Hey Rula, you're right, 42 µm and 73 µm isn't fine enough. Coffee filter papers tend to range from 10 to 30 µm but aren't standardized. The Whatman #1 filters that Gray Wolf and myself use are rated at 11 µm with a 98% retention efficiency. Anything finer isn't necessary, unless the lipids haven't been given sufficient time to fully agglomerate.
The temperature is important but so too is the duration of refrigeration. The temperature doesn't need to be lower than -20°C to get decent separation as such but a colder temperature does increase the level of separation aswel as the rate of separation. As the solution cools it reaches the cloud point or wax appearance temperature (WAT), which is the point at which the wax crystals first appear. If the temperature remains at this point, the crystals will continue to grow but may not accumulate enough mass to precipitate to the bottom. If the temperature of the solution continues to drop, longer chained waxes become insoluble and agglomerate readily with the crystals already present. The further the temperature drops, the larger the agglomerates become and the faster they precipitate to the bottom.
While the agglomerates will be smaller if chilled to -20°C rather than say -35°C, they will still precipitate to the bottom with time. It just requires more patience. Of the various scientific papers that I read during my research, the temperature ranged between -10°C and -40°C and most typically between -25°C and -30°C. The colder the better, within reason but anything close to -20°C will suffice. This is particularly true for butane extractions of cannabis, which are much less waxy than most concretes. Ofcourse, chilling the alcohol is really just an additional step towards perfection and not at all necessary. Jump routinely redissolved his BHO in ethanol quite some time before I mentioned chilling and his specimens were incredible. Anyhow, it's been good talking with someone who takes such a keen interest in the matter.
gunna
I'd be interested in reading the source info you mentioned in this post. Trying to educate myself as much as I can on wax's and variables.
On another note ... does anyone use d/i to speed the process? Also as for filters, I filter out charcoal by rolling up a tight rod of toilet paper and rip it in half ... cram it into a funnel end with ripped end towards solution being filtered. By keeping everything in a cryo enviroment, like a cooler with a lot of d/i in it, the solution will filter almost like a wick. I wonder if this same idea could be applied to filtering out wax's. Thoughts?