Oil daily or void the warranty on this $20 grinder? How about flushing the new tool out with denatured alcohol and never oiling it again?
How many times have you picked up a die grinder or drill and oiled it before working on your composite aircraft? You likely oil daily because you were told to do it. Yes, it lubricates, but “oil daily” really refers to oiling at the end of the day so the tool is coated and protected from internal rust as it sits in your toolbox between uses.
Usually, what goes in must come out. The exhaust port of your tool is spewing that oil and depositing it all over your composite structures. Oil and bonding do not go well together.
If you flush it and run it dry, yes, it will get noisy. Sometimes it will require a flick of the finger to get it rotating, and eventually, it will seize up and call out for the trash can. Expect a couple of years if you use it frequently, less if it is an occasional-use tool. Using it frequently will actually help keep the bearing surfaces free of surface rust, whereas occasional use will allow that rust to cause failure faster.
If your expensive air drill is oiled before, during, and after each use—great! It will last many, many years. However, consider buying a cheap drill for operations that do not require the closest tolerance holes. Then, use the expensive, oiled tool with a small rag wrapped around its exhaust port only when necessary.
For those inline and 90° die grinders, rinse them out and use them until they die, then do it again … it is cheap insurance and good practice when a secondary bond relies on being clean.
