Cleaners/solvents are liquids that dissolve and will interact with other liquids to achieve a specifically designed purpose. In some cases, the solvent solution will be employed as a cleaning agent. In other instances, the solvent will permeate a surface and provide a degree of protection. A solvent may also offer a degree of lubrication as well, although this type of solvent usually only lasts for a short period of time.
http://www.wisegeek.com/what-are-the-different-types-of-solvents.htm
I have read that paint thinner, acetone and alcohol work the best and I am going to list the pros and cons of each.
Paint thinner:
Pros
1. It is strong enough to clean out grease.
2. It is easy to find in stores.
3. It is cheap.
Cons
1. It leaves a residue that over time will eat away at the bearings.
Acetone:
Pros
1. It dissolves grease.
2. It is easy to get.
3. Lots of people use it and say it is good.
Cons
1. It does leave a residue but not as bad as paint thinner.
2. CAUTION don’t get nail polish remover without looking at the ingredients to make sure that it is pure acetone.
Alcohol:
Pros
1. It works good and doesn’t leave a residue.
2. It is cheap.
Cons
1. It has to be 95% pure alcohol.
2. It is hard to find.
After all my research, I have found out that acetone or pure alcohol is the best and easiest to find. and other people agree with me that citrus cleaner is not strong enough. Paint thinner is not good because of the residue so we need to find some acetone or alcohol.
