that reminds me of the stuff called Rubberize it...
There is a youtube video of someone making a wooden plywood tank with the rubberize it material and looks cost effective and he has a really nice setup.
I wanna try something similar to the guy that made the plywood tank with this material.
Anyone else know of any disadvantages to using this material??
I haven't tried Flexseal but I used the Rubberize It liquid rubber on my 280g ply build. They're product is called Aquaguard Liquid Rubber. Can be used in ponds and potable water containers and can be applied directly to plywood.