Mb 136 Piston Knob Not Retracting When Closed

[Stylomeister]

I have 136 I recently acquired with what looks like a working brass and BHR piston assembly that won't close once the piston has wound its way to the top.

 

I'm not going to try and force this to close and compared to a later mechanism other than the plastics used it appears identical, that is to say nothing obvious appears to have sheared off or is broken from what I can tell.

 

I have a feeling I need to disassemble this to get inside the end to see what is preventing it from closing.

 

Does anyone know how these come apart - I'm assuming they are not designed to come apart and suspect this isn't going to be an easy job.

[Stylomeister]

Photo attached of properly working mechanism and non-closing mechanism.

[zaddick]

Here is a diagram on the piston from fountainbel

 

https://www.fountainpennetwork.com/forum/topic/303978-1950s-m-b-149-sumgai-some-questions/?p=3559668

[slippery when wet]

Good luck with the repair and let us know how you get on

[fountainbel]

I have 136 I recently acquired with what looks like a working brass and BHR piston assembly that won't close once the piston has wound its way to the top.

 

I'm not going to try and force this to close and compared to a later mechanism other than the plastics used it appears identical, that is to say nothing obvious appears to have sheared off or is broken from what I can tell.

 

I have a feeling I need to disassemble this to get inside the end to see what is preventing it from closing.

 

Does anyone know how these come apart - I'm assuming they are not designed to come apart and suspect this isn't going to be an easy job.

Hi stylomeister,

The slipping clutch threads look to be frozen or blocked.

i would try allowing to seep a few drops of WD 40 penetration oil in the seam between the filling knob and the housing.

Getting the filling knob off is a real pain in the neck ! Heat, soaking and... a lot of patience and you may have luck !

The left hand threads in the the filling knob were secured by Montblanc with a special product which becomes stone hard after decades.

Good luck !

Francis

[Stylomeister]

Hmm. Being BHR makes it all the more difficult. I may apply some duct tape to the body and put this into the ultra sonic cleaner and then try some WD40.

 

This Piston when I received it was thoroughly lubed but I'll see where we go with this approach first.

 

Oh, and thanks for the diagram, I did spot this last night and was trying to figure out from it what I need to turn or open to get the spiral and tube out of the knob mechanism without breaking anything.

[fountainbel]

Hmm. Being BHR makes it all the more difficult. I may apply some duct tape to the body and put this into the ultra sonic cleaner and then try some WD40.

 

This Piston when I received it was thoroughly lubed but I'll see where we go with this approach first.

 

Oh, and thanks for the diagram, I did spot this last night and was trying to figure out from it what I need to turn or open to get the spiral and tube out of the knob mechanism without breaking anything.

Hi Stylomeister !

Unfortunately lubing the telescopic filler does not guarantee the slipping clutch gets lubed….

The diagram link attached by zaddick - thanks zaddick !- shows the improved telescopic system used on the 14X pens.

Contrary to the 14x system - which allows disassembling the filling knob with a fork tool after opening the filling knob - on the 13X pens the slipping clutch nut is mounted "blind" and hence very difficult to remove.

On the attached diagram you can see the specific set-up of the 13X range of pens.

Don't be afraid to use WD40, I do this often and never experienced any problem neither on BHR nor celluloid.

Wishing you success !

Francis

 

http://i62.photobucket.com/albums/h89/fountainbel/Repair%20suggestions%20to%20forum/P1010028.jpg

[Stylomeister]

Hi Francis

 

It's good to hear from a true piston disassembly 'meister' :-)

 

I'll give this piston a good squirt of WD40 later today when I get home and will leave it for a few hours and see what happens and report back. If this doesn't work it looks like I'll need the help of an expert before I do something daft.

 

Kind regards

 

Julian

[Stylomeister]

Francis, you are a genius - the clutch has indeed resolved itself with WD40!!! :-)

 

As much as I'd like to attach a photo, FPN isn't letting me right now (sigh).

 

All I need to figure out now is how to get this BHR to a darker shade but there isn't much we can do here I suspect.

 

Kind regards

 

Julian

 

 

[Xof72000]

Francis, you are a genius ...

 

 

 

 

 

That is allready known !!

[zaddick]

Francis, you are a genius - the clutch has indeed resolved itself with WD40!!! :-)

 

As much as I'd like to attach a photo, FPN isn't letting me right now (sigh).

 

All I need to figure out now is how to get this BHR to a darker shade but there isn't much we can do here I suspect.

 

Kind regards

 

Julian

 

 

There is a pen blackening product but it is a non-reverseable coating. It will look black again but will never be original. I am not aware of another successful, non-harmful manner to get a bhr pen back to black. If there is I am interested too.

 

I guess urushi coating would work.

[fountainbel]

Gradual oxidation of hard rubber happens to be inherent to the material.

Polishing BHR regularly with with a Selvyt polishing cloth does wonders.

When the oxidation is pronounced , Micro gloss polishing paste and afterwards polishing with a dry Selvyt cloth will restore the original shine,

Rubbing the pen in with a light film of flaxseed oil (or olive oil ) leave it overnight and then rub-off and polish with a Selvyt cloth will delay the risks of oxidation.

Micro gloss can be found on Ebay, the Selvyt cloth on Ebay UK.

Hope this helps !

Francis

[Stylomeister]

Zaddick

 

There is pen potion #9 from Pensbury Manor which is non-permanent but it's like a thin film and will scratch off in time. If there are no impressions then a nail file and some polishing works but this is not often the case for BHR where there is chasing or impressions.

 

I've used a little French polish on red ripple in the past and have had good results, its also not as brittle as a thin varnish based colouring and is also reversible with meths though that also tends to dry out the hard rubber.

 

Also nail buffers work well to bring bring the shine (much cheaper than micro mesh and work for nib tuning) followed with some wadding or similar polish.

 

Francis

 

I think I'll take a look at that Micro Gloss though as that sounds like what I might be after :-)

 

Also a light curing oil sounds worth investigating for lower maintenance so long as the BHR discolouration is minimal. I have a few bits of oxidised BHR lying around from parts pens I think I'll try this with and various oils including Danish, tongue and linseed I use for woodworking as well as olive and rapeseed I use for cooking I can try out.

 

Julian

Edited February 10, 2016 by Stylomeister

[Stylomeister]

OK, seem to have some ink discolouration on my casein star - a little greenish. I could set this and polish it down, just not sure how the edges will come up.

 

Anything useful to remove this - bleach is probably a little extreme I think but would certainly take the colour away!

 

Still can't post any new images...

[KAC]

Excellent and informative series of postings. If you find a cure for the discolored star, do post it, please. I have the same pen and that's a recurring problem for me.

[Stylomeister]

Still can't upload any files so will need to wait until I get some more 'credits' and post some pictures when I can.

 

After reading through this paper from Cornell University of all places I got a few ideas on how to approach the problem.

 

http://www.human.cornell.edu/fsad/outreach/upload/removingstains.pdf

 

Starting off with simple techniques like soap and water and gradually and carefully moving up to mild abrasives like toothpaste and solvent like alcohol. What I found to be particularly effective was carpet stain remover in this case which was able to dissolve the most stubborn portions of ink and mildly oxidise what is essentially stained without ruining the carpet or in my case the casein.

 

When I have some more time I'll drop this into the ultra sonic cleaner and see if that helps with the residual staining and lastly apply a last short soaking in 'Vanish' before setting and polishing the surface in-situ.

 

The star has noticeably and significantly improved and has not begun to break down and disintegrate - it's a relatively mild cleaning formula designed not to ruin carpets and should not be left for any extended period of time.

[zaddick]

Great info Stylomeister. thank you for sharing.

 

The pensbury manor stuff is good for it's intended purpose. I was also remembering a non reversible coating process that I don't think is available any more. No reason to worry about a product no longer available that was controversial.

[Stylomeister]

That would have been the so called G-10 process. I believe people repaint vintage Ferraris and carry out restorations on great masters but fountain pens is a different ball game ;-)

 

I'm going to take a look at adding a colouring agent to some curing oil and see where that goes. The nice thing with G-10 was it impregnated the material apparently and no doubt preserved it too - but anyway as you said... shrouded in controversy with much heated debate and now no longer available.

 

If there are no impressions or chasing the most effective solution is a nail file and buffer; it polishes up like new :-)

[Stylomeister]

Thats annoying - after posting a 66K file I seem to have used my lifetime limit. I had one more to post of the cleaning and the restored star, reset into the cap.

[slippery when wet]

Try using the upload tab at the top of the page. There is no restrictions in doing so