Got hold of another 5 gallon beverage cooler so I could have two mashes going at once. Since the manifold in the first one has served me well I didn't see the need to change the design. I did however sweat the first one together and was not going to do that. I throw out the idea of using stainless sheet metal screws to hold it together while still allow it to be broken down if need be, so that's what I did.
Why use anything to hold it together. I use a copper manifold for my AG batches and have never had a problem with it coming apart. I just press them together and set them in the mash tun. Unless your smacking it on purpose with your mash paddle it should be fine, plus its extremly easy to clean. I just take mine apart and throw it in the dishwasher when I'm done.
No doubt you can design the manifold so there is little room to move and get away without the need to have anything holding it together. I just thought of using screws to hold it together a couple months ago and put it into practice. Haven't come across anyone else doing it so just throwing it out there.