Update:
The last of my sieves showed up last night, so I was out this morning doing my final steps. First, I tried some store-bought powder in the seives. My Swiss 3f went through the 40 mesh. my Goex 2F went through 20 mesh and was caught by the 40.
1) I broke up the big pieces into smaller ones using two wooden block, and serving with 4 mesh, and then 10 mesh.
2) I took what fit through 4 and kept crushing until it all fit through 10 mesh.
3) I took the 10 mesh and ran it through a ceramic coffee grinder as course as I could make it.
4) I too the resultant and sifted through 16 mesh and then ran everything that got caught through the grinder again on a slightly finer grind
Throughout this, I sieved each batch through the 20 and then the 40 mesh so I was not regrinding stuff that was already at the proper grain.
When everything I had either passed through the 40 mesh or been caught, I considered myself done.
What went through the 40 mesh is a mix of 3F( give or take) and fines.
When got caught by the 40 mesh is roughly 2F.
I tested both. They gave me a nice "FOOMPH!"
Should I order a 50 mesh sieve to get the fines out, or am I good to go?