I received the 1 micron poly filter felt in the mail and set out to try it on a batch of "Billy Bud" that was ready and waiting. Expecting considerable flow resistance, I set up the vacuum filtration system and poured the flavor saturated solvent in but what happened next surprised me. I never got to turn the vacuum system on because the PG drizzled through the 1 micron filter felt just as fast as it does through 5 micron felt. With gravity alone 60ml took maybe 5 minutes to filter through. At first I thought the mechanical seal holding the felt was somehow allowing solvent to bypass the filter. I re-seated/checked everything and repeated the process but ended up with the same results. I decided to use a larger piece of the 1 micron felt folded into a cone and set inside the mouth of a large canning jar, but as I poured the solvent in it began drizzling right through. I could be wrong but seriously doubt this felt is retaining particles anywhere near 1 micron in diameter. Having lost confidence in the felt's retention rating/efficiency, I mounted a 2 micron qualitative filter paper in the vacuum system and poured the same solvent in but this time no drip. I turned the system on and under vacuum it took about 5 minutes to filter the batch. Even after all the solvent had processed through, the now dry filter paper was still so "tight" I was able to maintain a respectable vacuum against it. While the 1 micron filter felt was a complete bust, the Billy Bud turned out quite delicious!
I also used some 5 micron felt and had the same result. It went through it in no time, 10 minutes tops. So I proceeded to go to the next filter stage at 2.5 micron qualitative paper and I think it took 18 hours to run through. Had really good result from that extraction. Finished up a couple more extractions over the last couple of days and all have been good. Staying with paper filtering on them. I gotta tell ya, in the light of any new FDA regulations that may come along, unless they outlaw tobacco and pg/vg I think I'm good to go. Even if nicotine becomes an issue, I think I could get by with 0 nic using these extractions. The flavor is just fantastic and that's really what I'm after. I finally was able to quit smoking after all these years and what do you know, I've found a new obsession with tobacco!
Both of your results carry implications that seem to me rooted in common sense, namely, that a difference exists between the polyester felt filter material and lab-quality paper filters. Personally, I've had good results from the 5-micron poly felt used in my French Press---my extracts have clearly improved performance over those I made last year that were filtered with the paper coffee filters (10-30 micron pore size) I used originally. Generally speaking, over the year-and-a-half I've been doing macerations, my extracts haven't been heavy/fast coil crusters and wick gunkers, but they've never been squeaky-clean, either. I guess I'd say that they've been about average for macerated NETs.
Despite the obvious improvement I've achieved with the 5-micron poly felt, however, I wouldn't defend that "5-micron" rating as accurate. I read an article on filtering somewhere online stating that some filter material was more uniform than others. I assume the poly felt to be the less-uniform type, where the particulates removed are spread over a range of sizes, with the rated pore size of the filter material representing an average rather than an absolute. From Str8's experience, it appears that the 1-micron poly felt is a bogus rating. I don't do straight-PG solvent in my heat-assisted macerations, preferring a blend of PG/VG, and I always use two layers of 5-micron poly felt in the French Press, so perhaps the thicker viscosity of my solvents combined with the double-layer filtering provides greater resistance and the accompanying sense that I am indeed filtering more finely. I don't know. The proof is in the pudding, of course, and the various people who have vaped DIY NET juices made from my extracts seem happy with both their flavor and performance.
I have a heat-assisted maceration batch going right now extracting five
Cornell & Diehl pipe tobacco blends---one English, one Aromatic, and three Non-Aromatics. Since I'm running low on PG, I used 90% VG thinned with 10% distilled water as solvent for this batch. Diane at
MyVapeJuice is the only NET vendor I know of who does in-house macerations using 100% VG, and I've been curious to try that. I'm also using less tobacco (1/2 ounce) with less solvent (80ml).
The cook is at the end of its second day, and the solvents are all nice and dark, so I'll probably end the maceration in one more day and filter the extract, although I'll test sample a bit of solvent from one jar to be sure they're ready. For filtering, I'll use one layer of 2.5-micron Ahlstrom filter paper held in place in the French Press between the plunger's wire mesh and a layer of 5-micron poly felt. The amount of physical resistance I encounter during plunging should tell me something. I'll weigh in about the results.
can't wait to sample it (its the one in the middle).
