great to know about the oil, Never knew that could happen, the evaporation. Funny about the needles too. I only replace when it gets bent. I do a lot of hand sewing and use the same needle and when I loose it, I need a new one and of course, the old one was dull, but you never realize how dull till you get a new one out. I'm bad with rotary cutter blades too. put a new one in and the cat knocked it on the floor, and it got a ding. I wasn't going to let that stop me. I kept on using that dinged blade til I couldn't stand it any longer. stubbornness on my part.