A while ago, I acquired a used sailor pen with 21K nib.
there was a tiny scratch below the sailor logo (gold area), so today I attempted to polish that.
As I started polishing, very soon I realized the gold color getting lighter.
to my surprise the gold color was gold plating, not the 21K gold itself.
so I decided to get rid of the gold plating only.
But I was clumsy and some rhodium plating was removed as well, and some gold color showed up.
at this point I decided to get rid of all the plating layers.
To my surprise again, the actual 21K gold was not deep gold color, but a light shampagne color.
As far as I know, this is impossible for typical 21K gold.
So, I think this is platinum based 21K alloy.
This is the back side of the nib.
I think the gold color is also just a plating, just like the front of the nib. <--- I verified after, and indeed it is gold plating.
This is the nib with all the plating layers removed.
some rhodium plating is present at the root of the nib.
Unfortunately, this is a bad news for custom pen makers such as I.
Since the nibs are usually secondhand, I usually remove minor scratches present on the nib.
Such polishing work is almost impossible for Sailor 21K nibs, as the plating layers are too thin.
I think from now on, I will leave the scratches as is.
Or I could attempt micro-hammering technique, but still seems quite risky.
(might be possible with the utmost delicate care)
another option is to remove all the plating as shown above, although this requires a lot of effort.
I hope my findings help those attempting to polish the nib.
