Unable to unscrew M800 nib

[Shoko]

I have an m800 (dated 1997-2003) that is generally in a great condition, however I am unable to unscrew the nib unit. 
I cleaned it thoroughly and let it soak in lukewarm water for a while before trying but to no avail. I don't want to apply more pressure than I already do (for comparison my modern m400 easily unscrews with less force used) since I am pretty sure it's just dried ink stuck and I just need to get it out before trying again. 
Also the nib has permanent ink stains that won't get off (I suspect the ink is either red or purple 4001) but that's not a priority to fix atm. 
your help would be greatly appreciated, thanks.  

[lionelc]

soak and soak again, perhaps a little run in an ultrasonic cleaner

[Karmachanic]

Rapido-Eze may help

[PAKMAN]

If the piston is functional, draw in and dispel water multiple times to try to help clean out ink along with soaking. 

[Shoko]

On 5/16/2024 at 11:26 AM, lionelc said:

soak and soak again, perhaps a little run in an ultrasonic cleaner

 

On 5/16/2024 at 7:16 PM, PAKMAN said:

If the piston is functional, draw in and dispel water multiple times to try to help clean out ink along with soaking. 

 

I actually have an ultrasonic cleaner on the way, how would you go about cleaning it using the cleaner?

[PAKMAN]

I wouldn't put the whole pen in the ultrasonic, just the nib and section. Some folks put a little ammonia in the water to help the process. Also to keep the ultrasonic from getting full of the ink sometimes I use a small jar with the ammonia water mix in it and sit it in the ultrasonic with water around it. 

[Shoko]

26 minutes ago, PAKMAN said:

I wouldn't put the whole pen in the ultrasonic, just the nib and section. Some folks put a little ammonia in the water to help the process. Also to keep the ultrasonic from getting full of the ink sometimes I use a small jar with the ammonia water mix in it and sit it in the ultrasonic with water around it. 

So I have to get the nib out before using the cleaner anyway, I will try again when I get the cleaner. 

[PAKMAN]

I just stand the pen up in a cup nib down to soak or when I put it in the ultrasonic.

 

[Mercian]

On 5/16/2024 at 8:28 AM, Shoko said:

I have an m800 (dated 1997-2003) that is generally in a great condition, however I am unable to unscrew the nib unit. 

At the start of this year I bought a Pelikan 400 that was made in 1954.

When I bought it, its nib unit would not unscrew.
It has one of the ‘fragile’ ebonite feeds under its nib, so I really didn’t want to try to force it to move.

 

After reading some old threads on here, I drew plain tap-water up into it, and left it standing in a glass of plain tap-water that was filled to the depth of the black part of its grip section (i.e. not so deep that the green-striped cellulose-acetate body was submerged).

 

After three days standing in plain tap-water at room-temperature, my 1954 Pelikan 400’s nib unit unscrewed really easily 😊

I advise you to flush your M800 by cycling plain tap-water into it and out of it again several times, and to then;
stand your pen in a glass of plain tap-water, with the water deep enough to cover the black part of its grip-section, but not deep enough to submerge any part of its striped body (or ink window), then;

leave it there, for a few days.

Capillary action should dissolve any old ink that has dried out on the threads and ‘gummed-up’ the nib/feed-unit’s threads.
Check it after two days, and after three days, and after four days, and after five days (if necessary).

 

You should find that the water dislodges any old ink residues, and makes unscrewing your pen’s nib/feed really easy.
If this approach doesn’t work, please post here to let us know, and I can then give you some advice for a ‘next stage’ of safe practice to ensure easy disassembly.

 

Good luck 

 

Slàinte,

M.