Do you have any St Augustine right now? If so then this is not a project at all. It is a matter of mowing and watering...properly. St Aug will take over just about anywhere that it will grow.

My next suggestion depends on the answer to that question.

Sand is not a problem for St Aug. It is native to coastal South Africa. I've never read anything about sticking the soil together - at least not in this context.

Dave, I'm not really sure about using a sod cutter, but moistening the lawn is often suggested to make mechanical routines easier. Moist soil will give easier than hard, dry soil. You might want to call and ask a local landscaper to be certain. I don't doubt it though.

If you do moisten it, keep in mind moist doesn't mean wet. You don't want to have to create a sloppy mess. You just want the labor of the job to go easier on your back. LOL

David knows way more about St. Augustine soil requirement than I do, so I'm not disputing him. I am just most accustomed to sandy soil being unable to retain moisture. I'm thinking that since you are cutting away the sod anyway, it might be a good time to correct the soil composition. The following links might be helpful.

Information here to help explain soil composition.
Information here to explain grading zones.
Information here on using a sod cutter

I strongly suggest you not make the area moist, damp, wet etc. The only reason I can think of to moisten the area is to keep the soil intact with the sod, as if you intended to sell or transplant the sod. Remember you have to remove all of this from the site. The last thing you want is to haul HEAVY moist sod, weeds and soil.

Last year I took on the same project as you. Click on my user name for detailed info/pics. In the first pic you can see the sandy soil literally falling from the cut sod.

Oh, I see why you need to make the soil sticky. If you cut sod out of sand, the sand will fall off the roots. Aha! The light bulb is on now (maybe dim, but glowing anyway). Okay but why would you want to cut the existing sod out? That is like trying to save the gaskets on your old carburetor when you take it apart (sorry, I flashed back to my youth there for a second). Meticulously cutting out the sod is a huge (HUGE) waste of time.

I am a firm believe that almost every situation can be turned around without a major overhaul. I still need to know if zyrtecdave has any St Augustine now. If so, it can be brought back to become the dominant species without much trouble. All you need is one living sprig to start with.