With mutants becoming more powerful and only having a few weapons in your arsenal, it’s not a bad idea to upgrade them.

With the furnace, you can upgrade your basic weapon to something a bit more lethal.

In this survival guide, we’ll show you how to build the furnace and upgrade your weapons in Sons of the Forest.

To see the process for yourself, be sure to watch the video below!

Where To Find the Furnace Recipe in Sons of the Forest

To find the furnace recipe, you’re going to need to explore the pickaxe cave.

It’s an enemy-free cave, but it does require the use of a Rebreather.

There are also moments where it’s easy to become lost.

Along the way, you’ll pick up the recipe for the furnace as well as pickaxe.

Use the pickaxe to mine some solafite ore while you’re there since you’ll need it to upgrade weapons later.

How To Build the Furnace in Sons of the Forest

The furnace is the crafting station in which you’ll upgrade your weapon.

You’ll find it in your building menu in a new Note section at the bottom.

Find the recipe, then select it to build.

Place the blueprint where you want, and then start collecting your resources.

As a side tip, I’d suggest building the furnace somewhere out in the open.

It shoots out lasers which can destroy a roof.

You’ll need the following resources to build the furnace:

• 3 Wire
• 11 Sticks
• 4 Golf Cart Batteries
• 3 Turtle Shells
• 7 Stones

Feed each resource into the blueprint until it’s finished.

Your furnace is now ready for upgrades.

How To Upgrade Your Weapons in Sons of the Forest

You’ll need six solafite ore to put into the furnace to upgrade a weapon.

Once the furnace is full of the ore, you can select a weapon to upgrade.

Keep in mind that not every weapon is upgradeable.

A wooden bow, for example, isn’t capable of upgrading.

Equip the weapon you want to upgrade, then interact with the furnace.

Once it’s in place, press the power button on the batteries.

It should spark to life, sending off lasers everywhere.

Now comes the hard part.

While your weapon is upgrading, your base is going to be under siege from mutants.

Even the weather changes to a thunderstorm.

For the next few minutes, you’ll face wave after wave of mutants.

Depending on how far you’ve progressed in the game, you might face some dangerous mutants.

It’s worth building the furnace far from your base to prevent mutants from breaking into it.

You can also build the furnace in an area that you can use as a kill box.

Once the weapon has finished upgrading, the waves of mutants will stop.

You’ll be able to take your weapon out which should look different and have different stats.

You can start the process over or prepare for your next upgrade battle.