Normally use lead tape to increase SW on assembled clubs. Is it feasible to add 1 gram of powder down graphite iron shaft? If so, how would I hold it in place. Not sure if there’s a small enough cork.
One gram isn’t much. You can get away with that. You have to get a small cork and sand it way down. Failing that a little bit of pink insulation would hold it in place. I’ve used insulation before. I would use the tungsten powder. Tungsten is heavier than lead. Safer too.
Convention tells us that a lot of lead down the shaft greatly increases the possibility of a sheer point on the shaft.