removing clear varnish from a old blade

[gp]

Originally Posted by milandro

(why do people do this? )

in many collectors fields (like ancient coins, jewelry or other products from metal;either base metal or gold and silver of a lower degree; i.e. < 500 ) one does not clean the metal as is done with blank weapons by chemicals (other than vaseline, natural oils and the likes ) as it decreases the value considerably.
One lesson I learned when collecting blank weapons and a huge difference with regards to value and cleaning an item . Not talking about patina.

Specially metal which is easily vulnerable to oxidation like iron or zinc.
In that case, dirt is cleaned by using vaseline/ oil or wax and for protection transparent nailpolish or similar varnishes are used as they protect the metal and do not effect the value. Hence I think some use varnish as a kind of protection against oxidation...