The second thing you'll need is something made of copper.
The object itself doesn't matter, just as long as it's made of copper.
It could even be something random, like a cooking utensil. Wink, wink.
Item locations have been pretty devoid of logic thus far, but the cooking utensil is exactly where you'd expect it to be.
Visit the kitchen - you'll find a copper ladle next to a big pot.
If the kitchen's locked off, follow these hints.
Next up - something made of zinc.