@fatawa I truly believe it's the moisture filter in my pump. I have done many runs and haven't changed it. Jolly rancher had a spot on it that I just broke off. I did the shark after and it was really bad... And then m39 that has spots in it. I did m39 last week and I actually cranked the temp up to 120 because this stuff is harder than grandma's purse candy. This time I only had it at 105.
Moisture filters absorb and hold as much water as they can and then they are just a water storage container. We used molded filter inserts, which we replaced daily and recycled by vacuum/baking overnight.
About once a week, we inverted our LPG storage tank and blew out any accumulated water by opening the vapor valve.
Butane is generally regarded as safe (GRAS) and a Class III solvent by the FDA, with a residual standard in food or drugs of 5000 ppm.
We get to about 375ppm in about 4 hours starting with Cotton Candy, processing it at its "just molten" temperature, usually around 110F to 120F (ave 115F). We process at that temperature because it is the temperature where the surface tension of the puddle is low enough for bubbles to readily escape.
Several things cause waxing or auto waxing, but at the core of the matter, as you remove the solvent and the
terpenes, which are also solvents to the diterpenoid cannabinoids, cannabinoids like THC-a and CBD-a begin to precipitate out in the form of crystals. They form around points of nucleation, such as dust particles, and as they grow other constituents not in crystalline form, coat them making the wax grains.
We've found that good filtration and getting the solvent out as rapidly as possible, maintains the highest levels of monoterpenes, because it drives off the LPG, which is significantly over its boiling point and under vacuum, at a significantly faster rate than the monoterpenes, which are under their boiling points except for the vacuum levels.
If vacuum levels are too low, the boiling points of the monoterpenes are lowered to the point that the boil or baporize away rapidly, so we stay above -29.5 Hg, or about 10,000 microns. Boiling off the monoterpenes not only loses aroma and flavor, but leads to auto waxing, if there are constituents still in carboxylic acid form, so that crystals are formed.