Mb Turning Knob Will Not Budge

[Marcwithac]

I have a vintage Monblanc 236 that I was using as a daily writer until a few months ago. I went to flush and refill it today and could not get the turning knob to move. It previously took some effort to turn, suggesting that the current cork was a bit on the tight side. Does anyone know an easy hack to unstuck it?

[Marcwithac]

Sorry about the double post. Not sure how that happened.

[Paul80]

Hi

 

I suppose it depends on why it's stuck, is it the cork stuck to the barrel or the telescoping piston stuck.

 

Problem is to fix it you will have to remove the section and or the piston knob assembly and IIRC on these pens both are press fit and the barrel can be quite fragile, gently dry heat will help but a cracked barrel is often the result.

 

You could try pull the nib & feed then soaking the piston with water through the section.

 

Await dome more advice before proceeding.

[siamackz]

Heres what I would try (for whatever its worth):

1. Force water into the barrel by placing the nib up under reasonably strong pressure running water.

2. Once water gets in then I would hold the pen nib up and make sharp but short turns of the piston back and forth just to get the cork slide over some water. This should then help it move

3. Of this works I would then open and file down the cork

 

An alternative would be to open the section and with a sharp pointy pick just start tearing up the cork while its stuck in the barrel

[Marcwithac]

Thanks Paul80 and Sia. I will try to force water into the barrel through the nib and feed (which are not clogged) and see if I can get it loose.

[fountainbel]

Hi mrp100,

Hope you were able to get the piston working again.

But don't force the piston movement when the piston is still stuck as you may damage the telescopic filler mechanism.

The telescopic filler unscrews from the barrel (RH threads) normally the threads are not shellacked so applying some torque you should be able to get the filler completely out from the back and sand the cork a little off.

If the pistons still strongly stuck you will have the remove the the nib unit and after unscrewing the filler you can push the filler out from the front using a dowel pin as large in diameter as possible.

Applying some force to drive the piston out will not damage the telescopic filler.

Wishing you succes !

Francis

[Marcwithac]

Thank you Francis. I have not been able to free the piston and will try your approach. One question: when I screw the telescopic filler back in, should I apply any kind of sealant?

[fountainbel]

Thank you Francis. I have not been able to free the piston and will try your approach. One question: when I screw the telescopic filler back in, should I apply any kind of sealant?

 

 

If the piston cork seal is still tight you can apply some pure vaseline on its outside

But probably you will have to make and install a new piston cork, clean / grease the telescopisch filler and clean the barrel in a Ultra sonic cleaner

Ideally the cork should have 0.15mm radial pretension in the barrel bore.

The cork should preferably be soaked in parafine after finishing .

Francis