't accidentally run down the side of the sac, or be sure to do the whole thing with the sac pointed down.

 

Once it dries, put the collar back on. I would bet anyone who has made it this far can figure out how to position the rotation limiting ring in a pleasing and functional way. Put it in so you get nearly a full turn of the knob before it hits the "stop." Then just screw the red knob back on. The pin is unnecessary, but I guess you could try to line everything up and replace it if you wish.

 

 

A note about the sac attachment to the metal cup on threaded shaft. There is a square of plastic that "technically" goes inside the sac so you can snap the end of the sac into the shaft (like the tiny ball on a vacumatic diaphragm). You could choose to free up and remove that piece, which likely requires some bending of the metal cup, and then put it in the sac early in the repair and use it to lock the sac on the shaft prior to re-inserting the entire sac holding mechanism. To be honest, glue seemed easier, and it seems to be holding just fine. I did not like the idea of bending the metal part that could not be replaced or easily remade if damaged too much. Glue comes off he metal with nail polish remover or acetone, so it seems to be a reversible repair until or unless someone describes an easier way.

Edited November 12, 2017 by Greenie

[fountainpen51]

rescuing this post, I am disarming the inner nut, I see that it turns and turns, but it does not come out and it does not really seem that it has intention to leave at first sight, since although it rotates the inner nut with the screwdriver, it does not seem that it leaves. any ideas?

[fountainpen51]

Some photos in case they help, it seems that there are no remains of sack. I have already rotated several times from the hole in the grip section, but as much as it turns, it seems that it is not advancing.

Edit: after some small blows between the hands, this front thread has detached, but still does not come out, it seems that the section is a little narrower than this piece. The rest of the anilos still does not detach from the middle of the barrel.

Edited December 18, 2018 by fountainpen51