Tip: What you can do with your old metal chairs?
My husband used old metal chairs, that had no seats,bolted them together By drilling holes through the metal. Bought cedar that happened to be on sale. He cut & sanded the cedar. Used a polyurethane on the wood for outside use. He used screws to attach seat to frame , screwing from the bottom, making sure they were short enough to to come through the top wood. To do this project this way you would have to be a handyman. Without him I would have used bungee cord to hook them together and added a bench pad. Any way you do it I love repurpose and keeping things out of the dump!
I love it.