--Lampblack. Hold the threaded rod in the smoky part of a candle
flame; works fine for making telescope bearings at least..
--A possible plan B would be to cast the bob from buckshot, held
in a resin matrix. We used to pour keels for model sailboats this way,
using a fiberglas shell to get the shape we wanted.

--
"Steamboat Ed" Haas : Somehow related
Hacking the Trailing Edge! : to Lumpy Adams...
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---