The overall question is how to calculate the current carrying capacity 
of a thermal relief.

     IPC - D-275  indicates that the total area of the thermal ties should 
be used to calculate the current.
     However, the  chart on page 10, to calculate current capacity of a line 
makes a assumption that this is
     a long free line.

     Since the thermal ties are very short (.010) and tied to a plane.  This 
adds a lot of heat-sink and it looks to me like this
     needs to be taken into account when calculating current capacity.

     Any experience out there with this problem?

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