Nikon AF-S Nikkor 300mm f/4D IF-ED - fungus cleaning

[mfilippa]

Thank you Richard,
yes I do read your articles, that are useful, and also an enjoyable reading!
At the end it came off with alcohol, I put it from behind with the lens standing, the front end downwards; so the third group was rather close and into a confined space, and it is a cemented doublet, so I avoided more powerful solvents.
Yesterday I managed to unscrew also the 4th and last group, with another tool (as you say, made from scrap )
So now I can go forward and clean the elements...

[mfilippa]

OK, I did it
The fungus is gone with ammonia + peroxide, no trace left on the coatings
I reassembled the lens and shot some photos, it works!
I have not been good enough to clean completely every element, shining a light through the lens many particles are visible. I'll practice in some manner then I'll clean it better.
For the moment I enjoy this revived great lens!
I'll ask help again for a couple of minor issues, but for today... She is our family's Golden Retriever with the AF-S 300. 1/1000 sec, f/4, hand-held.

[Nasos Kosmas]

It’s a very nice lens, congrats you succeeded !

[mfilippa]

Thank you Nasos!

[mfilippa]

I complete the story of disassembling of this lens with an image of the tool I made to unscrew the 4th lens group. It took maybe 10 minutes to do. Just a little of alcohol in the thread around the 4th group, and it worked at first attempt!
The lens group tends to remain attached to the double-sided tape, but it's somewhat dangerous to pull it away like this. So it's better to unscrew just a little, then extract the tool and finish unscrewing with the rubber sucker and remove the group.

[mfilippa]

This is the first of the two minor issues.
The built-in hood is becoming loose in these lenses because the only thing that prevents it from moving freely is a small strip of felt or velvety tape, located at inside of the hood at the rear end.
In the drawing it is in section, with orange circles, part n° 117.

[mfilippa]

This felt becomes easily worn with time and use, that's why the hood become loose.
In dismantling the lens I had to use a lot of alcohol to unscrew the first lens group and soaking this felt is unavoidable.
The alcohol melts the glue and the felt breaks down in pieces.
Obviously the hood after reassembling seems most of a bell on the lens (when not secured full extended).
What kind of material should I buy to to replace that felt?
(Richard, I don't have milliners or hatters around me...)
Thanks