I've grown weed for over 37 yrs and I've done BHO many times Mine always came out beautiful and full of flavor and smell. The first thing I can say is be careful man!! I've seen too many people blow themselves up. Here's my method from start to finish. It's simple, cheap, basic, and doesn't take all that long. If it helps, great, glad I could help, if not, don't use it. It's always worked wonders for me. I do use vaccuum, but its a cheap home made thing and is easy to make.
First, I don't freeze or dehydrate my buds/trim in any way other than when I trim sugar leaves off my plants I throw them in a bucket where they may sit for up to a week or more until I harvest. I keep the bucket out of direct light and uncovered so they dry out quite a bit, but when I harvest, the super wet sugar leaves are mixed in so it all evens out. When extracting, I take all of the trim and place it in a home made extraction tube that I made. It is about 2-1/2" to 3" in diameter and about 12 inches long (not to brag). It has two screw on end caps. One of the end caps has 6 or 7 holes evenly drilled in it, the other has a single hole in the center. There is a piece of fine mesh screen inside the end cap with the multiple holes to make sure no flakes get through. You know in the caps of the butane cans they have the pop-out adapters? I use one of those in the single hole so when I insert a butane can it sprays into the tube and out the other side. I use at least 2 or 3 coffee filters over the end cap with hose clamps. I prefer unbleached filters, but the white ones work too. The tube holds just over an ounce comfortably. I fill the tube as full as I can without packing it tightly, but with little airspace left in the tube. With both end caps screwed firmly in place, the trim is ready to go.
I extract into a pyrex dish that is floating in hot water, as hot as I can get out of the tap. When placing the pyrex into the bucket of hot water I am careful not to get any water drops in the pyrex. I do this out in the center of my backyard, as far away from anything as I can be. I also drive a rebar spike into the ground and hook a ground wire to my arm with a velcro strap to make sure I don't create a static spark. My pockets are empty, my cell phone, lighter, and everything else from my pockets is in the house and no one is allowed in the yard with any electronic devices at all. I never extract indoors. No radio is playing, nothing that could possibly create a spark. I've even gone as far as unscrewing the lightbulbs on the patio. When extracting you are sitting in a massive cloud of explosive gas, don't f*ck around. As I run the butane through the extraction tube and it begins to pour out the other side, when the butane hits the warm pyrex it begins to boils off immediatly. This way, by the time I'm done with the extraction, most of the butane has already boiled off. I allow the air to clear and take the bucket ands pyrex inside. For the next 12 hours or so hours, I keep the pyrex on a heating pad so that any excess butane is allowed to evaporate off. It's not all out, but the majority is. With BHO you have to be sure to get all the butane out as it will make you do the funky chicken if you smoke it, and not in a good way. I leave it overnight anyways. The next day I scrape it all up with a fresh clean razor blade and put it into my vaccuum purger, which is a small mason jar with a one way air valve that I salvaged from and old blood pressure cuff bulb I found, siliconed into the center of the lid. This valve connects with regular aquarium pump air line to a handheld vaccuum pump that I got for $20 at Autozone as part of a brake bleeding kit. It's the only thing I paid for. Everything else was scavenged. With the lid secured tightly in place I pump up the vaccuum and let it purge for several hours. When I pump up the vaccuum the concentrate inside the jar swells up like a marshmellow in a microwave. After a few hours I release the vaccuum and it goes back down. I then purge it again, and again, and probably one more time. Then when I am satisfied that all the butane is long gone, I purge it again. If needed, I might dissolve it in alcohol and then pour it back into the pyrex and on the heat pad. When all alcohol is evaporated, it's a nice shatter that is ready to winterize. Always smells and tastes wonderful and is stoney as hell.
This is the basics of how I"ve always done it and I've always had good results. I know there are better ways and safer ways to do it, but this is what I am comfortable with and can afford. I am no master by any definition of the word. I've been doing it for awhile and I've picked up a few things, but there are many who know more than I and I am sure that some of them will tell you that I am an idiot for posting this. I am only relaying what has worked for me in hopes that someone else gets something usefull from it. Take it for what it is.
I can't stress enough that I am not suggesting this to anyone. BHO extraction is very dangerous and even though I do it myself, I know it's life-threatening and accept the risks. Above all else, if you are going to do a BHO run, BE CAREFULL! Another point or two worth mentioning,...I always use a higher quality butane that has been filtered or refined many times. Also, It's a good idea to dispose of the empty butane cans as soon as you are done. Don't let them pile up or fill up a bag first. ALL BUTANE MUST BE PURGED COMPLETELY!! If ingested or inhaled, Butane will act of your nervous system and can have some extremely serious, if not deadly effects on the human body. Better safe than sorry. BE CAREFUL!! BHO extraction is scary stuff.
Good luck and I hope some part of this does you some good.
~E
