Interesting, I understand the concept but I've had a night to sleep on it. I've got 4 x 8 foot 3x3 posts coming to be cut down for the hoover dam bit at the back I could put in the wooden channels for the concrete on both sides and brace them across the hole with the posts. I could the brace them against the bottom of the hole with the posts that are holding up the current bit. Then get some roof battens(very cheap) cut them down to hold the outsides as has been done with the bit that is done.zennzzo;2090655; said:On the places where the forms haven't got a place to be staked down, you can use threaded rod and large flat washers and nuts to hold the form together...this will keep it from bowing...In the concrete business they are called "ties"
After the concrete sets you can cut the rods off or drive them through flush with the inside of the pond...
Just thinking along the lines of not spending when there a solution at hand?