Here is a fact of life: some metals will rust. In the case of yoyos, although the yoyo won’t rust, the bearing it comes with can, and possibly will. However, there are ways of preventing your bearing from rusting and if it happens, there are ways to remove it.
|This is what a rusted bearing looks like.|
The simplest way to prevent rust is to store the yoyo properly. After playing with their yo-yo, many players will just wind the string back, and leave the yo-yo like that. This is fine. However, as players may have sweaty palms, the country you live in may be humid, etc, we would recommend the yoyo be stored with the string off. This is because the string absorbs moisture from the players hand and moisture on the string will speed up oxidation, causing rust on the bearing.
|Storing the yo-yo without string: Recommended!|
|Storing the yo-yo with a wound string: Not recommended.|
On that note, another way to prevent rust is to store the yoyo in a dry place. For example, leaving your yoyo in the bathroom while you are taking a steaming hot shower is not a good idea. Neither is in the kitchen next to a pot of boiling water. Also, lubing a bearing after washing it will form a barricade between the metal and the air, so that too will help fight away the rust.
Is it too late? Do you already have rust? No need to worry! Sanding the bearing will help to remove the rust. Be sure to use a fine grain sand paper, and rub it on the bearing. After you are done with the sanding, make sure you clean your bearing thoroughly.
|Begin with fine grain sandpaper.|
Another thing to keep in mind is that it is perfectly natural for a bearing to tarnish(or turn black). If this happens, there is no need for sanding and you should be able to play it as normal.
|A tarnished, but properly kept bearing.|
If this is all too much for you, there is another solution. You could replace the bearing that your yoyo comes with, to a Stainless Steel EZO bearing. Stainless steel does not react with oxygen, so it will not rust.
EZO Bearing Large/Medium: SGD$8.90
EZO Bearing Small: SGD$7.90
If not, you could always consider other forms of bearings like:
Dif-e-yo Ceramic Konkave Bearing Large/Small: SGD$49.90
Dif-e-yo Konkave Bearing Large/Medium/Small: SGD$24.90
Central Bearing Co. Centre Trac Bearing Large/Small: SGD$17.90
OneDrop 10-ball Bearing Large: SGD$15.00
All of these are Stainless Steel as well!