My daughter loves to buy other people's junk and have me refurbish it. She bought an old floor lamp that I've restored except the base. It's made out of metal, and whatever cement-like material was in it has disintegrated. A picture of the empty base is below. I'd like to fill it with something to add some weight and to shield the sharp edges from my granddaughter. My first thought was epoxy, but that's too expensive, and I've never done it before. My next thought was cement, which I've done once or twice 100 years ago. Would the cement adhere to the metal? Is there another readily available material available locally that I could use to fill this base? It's 10" diameter.