Best way to attach this?

[Salty]

I'm wondering what may be the best way to attach these corner pieces(in red).
Basically this is a plywood backing that will connect 2 end cabinets. It is about 72" long, 12" wide at the middle section and 24" wide at the ends. I want this to be removable so that the entire desk unit will dismantle. I plan to use some t-nuts that I already have and some flat head bolts to connect the 1/2" plywood back to the corner pieces.
I'm not sure how best to connect the 3/4" corner pieces to the 3/4" plywood. Both corner pieces will be hidden inside the cabinet but I do not want fasteners to show on the outside.
I can do regular biscuits and pocket hole screws. Maybe a combination of both would work, along with glue of course.
Any suggestions?
Thanks.

Salty

[Salty]

Oops

Forgot to add the drawing!

[poolhound]

I'm wondering what may be the best way to attach these corner pieces(in red).
Basically this is a plywood backing that will connect 2 end cabinets. It is about 72" long, 12" wide at the middle section and 24" wide at the ends. I want this to be removable so that the entire desk unit will dismantle. I plan to use some t-nuts that I already have and some flat head bolts to connect the 1/2" plywood back to the corner pieces.
I'm not sure how best to connect the 3/4" corner pieces to the 3/4" plywood. Both corner pieces will be hidden inside the cabinet but I do not want fasteners to show on the outside.
I can do regular biscuits and pocket hole screws. Maybe a combination of both would work, along with glue of course.
Any suggestions?
Thanks.

Salty

Are you saying the red corner brackets have to be removeable or just the back? If they will be permanent and all they are is something to use to attached the back to. I would either glue and biscuit them or even glue and brads should do the trick.

[Salty]

Jon;
The red corner pieces will be attached to the blue 3/4" ply. Considering how well I have seen glue joints hold I suppose I need not get too carried away.
Thanks.

[Pappy]

3/4 square stock to 3/4 Ply, I would glue and reinforce with screws throught the square stock. I use 1 1/4" drywall screws. The glue would be plenty but I wouldn't trust attaching the corner pieces just to a thin layer of veneer.

[LCHIEN]

i would use glue plus either screws or nails.
the trick may be getting enough bite into the plywood if nailing from the inside
You have 1-1/2 inches to work with, a 1-1/4" nail or screw might do the job. If you only have screws a bit shorter than you can precisely countersink the red pieces to get maximum screw into the blue w/o breaking out. Precision countersinking may mean using a drill press on teh red pieces alone.

[messmaker]

Go to the shop and face glue a couple pieces of 2x4. Let it dry overnight. Take a hammer and try to beat it apart. You will have your answer.

[cabinetman]

If you glue and clamp the square stock to the end panel that should suffice. Depending on which way the desk will be positioned in the room (against the wall, or out in the open), I would arrange which side the "T" nut is on and which side the machine screw is on to allow easy assembly/disassembly.

Or, another option is to use bed bolts like these where the nut (cylinder) could be mounted in the back panel, and that would eliminate something showing from one side.
.

[Salty]

Thanks to all for the help.

I set the 2 end units face down with the 30" spacing between and placed the 2'x6' plywood on the back to get a better view of the situation.
After a few minutes it occured to me that I would be better off putting braces all the way across the back of the cabinets. I did this on a vanity to tie the top/back of the side panels. I was going to do this anyway and realized that if I just make them wider I can use that for the t-nuts. I got it all drawn out and I'll take a picture of it later when it is cut out.
For the one near the bottom, I can also dado a slot to receive the bottom shelf.
Since I got a 6" dado blade this operation has become a pleasure instead of a miserable failure.

Salty