The "Sponge" and the baffles in a 5 HP Briggs Gas Tank

[Seakaye12]

Why are they in there? The baffles I suppose are there just to minimize agitation from vibration etc....but WHY the "sponge"?

Also....while we're at it....what method do you guys like the best for removal of rust in a tank like this? Vinegar, Muriatic acid, something else?

[Luffydog]

I use a small chain when I can and shake the h3!! Out of it multi times until clean. For the sponge its to help prevent air pockets.