If the tree stump you speak of is not still in the ground or,cannot be dug in and secured with concrete or tightly packed soil i would strongly reccomend attatching a platform to your stump to stand on for two reasons 1. your body will help anchor your vise for hammering. 2.if you are standing on the platform the vise is attatched to you cannot move it during bending or twisting operations. Hope this helps