Broken Feed Tube Repair

[PBobbert]

A while ago I wrote a post about feed problems I was having with a pen of mine. I had mistakenly miss-diagnosed the problem associating my feed issues with either a clog or sprung tines. I spent a lot of time monkeying around with the nib. Admittedly, some of the things I have done to this nib seem embarrassing looking back on them. But I guess you have to make mistakes to learn.

 

At the time I had actually correctly identified the symptom as

Upon closer inspection what seems to be the problem is that while writing the nib seems to (from pressure) move to far away from the feed, and ink stops wicking to the tip

 

 

But the actual problem was that my feed tube had, somehow, cracked in half! The result was that the feed tube would bend down away from the nib which prevented ink from wicking to the tines. Since the time of the first post the problem had gotten much worse; I haven't been able to use my pen for over a year now. But today I have finally fixed it.

 

Pictured in photo 2 and 3, you can see the completed work. I wish I had taken more photos along the way, but most of this repair actually happened eight months ago. Procrastination took the rest of the time. The white plastic marks where the crack happened, along the top surface perpendicular to the axis of ink flow.

 

To properly fix it, I had to cut the tube entirely in half with a blade by rolling it very slowly to produce a very clean cut. The break happened right where the comb started. After cleaning the surface, I chose to sacrifice one segment of the comb to increase the gluing surface area. Having shaved and filed off all the nearby damaged plastic, I inserted a shim of white polystyrene to return the feed tube to its original length.

 

Then came the most difficult step, pinning. Here is where I really wish I took photos. To ensure the final product would not break again, I pinned the two halves back together (and the white polystyrene shim). I used two pins so that they would best bear forces in the direction of the original fracture. The steps were to glue the shim to one side (the rear) and then drill two holes through the shim and into the rear segment. The most difficult step is the next one in which you must drill two matching holes on the front half so the halves line up. The assembly is glued together with loctite 380 rubberized superglue, which is flexible when cured to best resist stress.

I also had to repair the back feed tube collector, which I had damaged at some point or another long long ago trying to remove the tube from the section. For future readers, do not try to push the feed out via the collector or you will need to do what I did and replace it. I ended up cutting off the original collector and fashioning a new one out of plastic sprue I had laying about. This is also pinned. I use staples for pins, they work fantastic.

 

Lastly I just had to clean the glue out of the feed path, and then re-assemble the pen.

 

It writes very well now. Ink flows quite well, and with my new microscope I re-aligned the tines. Admittedly some of the damage I caused to the nib is beyond my skill to repair. I have effectively turned this Fine nib into a Medium. There is also a small tear forming at the base of the breather hole. I may pursue experience professional help to fix up the nib.

It was quite a nice feeling being able to write with my old pen again.

[siamackz]

That is a very clever restoration. If there were a way to fix broken feeds, then Id expect this to be it. I tend to write off broken feeds and look for replacements. I am curious if the glue will hold over time given the feed is constantly under stress while writing. Have you been using it regularly for 8 months?

Thanks for sharing this excellent work!

[PBobbert]

Thanks! Yes sadly this pen is out of production, I tried to get another feed but I could not find one. No I just finished the collector repair and put the pen back together this morning. I did the first half of the repair back when I didn't have a microscope.

 

Im curious how long it will last too. I have some new adhesives I will try if I do need to make amends. Although the pins are really the thing holding it together. I remember thinking that I almost didn't need to glue it when I first did the repair. The glue is mainly to hold the assembly together while putting it into and taking it out of the section.

[Inky.Fingers]

Pins are great. They put pins into a broken tooth when there is no other choice, it works. No worries

[Bibliophage]

Staples being used as pins are really good - except they tend to be very low grade steel, which will very quickly rust when exposed to water. I've done similar, but only for a temporary 'fix' on something I was gluing.

 

I don't know if they make stainless steel staples or not. I've never thought about it.

[PBobbert]

Staples being used as pins are really good - except they tend to be very low grade steel, which will very quickly rust when exposed to water.

 

 

Hmm that is a good point. If the time comes when I need to upgrade the joint what would you recommend? I chose staples because they are very stiff for their diameter.

[siamackz]

Pins are great. They put pins into a broken tooth when there is no other choice, it works. No worries

I understand now. Makes sense. But how are the pins placed? Even a diagram would be very instructive if the OP finds the time of course Edited March 2, 2020 by siamackz

[Bibliophage]

 

 

Hmm that is a good point. If the time comes when I need to upgrade the joint what would you recommend? I chose staples because they are very stiff for their diameter.

I _think_ that a staple is 23 gauge wire. So you could buy a spool of 23 gauge stainless steel wire. (or titanium)

 

Now you have me wondering. I'll have to grab my calipers and check some of my random different kinds of staples.

[bsenn]

On HO slot cars there are race classes which allow drilling and pinning to reinforce weak areas and/or repair weak areas. An example is the pickup shoe tabs which stick out the front of the chassis. We drill those and put a rod in as part if chassis setup before they break. I tend towards 0.025" steel, but brass also works.

 

I have used this method to repair various items ranging from toys to car trim and cover pieces. Holds up very well.

 

Brian

 

Edited: fat fingers

[Anderglan]

That's a cool MacGyverism!

 

Staples being used as pins are really good - except they tend to be very low grade steel, which will very quickly rust when exposed to water. I've done similar, but only for a temporary 'fix' on something I was gluing.

 

I don't know if they make stainless steel staples or not. I've never thought about it.

Yes, they make -- you could ask the staff at your State's Archive what kind of staples they use for their long-term-archival files, then you can be quite sure it's the most durable, stainless-est, sort of staples.

[PBobbert]

I went ahead and checked with my own calipers, staples are 0.019" x 0.016" rectangular in cross section. I have been using them for small modeling pinning for a while now which is why I defaulted to them for this project.

 

I think that a staple is 23 gauge wire

 

Looks like 24 or even 25 might be closer, but really a pin should be sized for your task at hand. Either way a person is going to need a drill index and a pin vice. I have a 61-80 Huot index which I love.

 

Here is a diagram (drawn with the pen I fixed of course) illustrating the pinning.

[siamackz]

I went ahead and checked with my own calipers, staples are 0.019" x 0.016" rectangular in cross section. I have been using them for small modeling pinning for a while now which is why I defaulted to them for this project.

 

 

Looks like 24 or even 25 might be closer, but really a pin should be sized for your task at hand. Either way a person is going to need a drill index and a pin vice. I have a 61-80 Huot index which I love.

 

Here is a diagram (drawn with the pen I fixed of course) illustrating the pinning.

Thanks so much for sharing. This is very instructive