For give my ignorance. I am sitting here pondering if I should purchase a 60in Scrape Blade or a middle buster to place small trenches next to my roads and probably a few other places. Or should I use the box blade that I already have. The sales me told me I can do anything the scrape blade can do with the box blade but I would like to know what you think. Thanks in advance-Bill
I have both, and do exactly what you're asking about, so I feel somewhat qualified to comment. Other's have done this a lot more than me, so don't take it as gospel.
For cutting a ditch, a rear blade is the bees knees. Put a big angle and tilt on it, go slow, and it'll pull a nice (6" to 1' deep for me) in a single pass and deposit the scarf up on your road/trail. A BB is near worthless for this, I can't get enough angle, and, even when I can get it to start digging, it wants to jump out of the ditch the first high point I hit.
Now, if you're following, you've got a trail with a big berm of dirt from where you cut the ditch. Here's where the BB shines. Hook that up and I'll distribute that berm all over the trail nice and even, and put a great surface down to walk on if you tilt it way back to rest it on the rear blade (not cutting, just compacting). For me, it's a 2 step process, use a rear blade to dig the ditch, and the BB to level out the scarf and make the road/trail surface. You could do it all with the rear blade, but it's a lot more work to get a nice level surface (at least without gauge wheels, which I don't have). I use a 84" rear blade and 72" box blade on my tractor, the rear blade being bigger is important so you can cut the ditch without being in the ditch.