NOTE: All my comments below about straight blades are about a blade mounted on the rear of a tractor. I have no experience with a front mounted blade like you show in the picture.
A box blade is much heavier than a straight blade, my 4' Howse BB weighs in at 400 pounds while my 6' straight tilting blade is 263 pounds, quite a difference. From the looks of your blade it probably weighs 200 pounds or so.
>I have very hard clay soil and my blade will not get into it.
I had a blade that I bolted 2 V8 engine heads to for added weight. I was using it to keep a road graded and the extra weight made a huge difference. Bolted them no the backside of the blade with allthread rod.
The angle of the blade makes a big difference. The more tilt (top away from the tractor, bottom nearer the tractor on a rear mounted blade, in your case the top would be nearer the tractor) you have the deeper it will dig. Takes some experimenting to get it where you want it.
>1. Will I be able to take off layers with a box blade effectively?
Yes, it may only be 1" but a 1" layer 4' wide is a lot of dirt. If the BB is 16" high you would theoretically fill the box in 16' of travel. In reality, you will probably be able to pull 20' or so before the box fills up. You will learn to use the 3PH lift to regulate the depth of cut.
>2. How wide of a box blade can the deere 2210 with turfs pull? I'm thinking only 4 foot because I want to dig with it.
I have pulled a 4' box blade with a Ford 8N (26 HP gas engine), a Kubota
B7100 (16HP diesel), and now a Kubota
B7510 (21HP diesel) and it worked OK with all of the above tractors. With your 23 HP diesel you should be fine.
>3 Can a box blade be put on so the teeth face back and use it in reverse?
I have never tried that but it would put a horrible amount of stress on the 3PH linkage. Personally, I would never try it.
You can use the box blade in reverse to push dirt with but it is much less effective than pulling.
The rippers on a box blade usually have 3 positions, up out of the way, part way down, and all the way down. I have a similar project at the corner of my garage and have used the box blade to move more dirt than you will have to move. I keep the teeth at the mid position. At that position they are about 1" below the bottom of the box blade. Depending on the angle I set the BB at they can dig 3" or 4" deep (with the BB tilted forward) or I can tilt the BB backward and the teeth are just above the ground. With the BB level the rippers tear up just about the right amount of soil (1") for removing in one pass.
>4. Is this a realistic project for my machine and a box blade?
Sounds like a perfect project for a BB. I have a FEL but use the BB for work like this. The FEL is nice for backdragging (smoothing) the dirt but the BB can do the same job very nicely with a little practice.
>I don't want to buy it then find out I need to rent a tiller or something to loosen up this clay.
I suspect a tiller might just get clay balled up in it if the clay is wet. I doubt it would be very useful in heavy clay. Please note that I am talking about really sticky clay like I have, if yours has a lot of sand mixed in it a tiller might work but I would not bother, the BB will work better.
>5 How far in the soil will the rippers go? I would only need about 3 inches in penetration for it to be real effective for my use.
They should go about 3" into the soil but I doubt that you will need that much. If you are ripping 3" deep the BB will fill up in just a few feet.
I have many hours in with both a straight blade and a box blade. If I could have only one, I would choose the box blade.
My comments are also based on the fact that I am in no hurry. If I wanted it done with a week I would hire a dozer but I enjoy my seat time so I will keep plugging away to my projects. If I got it all done in a month what would I do for a hobby?
Sorry this is so long but you wanted specifics so I have tried to give you as much information as possible.
Bill Tolle