Usually burn coal in winter in this stove. Wood in shoulder seasons. Have LOTS of wood ready to go. Thinking of going with just wood, as oil is low and can use it when not home, and get rid of some excess wood. Only problem is the grate system in the Harman does not do well with coals. Question is how thick a piece of sheet steel would I need to place on top of the grate system? And would this work to avoid the coals going right into the ash can? Anyone have any ideas?