What are the properties of Mobile 1 that make it work better? Any ideas?
The only thing different about it is, it's a synthetic oil, our theory is that once you start sanding, it traps the grit that would normally fall off the blade, or collect at one end or the other. Which is why it is important to clean the oil off the blade when you change grits, if you go from say 180 to 220, it might still look OK, but the finish will have larger scratches with the smaller ones, which I think would not look good on close inspection.
Do keep in mind that it doesn't take a lot, I have a real small plastic cup that I fill about an 1/8th inch from the bottom, I use one of those small 1" sponge paint brushes to apply it , the sponge collects it and holds it, that way there isn't enough to spill when you knock it over. My first quart lasted a year, and I wasted a lot, either by using too much when I first started using it, or by spilling it, a very cheap highly effective method for getting a fine finish! I have thanked Frank for sharing that tip many times, and I still feel like I haven't shown enough gratitude, it saves so much time and gives such a wonderful finish!
I think the sandpaper matters a lot too, crappy paper will only make you use a lot of it, and work twice as hard. If you've never used Rhinowet Redline, it is awesome, I'm very frugal with it, you don't want to continue using the same grit it if it isn't cutting, like all sandpaper, I cut mine into 1 1/2 to 2" strips and wrap it around a bar of steel I attached a 9oz strip of leather, I used 2 sided tape, it's easy to remove and clean up and has lasted over a year, the bar is about 2 feet long, it helps a lot, and gives you some leverage on the paper. I got that tip from Stephen Fowler, ya got to be careful with your grindlines doing it this way, it will wash them out in a heartbeat, when you need a hardback I just flip it over and use the bare steel side. Rex