Model IV Fuel Tanks - Is This Normal?

[wgilbrech]

Hi all, I'm a long time lurker who's just getting started on a Model IV build. Y'all's build logs and comments have been incredibly helpful thus far.

Anyways, I was washing out my right fuel tank today when I decided to peek inside. This is what I found:
28350

Is that normal? There aren't any leaks but I'm worried there is serious delamination going on and that I need to toss the tanks. Side note - after washing it out with water, the tank felt warm to the touch and exhausted warm air. Would washing them out cause some sort of reaction?

Regardless, thank you all so much for any help beforehand. This build has been a lot of fun and I'm excited to get it in the air.

Will

[avidflyer]

I have one apart right now, and that's about what they look like. Kind of sloppy looking inside, but they work. Just a baffle you are looking at. JImChuk

[wgilbrech]

Got it, thanks so much!

[sturdee]

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