I used one with out the sides[open on the sides] to temper it, seems to work better and not scorch by going around it as much, all it needed at that point was tempering and no tweaking from tip to tip or propeller twist so I had no need for the regular one. I had been thinking about doing them that way for a while if all they needed was reflex or heat treating. Seemed to work better for me, I tend to put a lot of heat on them and have to be careful not to scorch the sides and back.
This worked out much better.
Pappy