So I am I right in thinking that there are TWO separate things to watch out for with grates: Fines build up in the space under the grate, AND fines clog some of the holes IN the grate?
I will be taking care of the stoker/boiler alright, since I am going to be building it
I have seen some stokers burning so I have some idea of what the flame is supposed to look like, and my weatherizing efforts will be finished in the whole house this year so I think I will need only a small fire.. I am planning on reducing the airflow so I get burning over the whole length of the grate, while at the same time not dumping unburned coal.. maybe I can measure ash temperature as it drops off the grate, use that info as a warning or as a control mechanism..
Thanks everyone for all the information.