just removed one of my 13usg tanks due too failure of the baffle ribs, noticed with full tanks a bulge in the lower skin on both sides, defueled and boro scoped to find bottom skin detached.
new tanks 0n order however laa engineering are checking whether poor build or ethanol related. 1994 denny aircraft grey tanks,
no heavy landing or jolts or leaks, dashed good weather this summer to boot