Hi all
My question is about micron filtering but also have couple other questions.
First, I was planning on making a batch of hydromorphone but only have the little 2mg pills. Obviously there would be a lot of filler material and thought it would be best to first pre filter using cotton. I have the little dental pellets but they are non-sterile cotton. (I've been using the pellets with no issues yet but want to reduce harm as much as possible). Does It matter much or should they be sterile cotton? Also, since there will likely be lots of filler, would it be better to have a cotton dental roll vs dental pellet? If you spray some isopropyl alcohol on the cotton and let it evaporate, can that potentially sterilize it better?
I was thinking if putting the liquid through a 0.45 micron filter first, and then through a 0.22 micron filter. The diameter of each membrane is 25mm. Are these too wide and may compromise the amount of material I recover? The reason why I thought the larger diameters may be better was that it may be able to take on more particulates compared to a 13mm membrane. Also, is a 45 micron filter even necessary? I thought that maybe the 45 micron would take on the brunt of the particles, thus leaving less for the 22 microns to take. (I had been using the 13mm diameter filters but that was only for small doses.
I hope this doesn't sound too confusing and I appreciate any advice I can get from anyone.
Thanks
Sorry I never replied to your question in the other thread. I meant to, but I lost track.
How much do your hydromorphone pills weigh? From my experience with 110mg pressed fentanyl pills (M30s/blues), the binders will completely clog up a 0.45um filter if you don't pre-filter in some way. You can use multiple 0.45um filters if you like, just try to guage the pressure you're feeling on the filter membrane and stop before it's too late.
Unfortunately, you kind of have to learn the "touch" for this point by trial and error, but essentially, you shouldn't have to squeeze down on the plunger all that hard. It's better to use an extra 50¢ filter than lose a $?? shot, right? Regardless, prep everything over a plate or other solid surface in case the filter explodes.
One way to pre-filter without losing much is to use a thin-gauge insuling needle (like a 30g) to strain off the solution from the top, after you've stirred the powder in water and let it fall to the bottom. It will clog before letting in any massive chunks of binder, keeping them out of your micron filters.
But a RYO cigarette filter works better; soaking and re-soaking the filter can recoup most of the losses in strength IME. If I understand right, the cotton dental roll should be a lot better than the pellets, more like the cig filter (denser/firmer). I'd cut about 1/8" off the roll and use that as a starting point if you decide to pre-filter this way.
IMHO, the 0.45um filters are essential for anyone filtering solutions that are relatively particulate-heavy. It is quite a bit slower to clog up than a 0.22um filter, so there's much less pressure in general and it's less likely to burst. They are quite good on their own, too, and even filter out a fair amount of bacteria.
With black tar heroin, I don't pre-filter at all. I cook up ~0.5g and draw the solution into a 25g 5/8" tuberculin syringe, then I front-load into a 3ml Luer lock barrel. I screw on the 0.45um filter (needle attached) and push the solution through into the front of another barrel. Then I screw the 0.22um filter on that and push it through into the barrels we're going to shoot with.
Even with the tar (let alone pills), a 0.22um would clog up much faster and make the whole procedure more nerve-racking. The 0.45um is quite different and I can even reuse one of them 10+ times (5-6 grams) before swapping it out. (The filters are not ruined after one use or even several, as long as you're going in one direction and not letting them sit forever between uses.)
I've never tried drawing the solution *up* through the filter except once, experimentally, and it didn't seem very good. I'd recommend just pushing it through, FWIW. You can use an insulin syringe to draw up the solution and spray it into the 3ml barrels if you like (as I do), or you can stick the needleless tip of the 3ml barrel into the solution and draw it up direct.
Hope this answers most of your questions, let me know if some are still unanswered. Good luck! It's definitely 100% worth the effort.
EDIT: And no, 25mm is what you definitely want for pills. That is basically the standard-issue size, though the 13mm worked for 0.1g BTH shots and would be ideal for ECP single servings.
You can flush the filters with water to make sure there's no solution stuck in there. Personally, I always flush the 0.45um with 1/4-1/3 the amount of H20 that I used to cook the shot. This is also good because it cools down the solution (though you won't use heat for pills) and gets particulates to fall out again AFAICT.
With the 22um filter, I don't usually flush with water, I pull the plunger out of the back of the barrel and push it down to basically flush it with air pressure, which clears out quite a bit of trapped solution IME.