My horn is a Getzen 3047AF, but I suspect this will work for most trombones. I have been using an Edwards counterweight (4 3/4oz) that wasn't exactly balancing the horn (heavy handslide). I had two different 3-piece King counterweights laying around that I've always admired the look of so I did a test fit. (Side comment: I didn't realize the 3-piece counterweights came in different sizes: mine are 5 5/8oz and 6 1/4oz). Both were designed for a thicker King tuning slide brace.

First thought was to wrap the brace with tape, but that would be too messy. A paper wrap would fall apart at some point. I ended up using aluminum foil: take a small sheet (~8" long) and fold it so it will be covered up by the width of the counterweight; wrap the foil around the brace (doesn't have to be tightly wrapped) so it's thick enough so the counterweight slides over it snugly; add the other two pieces of the counterweight and tighten. The foil conforms to the surface of the brace and it fills the voids between the bore of the counterweight and the brace.

I used the 6 1/4oz weight and my horn is now better balanced. The interface between the counterweight and the brace is metal so I'm thinking there's no 'deadening' affect of, say, a silicone tape or paper wrap.

<YOUTUBE id="f4OTj9yNOak">https://www.youtube.com/watch?v=f4OTj9yNOak</YOUTUBE>