We had club project at my house and guess what we did?
My poor patio furniture had lost all it's luster so we spray painted them and made them better than new!
What a difference a few cans of spray paint can make!
I pressure washed them to see if I could just wash off that grey oxidation but nope, it just made it worse.
So I headed over to Home Depot and picked up this:
Rust-oleum Hammered - Dark Bronze.
It's a miracle worker - I swear to you!

