Taking Apart/repairing Plunger Filling System Of Wahl Doric

September 16, 2010

I have some experience with some filling systems but I have never taken apart a plunger in general and a plunger in a Doric in particular. The section unscrews and I washed the barrel inside and out. It is very beautiful and with a nice transparency. This is the type of plunger that screws in at the end of the barrel. It moves freely, but when I pull it out, then submerge fuly nib in water (or ink) and I push the plunger in, nothing at all happens. I think no vacuum gets created. There are two issues then, first I need to take it apart and second I need to repair it....

Do I need any special tool? Under the end of the blind cap, there is what appears to be a little nut and maybe if I can unscrew that the plunger would pull out from the section side? Also, the blind cap screw perfectly at the end when the section is out, but when the section is in I feel some friction and it does not screw in completely, hinting to the fact that migth touch the section and soething over the decades might have shifted?

Any suggestion is welcome and if "Wahlnut the Great" has some chart on the topic, that would be even greater!

I noticed that repairs on Wahl pens are posted here, probably because these pens are much less standard and standarized than the pens of the other brands. It appears to me, Wahl newbie, that Wahl was ahead of the pack tin echnical advances for the time.

September 17, 2010

Well, to be done correctly, "plunging" into a topic like this one would require a 1 hour practicum in the Pen lab at least. To do the kind of repair that will get you to 80% plus fill on the one downstroke that was the factory fresh norm, takes a lot of experience in my opinion. Having said that, the concepts involved are simple physics and the components that enable the physics to work, are not terribly weird or complex. Getting them to work together and be in proper spatial relationship to one another and tuning them in small increments to get there...ah grasshoppers that is the difference between science and art.

First, you are correct that the vacuum generated by the downward plunge on the piston is created by an air-tight seal around the plunger rod at the rear of the pen and the plunger disc (gasket) at the head of the rod. In order for the vacuum to happen, both the rear seals(stacked 2 felt and 3 rubber with a graphite one inside the "stuffing box" and the gasket at the head of the plunger must in near perfect condition. To repair the filler system requires that the repair person can do that. Yes, the little locking nut at the rear end of the plunger rod holds against the bind cap to keep it from coming off. It also fine tunes the depth of the plunge which is critical to the fine tuning process after the pen has had its innards renewed, The head gasket and rod tip need to end up in the exact right place at the end of the fill stroke. Inside the rear of the section is a section pin that forces the rounded and tapered head of the plunger rod off to one side ensuring the break in the vacuum right at the end of the rods plunger stroke, which is filled by ink that rushes in through the feed ink channel, and past the plunger gasket that has been pushed aside by the section pin and into the barrel to fill the void. I could literally write 20 pages on how to do the restoration, but suffice it to say that the determination as to how much needs to be replaced is the first step in knowing how much information will be required. Once you are sure about that, you will know how far into the pen you have to go. Then, getting at the parts involved and renewing/replacing them is the next step.

The repair manual of January 1937 is 17 pages long not counting the matter of the ink shut off mechanism and the adjustable nib. Me thinks it too long to reproduce here. Now if you are planning to become a repair pro, I suggest you invest in one and take the month or two it probably would take the average mechanically inclined person to learn the ropes. David Nishamura (Vintage Pens) sells some substitute parts that have been developed to work around the full restoration of the parts usually involved. For example the stuffing box was originally threaded into the rear of the pen and was sealed with shellac...and that is usually hard, read usually impossible, to get out without damaging the pen unless you have the process down correctly and know when to stop heating the area just before and melting the pen. Besides, the stuffing box threads are reversed and that usually cause the most damage by novices. Davids method involves the drilling out of the fron end of the stuffing box. That front end is actually a threaded disc that goes in before the stuffing box and then the stuffing box is threaded in and the open end of that abuts the disc. Of the probably 300 of these I have done, I ruined about 7 stuffing boxes or pens in the early stages of learning (always learned on my own pens by the way. never a customers.)

If all that is needed is a new front end gasket, then it is within the capability of most people...provided you get the final positions of the renewed parts in the proper place and position. At least for now, here is a diagram that came with instructions for filling in the repair manual in cross section of the construction you are dealing with.

http://i9.photobucket.com/albums/a75/wahlnut/Plunger-Fill-Instructions-1.gif

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

Edited September 17, 2010 by Wahlnut

September 17, 2010

Thank you very much Wahlnut, as always your explanations are outstanding and the literature that you reproduce is great. "The repair manual of January 1937 is 17 pages long"....you suggest to invest in one. I do not plan to become a repair pro, but maybe just to repair the dorics that I will stumble upon in the future...where do you buy one of those? I guess it will be a reproduction.

The first evening that I have some time I might try to at least undo the locking nut. I guess the rod is metal and it screws into the nut. Which tool do you use to grab the nut? Do you undo the blind cap first? Is it even possible?

It sounds like this will be a long repair project for me while climbing the learning curve, but better taking it easy than destroying a 70+ year old pen...

September 20, 2010

I think my questions were not noticed:

1)Where can I buy the 1937 manual?

2)where can I buy the proper wrench to undo the blocking nut under the blind cap? Do I undo first the blind cap and then remove the little blocking nut?

September 21, 2010

I think my questions were not noticed:
1)Where can I buy the 1937 manual?
2)where can I buy the proper wrench to undo the blocking nut under the blind cap? Do I undo first the blind cap and then remove the little blocking nut?

I'm interested in these too...

Simone

September 22, 2010

I think my questions were not noticed:
1)Where can I buy the 1937 manual?
2)where can I buy the proper wrench to undo the blocking nut under the blind cap? Do I undo first the blind cap and then remove the little blocking nut?
I'm interested in these too...

Simone

You can PM me for more information

Syd