Curiosity got the better of me last night and I removed the resonator from my dobro. It was quite an educational experience.
I learned that nearly all the weight of my instrument is due to the heavy wood construction of the body. The resonator cone and spider are extremely lightweight. The cone isn’t much heavier than an aluminum pie pan. I also learned that no matter how much I vacuum out the resonator, I’ll never get the cone as clean as I can with soap and water. Unlike with a guitar, there are lots of nooks and crannies for dirt and randomly dropped items to collect inside a resonator. I did a thorough cleaning before I put it all back together.
It’s pretty cool to see what’s inside but I don’t think it’s meant to be opened up regularly. The resonator cover is held in place by 12 wood screws that screw straight into the laminate top. It seems it would be easy to strip out a screw if they were removed too often. Fortunately, I got everything back together without breaking anything or causing any rattles to develop, and now my curiosity is satisfied.