Hi folks, I need to plaster over a steel lintel over an open fore recess. Its visible surface is 6" x 31" . It is 1/4" thick steel. The steel will get fairly hot (I guess about the pemperature of boiling water but not much more) because it is in close proximity to a fire. That means the steel may expand and contract somewhat. I'll be using one-coat plaster from B&Q, and the plaster will be about 6mm thick over the steel. What is the best way to ensure the plaster stays stuck to the steel? One idea I had is to rivet a piece of perforated sheet-metal to the steel before applying the plaster. Any other suggestions would be appreciated.
Thanks
Frank Z