It takes a lot of energy to produce aluminum. Reinforced paper mache will work as a good substitute.
You bet energy intensive. The further you move to the left on the periodic chart the more power you need to make the pure metals from ore. Aluminum is a very interesting material. It readily reacts with air, but the reaction is so efficient that it forms an aluminum oxide crust on the surface, protecting the rest of the metal and making it corrosion resistant. Light weight is its big benefit.
The British lost an aluminum ship during the Falklands war when an Exocet missile from the Argentininas created enough heat to melt that crust. Metal was exposed and oxidation took off generating enough heat to keep the process going.Was a very nice efficient ship until there was a war