There are a few common mistakes made by people oiling their baseball gloves.
Overdoing it. Applying more oil than necessary has some drawbacks. It can add unnecessary weight to the glove making it more difficult for the player to catch and release the ball. The leather as a limited capacity to absorb the oils applied. If more oil is put on the glove than necessary, it will just sit on the top of the leather and possibly turn gummy, sticky.
Heavy oil or grease. Certain products like vaseline are thick and will not easily penetrate the glove. It requires a lot of massaging action to push it into the leather fibers. Most of it will just sit on the surface making to glove more difficult to handle.
Wrong type of oil. This is the biggest mistake people make. A lot of ball players use glove oils made from mink oil or neatsfoot oil. The issue is the potential for rancidity. Here’s a perspective from a knowledgeable expert in leather.
The oils break down. When oils are exposed to oxygen and heat, they break down into smaller molecules. These smaller molecules can react with each other to form new compounds, some of which have unpleasant odors and can cause the leather to become brittle.
The leather fibers become damaged. The breakdown of the oils can also damage the leather fibers. This can make the leather less flexible and more likely to tear.
The leather loses its moisture. Rancid oils can also draw moisture out of the leather, which can make it dry and stiff.
As a result of these changes, the baseball glove leather can become:
Brittle. This means that it is more likely to break or tear.
Stiff. This means that it is less flexible and can be difficult to use.
Dry. This means that it is less comfortable to wear and can crack or split.
If you want to prevent your baseball glove leather from becoming rancid, you should use oils that have a low iodine value. The iodine value is a measure of how easily an oil will oxidize and turn rancid. Oils with a low iodine value, such as coconut oil and beeswax, are less likely to turn rancid than oils with a high iodine value, such as olive oil and mink oil.
The lower the number the better. Here is a ranking of baseball glove oils according to their iodine value:
Mitt-Spit glove oil: 1
Coconut oil: 9
Beeswax: 7
Avocado oil: 8
Olive oil: 85
Neatsfoot oil: 75
Mink oil: 80-95
As you can see, Mitt-Spit glove oil has the lowest iodine value and is therefore the least likely to turn rancid. Coconut oil and beeswax also have low iodine values and are good options for conditioning baseball glove leather. Olive oil, mink oil, and neatsfoot oil have higher iodine values and are more likely to turn rancid.
You should always store your baseball glove oil in a cool, dark place. You should also avoid using your baseball glove in wet or humid conditions, as this can accelerate the oxidation process and cause the oils to turn rancid more quickly.