Edward,

The problem I have seen with refractory is, if you count on the stiffening to reduce the SIF on a fitting for instance then the real world will make sure it cracks and does'nt stiffen the damned fitting.

On the other hand if you ignore it it will sure as heck overload something because of the added stiffness.

I guess I would say I don't like it because of its inconsistent nature, then on the other hand my family accuses me of the same problem