default value for SUM

I have a sql query that sums a database column. When the data in the column in '0' it prints out to my datagrid nothing, blank.

Is there a way in the SQL statment to somehow assign a default '0' value so that it prints out to my datagrid. Here is the SUM part of my sql code

SUM(nonconformance.nc_wafer_qty) as 'wafers'

ISNULL(SUM(nonconformance.nc_wafer_qty),0) as wafers

|||thanks doug.