Magnesium Alloy?

[Emma]

So, the one thing I can gripe about this game is. How the heck, are we supposed to get this, if I need this to upgrade the furnace to make these and the ruins aren't open for me to get it.

Did the same thing for the steel bars. Why? How am i supposed to get these if I can't MAKE then yet???

[Sagittarius A*]

Look for aluminum scrap. For steel it's iron scrap.

[Sketch Elder]

Use the Civil Recycler and Aluminum Scrap, as shown on the plans for the Industrial Furnace. The Civil Recycler is also used to get Steel Bars from Iron Scrap.

[SimuLord]

One thing the game rewards without outright pointing it out is a willingness for the player to go a bit out of their way to find things.

In the case of getting an early upgrade to the furnace from Civil to Industrial, it requires you to do two things.

One, as soon as you've made the protective suit, go down into the Valley of Whispers and get some aluminium scrap. You can also get advanced mechanical scrap before you're "supposed" to that way as well.

Two, there are dirt piles on the raised submarine (where you get the algae for Zeke's bit that leads to the Biocrust) that will yield you magnesium if you dig them, and once you've got that, you should have juuuuust enough materials to make two Magnesium Furnace Cores to upgrade the furnace.

From there, it becomes easier to stockpile the materials you'll need for a good two or three story beats down the road.