I want to basically clear all values in an existing raster and then replace them with values from another raster, without writing to a new raster dataset. It seem like basically all functions/tools write things to a new raster dataset. For instance if I want to make all cells in an existing raster dataset to be equal to 100 is there a tool/process without writing to a new raster?
Neal, that is standard practice. If it is a naming issue, follow your combine process with a Delete of the original input and a Rename of the newly created output