Mb 149 Servicing

[Maxpens]

Never, never use Silcon or Loctite if you repair a Montblanc pen, the resin do not like both, after a while you will get a lot of micro cracks.

Eric is right:

"

I'm not sure why you would want to use Loctite. The seal that draws ink is formed by the elastomer seal not the threads of the piston/barrel. If the piston mechanism is installed correctly, it will not "back off" or unthread. There does not need to be any sealant applied to the piston threads."

 

The only thing you need for the piston is Vaseline, Silikon and ink = skipping while writing

 

kind regards

 

Max

[Dutchpen]

hi,

 

i'm not sure what material the piston cup is made of, i think something like a silicone base material, but the cup is very hard except for the sealing edge.

maybe it is made from a kind of plastic or rubber. is there any way to check what kind of material this is made of?

 

Hari317, i think this is what you mean. let's hope this cup isn't made of silicone.

 

Environment aggressions have less effect on silicones if compared to organic lubricants. The oxidation resistance of silicones makes them suitable for long-life applications. Because oftheir inertness to most chemicals, silicone lubricants are widely used in the chemical industry, and also in food and beverage processing. Though the load-carrying capacity makes silicones a candidate for plastic lubrication, it is their inertness with almost all plastics or elastomer materials that makes them ideal in these applications. Poor compatibility is experienced only when silicones have to lubricate silicone elastomer surfaces because of the swelling they induce in the silicone elastomers.

 

 

 

 

I have a modern 146 barrel which i can use to try any kind of lubricant and other stuff on.

i'll drop some of this 243 loctite and some silicone on it and leave it for a while and see what happens.

 

this is the second time that i 'serviced' this mb 149 with loctite 243, it never caused any problems yet and i hope it still doesn't cause problems.

 

 

i use a very tiny drop of loctite to prevent the pistonunit to unthread. The loctite is not for sealing.

 

Maxpens, vaseline is a grease based on Petroleum, i don't think this is good for the piston cup. do you use vaseline for lubricating pistons?

 

kind regards

 

Lennard

Edited September 19, 2010 by lennardvanzwam

[niksch]

The effects of the Loctite or lubricant are not short term problems. I doubt you'll see problems in only a few weeks or months.

 

The long term effects are what Max is talking about.

 

 

I have a modern 146 barrel which i can use to try any kind of lubricant and other stuff on.

i'll drop some of this 243 loctite and some silicone on it and leave it for a while and see what happens.

 

this is the second time that i 'serviced' this mb 149 with loctite 243, it never caused any problems yet and i hope it still doesn't cause problems.

 

 

i use a very tiny drop of loctite to prevent the pistonunit to unthread. The loctite is not for sealing.

 

Maxpens, vaseline is a grease based on Petroleum, i don't think this is good for the piston cup. do you use vaseline for lubricating pistons?

 

kind regards

 

Lennard

[eckiethump]

Never, never use Silcon or Loctite if you repair a Montblanc pen, the resin do not like both, after a while you will get a lot of micro cracks.

 

kind regards

 

Max

 

What is the basis for the modern MB resin not liking silicon ? Loctite use being unnecessary and detrimental I can understand.

et

[Peter of Poland]

Hi,

 

since it was me who started to share some doubts regarding MB substitutes in this thread I feel that I should make some additional comments.

 

I thought that it could be summarized as follows. Silicone grease (e.g. Dow Corning High-Vacuum Grease) or oil are safe for rubber parts and plastics (e.g. I wouldn’t hesitate to use it in my TWSBI pen) but can swell silicone based elastomers (this could be a piston of modern MB 146/9s – not sure about the nature of the used material but it looks like it could be made of silicon elastomer) while hydrocarbon based grease (e.g. petroleum jelly aka Vaseline) or oil are safe for silicone parts but can swell rubber (hydrocarbon based elastomer) and deteriorate some plastics (this could be the MB precious resin).

 

As for a piston thread adhesive, since something is put there by the pen manufacturer it seems reasonable to me to do the same. I think it should prevent unintentional unscrewing of a piston assembly. However, when using a tool it should not require too much force since a plastic barrel could break up into pieces. A very thin layer of a low-strength threadlocker for locking plastics fasteners like Loctite 425 (dark blue liquid) could be more appropriate since Loctite 243 is a medium-strenght threadlocker for metal surfaces and requires much more force for disassembly. However, we know nothing about their compatibility with the MB precious resin. If after a few days they could be completely removed from a barrel without any solvent and leaving its surface untouched I guess they should be OK since they cure in 24 hours and after that time nothing more should happen.

 

A sealant applied to a piston thread could be a protection in case an elastomer seal is broken to avoid an ink leakage out of a pen. I am aware of the fact that ink can migrate freely along a piston rod but at the beginning it should accumulate inside a turning knob. Also, it could be a form of a manufacture warranty seal / tamper-proofing agent.

 

These are just my thoughts and sorry for my simple English.

Regards, Peter

[Dutchpen]

today o took the 149 apart again, the loctite did not caused any problems. the barrel did not break.

 

 

i think silicone does not hurt the any parts except for maybe a silicon piston cup.

silicone is a grease which can be used for plastics, resin is also a sort of plastic.

 

 

 

[vysis]

what type of polish did you use?

[Peter of Poland]

today o took the 149 apart again, the loctite did not caused any problems. the barrel did not break.

 

Hi,

 

that's great news.

 

What was the consistency of the cured Loctite 243? Have you been able to remove all traces of it from the thread inside the barrel?

 

Regards,

Peter

[Dutchpen]

what type of polish did you use?

 

hi,

 

using silver polish works.

after polishing you need to clean it with water to get of the remains.

[Dutchpen]

today o took the 149 apart again, the loctite did not caused any problems. the barrel did not break.

 

Hi,

 

that's great news.

 

What was the consistency of the cured Loctite 243? Have you been able to remove all traces of it from the thread inside the barrel?

 

Regards,

Peter

 

 

 

 

hi,

 

no problems with the loctite, because i didn't use much of it there were almost no remains of it.

the loctite was hard.

 

still no problems with the silicon or loctite like i expected.

 

Lennard

[Dutchpen]

checked again today, still no signs of damage.

piston still feels an looks good.

[Peter of Poland]

Hi Lennard,

 

Bearing in mind that there are excellent pictures here I have just removed the nib unit from my MB146 and am about to dissemble the nib unit. To do it correctly I have just wanted to look again for same details. To my surprise, I can't find these pictures anymore. Is there a place I can find them? I look specifically for a picture showing how to assemble a nib unit back (to put a nib, feed and collar together).

Thanks, Peter

[soapytwist]

I look specifically for a picture showing how to assemble a nib unit back (to put a nib, feed and collar together).

Thanks, Peter

Not sure if these photos will help:

 

My link

 

 

Try asking on the MB Forum - I'm sure someone will post some clearer photos for you.

[watch_art]

If you want to get them apart, put the collar on a knock out block with the nib pointing down, and use something as a punch (I use kabob stick) and a small hammer to tap the feed and nib out of the collar. When you put it back together, just besure the nib and feed are lined up nicely, pinch em with thumb and forefinger, make sure you've got it lined up to go back in the collar in the right spot (the nib should be where the nib indention is) and shove it in. You may want to warm the collar up in hot water or with some hot air first to expand it a little, to make it easier to put back together. It's basically just like a Pelikan nib unit, or the nib units for TWSBI or Levenger pens. Only bigger.

[fountainbel]

Important question is : do you really need to knock the feed/nib out of its housing?

 

Using an ultrasonic you can obtain a perfect cleansing of the assembled nib unit.

 

The only reason I knock the feed /nib out is for exchanging the nib, otherwise I always US clean the complete nib unit.

 

One can only use a classical nib block for knocking a MB feed trough when the nib unit is still mounted (screwn) in the section.

 

In this situation the diameter step between the “ nib wing diameter “ and the section front diameter is large enough to provide a good back-up

 

Only poissible drawbacks are the knocking forces will react on the threads, and one has to screw the threaded housing out separately.

 

A conventional nib block does however NOT allow to knock the nib/feed out from a disassembled MB nib unit.

 

Reason being the collar diameter of the nib bushing is (nearly) identical to the nib’s "wing width diameter".

 

So when introducing the nib though the narrowest nib block hole the bushing will also fell through.

 

One could use a conventinal nib block when making additional special slotted washers for the different MB nib unit sizes.

 

Reassembling the nib unit is also rather difficult because Montblanc - avoiding any leakage risks between feed and bushing- really uses a thight (nearly press) fit.

The wall of the bushing being also rather thick one can't slide or "shove" the feed/nib in that easily.

Heating the bushing sometimes helps but not always

In most cases I use my nib assembling tool in which one clamps the nib and feed and carefully knock the bushing over.

Francis

[watch_art]

my knock out block is sort of a rubber material, so the nib fits and the collar stops.

[Peter of Poland]

Thank you all.

 

Francis, you are right I would like to clean a feed and nib, so first I try to use an ultrasonic bath with the complete nib unit as you have suggested. I hope it really helps. Never have done it before. Any suggested settings like time etc? You also seem to be the right person to ask how to use beeswax for mounting nib assembly back into a barrel. I guess one should melt it at approx. 70C and ...?

 

Under these circumstances, lack of pictures seems to have saved my nib assembly. Otherwise, it would have been already dissembled and now as I see it would be a real problem to put these parts together.

 

Peter

 

EDIT: I removed some language errors

Edited February 27, 2011 by Peter of Poland

[eckiethump]

my knock out block is sort of a rubber material, so the nib fits and the collar stops.

 

I'd be interested in seeing pictures of this.

et

[watch_art]

my knock out block is sort of a rubber material, so the nib fits and the collar stops.

 

I'd be interested in seeing pictures of this.

et

 

I'll do one better.

Video.

I got it at walmart and it had hammer drill bits in it. The holes are octagon shaped, or hexagon... :hmm1:

Either way, it's perfect for nibs and knocking them out.

 

[eckiethump]

my knock out block is sort of a rubber material, so the nib fits and the collar stops.

 

I'd be interested in seeing pictures of this.

et

 

I'll do one better.

Video.

I got it at walmart and it had hammer drill bits in it. The holes are octagon shaped, or hexagon... :hmm1:

Either way, it's perfect for nibs and knocking them out.

 

 

I hate to see pens broken, what works for you probably wouldn't for most people. Pen repair does take a modicum of investment in the proper tools for the job.

et