lazlototh - Posted - 07/25/2025:  17:59:49

I recently fitted a 1929 TB2 with a Corian ring. The original tubular ring really did not weigh much but the owner liked the conversion I did on his Deering Sierra, so we did this one. The Sierra lost about 2.5# in the changeover.

I did not modify anything on either of those instruments, so they can easily be converted back to original. The Corian is quite machinable.

The Gibson has a block rim and the sound really impressed me. That was enough to look at making a block rim.
Not having a lathe and not being tied to doing things in a normal way, I made an 18 block rim with only one layer of blocks. The tension hoop I am using is a drum hoop. It only has six fasteners. I tapped round shoes to accept my top tension bolts. That works fine and I can easily tension to 90.
Of course, as you block builders know, block rims are made of layers to get more strength. I had two glue joint pop apart under tension. They were not completely glued. And my angles were slightly off.
The second one I did is this one. It is 3/4" thick walnut with a 1/2" tall Corian tone ring. The dowels are permanent, so I can simply lag to the wood rim. That seems to work fine.

The next one, which is oak, will have a bottom cap of 1/4" to overlap the joints for extra strength. And I am much more careful about angles and gluing.
It is almost too loud without using a resonator. It weighs 4# 14 oz. Resonator would be another pound.

martyjoe - Posted - 07/26/2025:  00:24:33

Nice one. I recently bought two drum hoops (10”&12”) with six holes to use in the next couple of builds. I’m keen to try the five hole version as well. The five hole should work well for me because I always offset the neck from the center line of the pot. I’m working with Hannex which is the Hyundai equivalent of Corian. My plan for the Hannex is to mainly use it in harp frames but I also put it into some of my banjos. 

Edited by - martyjoe on 07/26/2025 00:29:53

lazlototh - Posted - 07/26/2025:  01:28:16

Hi Marty,
There are several of those Corian style options that I would like to try. Finding Corian is a bit of a challenge. It is readily available if you purchase a rather expensive full sheet. Partial sheets can still be pricey. Fortunately, the amount needed for a good sounding banjo (even with a Corian resonator) is not great.
I also have found some of the older products is not very thermoformable for banjos. It breaks into pieces.
Newer material seems to work well, although I recently snapped a hot ring in half.

I tried the 5 hole hoop. It was thinner than the six hole and deflected too much.
Looking forward to your adventure.
Make sure you have some insulated winter gloves that do not melt.