he care of an antique sword is very different from the care of a reenactment sword or even a good quality cutter. This page is about sword conservation rather than restoration. Restoration of one of these swords should be left in the hands of an expert. It's too easy to mess it up, and then, a piece of ancient chinese weaponry is left permanently damaged.
First, take a look at some of these ancient Chinese swords, to get an idea of what we are talking about. The word "antique" implies something is at least 100 years old.
Restoration of an antique sword.There are a variety of views on how much we should touch an old sword. From the viewpoint of a collector, we should do as little as possible - just conserve the sword from any future damage so as to keep the highest possible value. From the viewpoint of a martial artist, the sword needs to look reasonably good and be useful for forms and daily practise.
Whatever your leaning, there are some important considerations. We would all agree on not doing anything that would damage the sword. Restoration - anything that involves disassembling or reassembling an antique sword, should be left in the hands of an expert. Philip Tom, of California did mine. It went to him as a blade with no hilt or fittings and no scabbard. A set of antique fittings from another sword of similar age, went with it. Philip cleaned up the blade. I asked him for a medium polish so that the sword was sharp, free of all but the deepest rust, and was shiny again. This would be too much for some people. I see my sword as a work of art that deserves to look its best.
Philip made a new hardwood handle for my sword from wood that had seasoned over the years and was similar to what it might once have had. He made a keeper scabbard for it with no fittings. I don't want any until a set of antique scabbard fittings that match the style of the sword, can be found.
He also put the antique guard and pommel on the sword. They are brass and I had them cleaned but they won't be cleaned again. They will be left to naturally patina with age. Those parts of the swords weren't really intended to be shiny.
If you want a sword you can handle more and take less care of, buy a modern reproduction. You'll need one of those for your training anyway.
The best oil for a nice old sword is a light, non-acidic lubricating oil. Choji, made from this type of oil with some clove oil in it, is my favourite. I love the smell. Camellia oil is another good one and so is magnolia oil. These are proven products for antique sword blade protection. They are mild enough not to damage the non steel parts of the sword, although you would try not to get them on anything but the steel.
If you use a white cloth, there is no danger of dye bleeding onto the sword. I use very well washed old cotten cloths. They don't bleed even if they are coloured. They were washed too often over the years.
Something most people don't think of is leaving the sword to someone sensible in your will. An antique sword will outlive you. Make sure it isn't left to rust when you are gone. Leave it to someone who wants it and knows what to do with it, even if that person isn't a family member.