Martyn said:Yes, I can see the benefit. Are the rivets water tight? How did you brace them on the inside when you were peening the outside?
I haven't tested them to see if they are watertight but I would be very surprised if they weren't.
As for my methods, well, they are a bit on the crude side.
Essentially I chucked a ball peen hammer in a vise and taped a copper washer to the end of it. The rivet end inside the pot sits in the center of the washer as you pound on it from the outside. This lets the rivet mushroom on both sides.
Once you get it mushroomed fairly well you can flip it around, place the rivet end on the outside on a hard surface, and using a SMALL hammer, flatten the rivet a bit more on the inside.
You need to make sure the material you use for a rivet is nice and soft. I would practice by using a flat piece of metal, drilling a hole in it, and pounding a rivet through the hole. This will also give you a good idea how long to make your rivet to begin with. You can always file the remainder down a bit if you need to after you are finished.