The radiator edger is worth it!
If you've got one of those lovely Twin Cities houses with cast iron radiators, how do you sand around it? Great question - we're glad you're proactive about solving potential sanding challenges.
A little background: when you sand your hardwood floor, you use (at least) two machines: a drum sander and an edger. You'll use the drum sander on the main part of the floor, but the edger will allow you to get close to the wall and into corners.
In this case, there is actually a specific radiator edger you can use. You'll do a better job if you use the radiator edger to sand underneath the cast iron radiator after you've used the regular edger up to the face of the radiator edge. The same is true if you use the radiator edger to sand under the toe-kick of your kitchen cabinets. Do it last, after you have done all the grits with the regular edger.
Here's why: the radiator will provide a distinct, finite face against which to sand. However, that can leave a very distinct sanding line on the floor, just under the lead edger of the radiator. If you use the radiator edger after you've left that line, you will sand over and feather that edge, which will blend and feather it and make it much less noticeable. Voila!
So, to recap for cast iron radiator owners:
1. Sand with the regular edgar first, up to the edge of the radiator (or up the the face of your cabinet, if you are doing a kitchen).
2. Switch to the radiator edger to blend the sanding line in.