greengiant;2462712; said:
I love the look of the exposed 2x4s as well...
I'll also vote for really liking the look of the exposed 2x4's.
But I'll disagree slightly with some of the previous replies about the exterior skin not adding any strength. With plywood skins on the outside, glued and screwed, you'll be creating a type of stressed-skin structure which are very strong. This type of structure relies on skins on both sides, not just one.
Now whether you need it or not is another question. I'm not sure if I completely understand the exact construction method used.
If it's just 2x4's edge-glued and screwed I'd have some concerns. With the vertical orientation of lumber the grain of the wood won't offer much strength.
Think of a martial arts demonstration where boards are broken. The boards are always broken across the face grain, with the grain running parallel with the edge of the hand. If the board were rotated 90* it would be much harder to break. And if it were a quartersawn or edge grain board it would be ever harder to break.
But like I said I'm not completely sure about this tank was constructed.