Bearing Cleaning and Lubrication
There are many ways to clean and lubricate your bearings. Online, you'll commonly see methods such as using citrus cleaner, acetone, isopropyl alcohol, and even gasoline to clean out dirt, oil, and debris.
Which method is correct? Well, the answer is that it depends. Different methods have different advantages and disadvantages to them.
Two methods I enjoy using are ones I'd never recommend to someone inexperienced due to the use of water.
Keeping water away from your bearings is one of the most important things when it comes to preserving their longevity. You must take all measures possible to avoid rust, especially on the inner races of the bearing. Once it forms, it is incredibly difficult to get rid of, and we all know how rust eats metal. Therefore, most recommended methods of bearing cleaning do not involve water-based cleaning products.
However, I have found that it is possible to clean bearings with methods involving water, and that there are certain advantages to it.
The first method involves using cavitation. This is most easily achieved via the use of an inexpensive ultrasonic jewelry cleaner. Surprisingly, it works well to clean bearings, and its effectiveness is further increased when submerged in isopropyl alcohol. I don't recommend using isopropyl alcohol with the ultrasonic jewelry cleaner because of the explosion/fire risk, but have done it many times. This method of cleaning bearings tends to work best on bearings that were NOT lubricated/packed with grease. It works well on bearings that are not incredibly dirty, and is best for preventative and routine cleaning.
The second water based cleaning method is by diluting a concentrated automotive/kitchen degreaser in water, then submerging the bearings with the cleaning solution in a sealed container and shaking. Repeating as necessary. Much like how you would clean using any other standard method like citrus cleaner, isopropyl alcohol, acetone, gasoline, etc.
This method produces similar results to those other more common ways of cleaning, but it tends to be much cheaper, and isn't a fire hazard. The fumes and toxins are not nearly as bad as other methods, save for using citrus cleaner. It works very well on bearings that are greasy, since it's specifically a degreasing product.
With both of these methods, I first use water to get rid of easy-to-remove debris. Both spraying water from a sink or hose directly into the bearings, and also shaking them around in a container just like you would with the cleaning product. This is great because you can flush out a lot of the debris just by using water, before running the ultrasonic cleaner or using the diluted degreaser.
After cleaning, you will rinse again with water to ensure that all of the degreaser is washed out of the bearings, you don't want any excess residue left inside them. Side note: that residue is one issue with using citrus cleaner.
The most important part of the cleaning process when you are using a water-based method, is drying. You must ensure that the bearings are completely dry before adding lubricant, or rust will form and ruin the bearings. There are multiple ways to do this.
My method is to throw all of the bearings on a towel, wrap them up, and shake them around until most of the water has been absorbed. Then, once you make sure the bearings aren't dripping wet, you need to pick how you're drying them out before rust forms.
Laying all the bearings on a towel, you can use a hair dryer on the highest setting, and continuously pass over the bearings, starting with the internal side facing up, which is where most of the water will be pooled. Then you will flip the bearings around shield side up, and do the same. This should be repeated for a few minutes, and the bearings should become very hot to the touch and unsafe to pick up. The goal is to evaporate any residual moisture left inside the bearings.
Another way is to throw them in the oven for a few minutes at a medium heat. Just be careful that you don't forget them in the oven, and don't go overboard on the heat either. Somewhere between 200-250 degrees fahrenheit for about 5-10 minutes has worked for me. Bearings usually contain plastic/nylon cages which can warp if exposed to excessive heat. These can also be damaged over time if you are cleaning with harsh substances such as gasoline.
Once you are confident the bearings are completely dry, then you can lubricate them. One tip, don't immediately seal them in any airtight containers. Sealing them in a container will cause even more rust to appear if you made a mistake and didn't dry them out enough, compared to leaving them out overnight before storing them.
-
Other methods of cleaning bearings as I mentioned before, such as using citrus cleaner, acetone, isopropyl alcohol, and gasoline, all pretty much follow the same formula. Submerge the bearings into the product and shake, drain and repeat until clean. These products work well overall, but disposing of them correctly and handling them safely can be challenging. Isopropyl alcohol is my favorite, and it is technically a method that involves water too.
You can buy different concentrations or isopropyl alcohol, 91% is the highest concentration you can easily find, but I dislike it because it still has some water content. 99% is the best type to use for cleaning bearings. It can be more difficult to find but it's worth it if you don't want to spend time using the hairdryer.
Citrus cleaner is also a good option, but as I mentioned before it can tend to leave a film or residue in your bearings. Both isopropyl alcohol and citrus cleaner work best with oil-lubricated bearings, and bearings that are not filthy. Similar to the cavitation method, they are great for routine cleaning.
Acetone and gasoline work great at degreasing and getting your filthy bearings completely clean, but they are also the most dangerous methods of cleaning. You must also be careful not to leave them submerged for too long, or the plastic cages can be degraded. Disposing of these can also be an issue.
The frequency of cleaning should depend on how dirty your skating surface is. However, sometimes even if your bearings aren't dirty, they will need lubrication before they need cleaning, and you'll need to clean them anyway before lubricating them again. This is especially common when you use oil instead of grease, the oil will leak out long before the grease needs to be replaced.
There are also many ways to lubricate your bearings. I personally recommend a light machine oil, like 3 in 1, sewing machine oil, or my personal favorite, turbine oil. Oil works well to give your bearings lubrication without slowing down their roll, but requires cleaning and re-lubrication more often due to it leaking out. With the light machine oil, less is more. Just a drop or two is sufficient. If you add too much, oil will leak everywhere and attract debris.
Grease is another option for lubrication. The advantage of using grease is that it will stay inside your bearings forever, and is what I would always recommend to anyone skating outdoors. Grease is superior to oil when it comes to protecting the internals of your bearing. One performance issue with grease is that it can increase rolling resistance and make you feel a little bit slower until it warms up, especially if you've packed the bearing with grease. A good compromise if you are doing indoor skating or a mix of both outdoor and indoor is using white lithium grease. You can get an aerosol spray can of this stuff at any automotive store, and it tends to be much lighter than other greases. Using just a little bit, it can be very comparable to oil, and theoretically should last longer inside your bearing. Grease also tends to do better in bearings that are already in very rough shape, and if I am attempting to salvage a damaged or vintage bearing I will always use grease.
My personal issue with grease is that it is incredibly difficult to remove from the bearings compared to oil. When your bearings eventually do need to be cleaned, I find that bearings lubricated with grease need the harsher chemicals or degreaser to be used, otherwise there will be some residual grease left inside the bearings. This is a particular problem not only in removing all the debris stuck in the grease, but also when you want to change your lubrication method to oil. If you can't remove all the grease inside the bearing, you should continue using that same grease (just add more) for lubrication, otherwise if you start to mix lubricants like oil and grease, you can create a sludge that does you no good.
For competitive skaters that should be cleaning their bearings relatively often compared to recreational skaters, I would always use the light machine oil. If you were to use grease, I'd stick with the white lithium.