My alliance is hooped because no iron?!

Hi, I recently joined this alliance and it's pretty active and everyone is great. But there are a lot of new players and the previous leaders dropped the ball on some things and they have wasted alot of banners. So we are stuck in the edge of the plains and need just one banner to capture an alliance iron mine.

Problem, we only have 3k iron and 6.8k. it is like a catch 22. I am trying to research anything with iron contributions in alliance tech but nothing really contributes iron. So how do we get iron if we need iron to get iron. I have a little experience in the game, but never had issues with banners.

Oh, and are alliance of 88 is being blocked by a tiny alliance of like 5 players because we can't build this one banner. We are on day 22 so no alliance resource exchange either.