Old-Fashioned Method to Harden the Ice Cream...
Leave ice cream in the canister.
Place a sheet of waxed paper across the top of the can; place the canister cover over the waxed paper.
Drain water and repack freezer with 5 parts of ice and 1 part of salt. Do this until entire canister and lid are covered with the ice and salt mixture.
Cover with a burlap bag or some suitable materials for insulation. Let stand until frozen hard. Oftentimes 30 minutes are enough, but you can easily check by removing the canister lid and testing the hardness of the ice cream with a spoon.