: I have found that a cupped wire brush on a drill motor works great for the
: fast bulk removal before using dragon skin or the drywall sanding mesh for
: final shaping. More than one way to skin a cat or carve a seat.

I'm still using a right angle grinder with a 30 grit sanding disk. You do need to be careful on how you hold the grinder and move the disk in such a way that you are always moving it against the direction it is spinning.

I've taken to putting double sticky carpet tape on the back of the seat I'm making and sticking it to the outside of my house, up about chest high. This holds the seat quite securely and is easy to access.