The Fein Multimaster has spawned a whole new tool category sometimes called Oscillating Multi Tools. Since the expiration of patents a few years back other tool companies have produced their version of an oscillating tool. The movement of the blade or accessory is a rapid back and forth motion of a few degrees. This is a very short movement but the tool is going back and forth as much as 350 times per second. A lot is happening in a short span of time and in a small area.
Most power tools will either pull the chips out of the hole or throw the chips out of the cut. This takes heat away heat and makes room for the tool to drill or cut some more. The short rapid oscillating action just buries the chips in the cut. You smell it first, then you see the smoke curl up just like it's coming out of a chimney. At this point I want you to think of two things; a chainsaw and an iron. With an iron you know it's hot so you keep it moving and with a chainsaw you have a tendency to rock it to help clear away the chips.
Whether you are cutting, sanding or scraping, you need to keep the tool moving so that heat will not build up. If it is a long cut, move the tool back and forth along the entire cut line and spread out the heat. An oscillating too does not jump around with you so you only need to apply moderate pressure to make the tool cut. As you come across the cut you want to tilt the blade a little so you can see the sawdust come out of the cut. The same applies as you cut down through a board you want to rock the blade a little and help it clear the chips or sawdust. A plunge cut will require a little more rocking action as well as some moving in and out. The clearing of the chips will help you cut faster and make the blade last longer. Heat is the issue no matter whether you're cutting wood or metal. sometimes you can even apply a little beeswax, a bar of soap, or just any type of blade lubricant. Anything that reduces the heat build up will increase the blade life. Even as you encounter a nail if you will back of just a second and let the blade breath and then try to spread the heat across all of the teeth this will greatly increase the life of the blade.
Once we realize that this oscillating action is different from our other tools and requres a little different technique then we can work in those tight spots quickly, safely and have a blade that is good for another day.
As the oscillating action is different from other tools so are the blade choices. That's a subject for another day.