I’ve been making some adjustments to the “Industrial” oil can banjo. It was bothering me that the volume on this banjo was lower than I wanted or expected. There are several factors that could affect the sound from the construction and weight of the can itself to the bridge to the nut, or the strings. 
The first thing I tried was changing the bridge. I used a piece of cedar as suggested by Dena at Story Gourd Workshops and made a super-lightweight two-post bridge. This resulted in a huge difference in the volume, night and day better. I also replaced the original ebony nut with one made from bone. I don’t believe this changed the volume very much but it did result in a richer sound. Part of the problem with original nut was that the slots were two broad. I bought a couple specialty slot files from Stew-Mac and was able to make slots in the new nut and bridge that fit snugly around the strings.
Finally, I wanted a strap for this instrument and I made one from an old neck tie and a D-ring. I fastened the D-ring to the bottom of the can with a self-tapping screw (I didn’t want to put pressure on the tailpiece) and tied the other end around the peg-head. Simple, strong and looks really good too.
I’ve been playing this instrument much of the evening (learning Cold Frosty Morning) and I love the sound I’m getting now. As soon as I have this tune down a little better, I’ll make a little video so you can hear the new improved sound (in spite of my playing).