All the naysayers who said there would be epic failure were right. The screens collapsed in on themselves once the water level dropped. It probably wouldn’t have happened on a fly sparge or if I doubled up the screens but I just said to hell with it. With the right tubing being under $20 for the kit I would need to remake all my crap, I just bought the correct stuff. While it turned out to be about 3/8ths inch rather than the one half my connectors all are, it semed to turn out OK. I may want to revise it one more time to actually put a pipe on the floor of the tun to get some siphoning action, but it sounds like too much work and I could also simply tilt the grainbed a few degrees and make up for it.
Anyway, here’s the mash tun, rev 3: