yeah 1/2" inch round over. I need to get a 3/4" but they are expensive. This will be my first attempt at a mirror piano black finish. I will post pics of the final product.
More longer clamps (you will need them). A larger round over bit will get rid of that and give you the desired round over. A need a larger bit myself but they are expensive, so I let the sander take care of it for now.
I have never used the tongue and groove method. I don't even use screws on comp boxes with 50lbs subs in them. (Just my experience, Never had a problem with one coming apart). If you have a router handy, get a good round over bit to round the edges. I also use the router with circle jigg...