SWIM just tried it and is pretty frustrated with one step.
Everything went perfectly fine, freebasing, pulling with acetone, salting out with fumeric acid....
Then when the acetone was filtered what looked like a decent amount of brown-sugar colored clump was collected in a coffee filter.
The coffee filter was soaked in ~40-50ml of water and turned about the same color of the acetone, all of the filtrate seemed dissolved.
SWIM added sodium carbonate pinch by pinch, at least 3g was added in total and completely dissolved and.... nothing.
SWIM saw the tiniest specs of brown floating around, but maybe 3-4mg maximum compared to SWIM would guess >200mg of the filtrate.
SWIM tried putting the solution in the fridge... no change....
HELP?