Mix two parts lye and one part water. Boil this lye mixture in a metal pot on the stove. Add 1 cup of zinc oxide to the mixture. Allow the mixture to boil for about 10 minutes.
Pour the mixture over the hot-rolled steel bars. The rusted particles on the steel should try to bond with the positive charge in the liquid, removing it from the surface of the steel. Repeat this process until all rust is removed.
Clean the surface of the steel bars with a soft cloth to remove any leftover residue.
Inspect the materials surrounding the hot-rolled steel. This material could be wood, cement, foam or other materials. Choose the appropriate tool based on the surrounding material. Use a jackhammer for masonry, a jigsaw for foam or wood and a chisel for smaller pieces of materials.
Remove any screws or fasteners holding the steel pieces in place using a screwdriver or ratchet.
Wear safety equipment while removing the exterior materials. Chip away slowly at the material so you do not touch the metal itself. When the steel is loose enough to pull out, pull it away from the exterior material.
Chip off any remaining materials with a chisel. Sand the surface smooth with a belt sander.