Otari MX-5050 BII capstan shaft cleaning

[juanfz]

I'm new to reel to reel decks, recently I got an Otari Mx-5050 BII,  everything  works fine but  I can not remove some hard black material adhered to the capstan shaft , as it is on the outer side of the tape path it does not seem to be from tape material but from pinch roller (pinch roller is not worn) . I have tried using alcohol with no success, don't want to use sandpaper or something abrasive.
I would like to know how to clean the capstan shaft.
Thanks   

[ironbut]

Hi Juan,

Welcome to the forum.
If the black material is on the section of the capstan that contacts the tape, it could be from using a sticky tape. It usually appears as clumps or specks.
That stuff is very difficult to remove and if it's been on there for a long time, alcohol hardly puts a dent in it.
You can try using something like naptha which can usually be found at the hardware store. Even with naptha, it isn't easy to remove. Just be careful not to flood the shaft and have the cleaner drain into the bearings inside.