Right. This started out as an idea after I used a caffetiere to make BHO and the pyrex part of it shattered when it was coming back up to room temp.
Add to that the fact your fingers stick to it because of the cold and you can understand the idea behind this.

I bought a 1Ltr stainless steel thermos flask from (As*a) for £3.89 and had everything else to hand.

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To make this you'll need.

1 x Stainless thermos flask of your choice

1 x Drill and 5.5mm metal bit

1 x Pack of coffee filter papers

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Step 1: Mark the center of your lid/cup with a pen or a punch.

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Step 2: Take your drill and bore a 5.5mm hole through the middle of your mark.

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Step 3: Drill 2 identical holes on either side of the central one, these are for ventilation, otherwise it builds pressure and blows the top off (found this out through trial and error )

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Step 4: Put one of the attachments from the lid of the gas can in the center hole

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Step 5: Fill your flask to the desired level with plant material/bud

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Step 6: Empty enough butane into the flask to cover the plant matter and give a shake/mix around. If you screw the top on you can shake it as it has a rubber seal.

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Step 7: After waiting your desired amount of time (20min in my case) carefully pour the butane mix out of the flask through a coffee filter held by something (kitchen tongs here) into a flat bottomed bowl.

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Step 8: Sit this bowl in another larger one filled with hot water till the butane has bubbled/evaporated off (you might need to change the water, I did)

Step 9: Scrape all the oil up out of the bowl using suitable impliments. I use a fresh stanly blade, a teaspoon and some isopropanol alcohol.

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Step 10: Sit back and look at your lovely Butane Honey Oil. Roll a fatty or grab your bong, this will blow your mind.


This is only the Mk1 BHO Flask. I'm going to make a few design changes inc a filter paper holder for the inside, to allow it to do everything integraly.

Let me know what you think about it and feel free to add any comments good or bad.

If you have any questions then please feel free to ask.


Cheers
Nirex

very nice indeed

great idea that.. nice one.. occasionally see these flasks for a couple of quid in camping supplies or home bargains..actually cheaper than a cafetiere

You said you can shake the flask if you put the lid on.. does that not cause a huge pressure build up inside?

might have to make one of these meself.

That's very cool Nirex.

For the BHO I'm still to make I was thinking of using an insulated mug instead of a caffetiere. I've got an old mug that was about a quid from Safew*y which I was gonna use, and seeing your luck with a thermos has made my mind up. I was a little concerned about the lid on my mug... but the drinking spout and steam hole will be more than enough if you got away with 3x 5.5 mil holes.

I was going to put my mug in the freezer for an hour or so first, to minimise the butane lost to evaporation.

Oh, and can you say which shop you got your coffee filters from? Was it As*a when you got your thermos? The filters are the only things I don't have, and I can't find them anywhere (well, W*ittards o* Chels*a have them, but there isn't one of their shops round here [though I think they have gone bust recently, so the stores might have gone the way of the Woolies Mammoth], and on their website when I looked a few weeks back they were £3.50 for 4, or something rather obscene).

Cheers. Enjoy that oil, it looks sweeeet

You can find them in most supermarkets i believe, just in the coffee section. I know for certain that S**nsburys do them, or at least the one near me does.

E2A: Nirex, how much plant material did you use? Was it just trim/popcorn buds? How much oil did you end up with? Looks excellent, really need to try this method!

Hi Nirex, I've been using a thermos flask for extraction for the last two years. I might have even been the first to use a thermos although I doubt it; someone must surely have thought of doing it before me, although I've never read of them. I think you, like me thought of the idea by yourself. After all, if you're familiar with butane extraction, it's not hard to look at a thermos flask and see the potential. I'm suprised that more people haven't thought of the idea before.

I first thought of the idea because I was looking for a way to extend the extraction time with butane, by delaying boil off. At the time I was familiar with the fact that liquid gases like liquid nitrogen were stored and transported in vacuum/dewar flasks (thermos flasks) and could keep the gases liquid for days if necessary. With this in mind, I decided to try using a thermos flask for holding the liquid butane.

The method worked very well for keeping the butane in liquid phase for extended periods of time. So much so that after the initial boil off from the butane cooling the flask, all evaporation stopped completely. The lid was left off but the vacuum filled walls of the flask were sufficient to keep the butane insulated from the outside. Indeed, I left it extracting for over an hour the first time and might have overdone it a bit because the oil was brown, although the buds were very old and the resin glands were all oxidised and brown, which wouldn't have helped.

I mentioned that I left the lid off the flask. Instead of ruining my flask lid by drilling holes in the top, I decided to make a small hole in a jam jar lid and placed that over the top of the mouth, to inject the butane through. These days, I extract the buds twice. I do a very quick wash with butane in a cafetiere for the lightest grade and then do a second much longer wash in the thermos, to extract every last morsal of oil from the buds. Take a look at my old thread if you like.

http://www.uk420.com/boards/index.php?showtopic=73723

Gunna

Due to the nature of a thermos flask the liquid butane will not really expand a huge amount once the flask is sufficiantly cold enough. It does build up a slight amount of pressure but that can be combated by putting the flask in the freezer for an hr or 2 before hand

Yeah, got the filters from As*a. They were in the coffee aisle next to the filter coffee.

They only cost around £2 and you get 40 in the pack. Made by Do*we Egb*rts. They're made from unbleached natural paper too for that added purity!!!

I had 2 x large ziplock freezer bags full of trim and popcorn buds.

Did 1 run on each bag using 2 x 300ml cans of London Butane (Zero Impuritys)

Ended up with around 4g of golden oil

All gone now tho

Hi mate. I kinda guessed that someone would have done it before.

But after I spent a day looking around B&Q etc looking for suitable materials to build an extractor similar to the honey bee and had no luck. Then was looking at teapots and caffetiere's in As*a my eyes were drawn to the thermos flasks and a light went *bing* in my brain. From there on it was very simple due to my mechanical background.

As stated above I'm going to look at refining the design slightly to make it specificaly for this purpose with an internal filtration system.

Will post pics once I get around to starting the mk2 build.

Some stainless steel mesh and some screws should do the trick. You still have your cracked caffetire, right? Use the SS mesh on the plunger as material perhaps.

Gunna

Nah mate, I chucked the caffetiere as it propperly exploded when it was coming back up to room temp. Made some horrible groaning noises then spectacularly blew up.

I've edited my post because you posted a second or two before me. It's probably cheaper to buy a cheap caffetiere at a store just for the mesh, than it would be to buy the mesh itself online and have to pay for delivery. Perhaps some high street stores sell mesh replacements, which would be even better. A small nut and bolt can be used to close the central hole in the mesh, where the plunger rod usually feeds through.

^^^ Above post edited more than once, please re-read.

Red Monkey sell a 3 cup gauze filter for 3.95, including delivery.

Did you use 2 cans per run or just one can per bag? I used this method last week with good results. I did find that the butane would start to leak out from the rim of lid and through the vent holes. Next run i just gaffer taped to seal lid to flask then just stopped gasing for a sec when it started to come out top holes. Only half filled flasked with bubbled re-dried trim. Resulting oil is in the freezer now so i'll post some pics in the week. To finish, this is such an easy and safe way to do it everyone should have a go. The hardest part is scrapping the oil up
Planning on making jelly and some of this budder stuff just for easier handling and storage.

Right.

I've found the flask filled 2/3rds of the way up needs 1.5-2cans to cover the trim fully.

I've not noticed the gas leaking out the rim............possibly slighty differing flasks from each other.

I also agree with you that the hardest part of making bho is scraping up the resulting yummy-ness!!!
I use pure iso in a little pump spray bottle to make collecting the oil easier, gets every last drop off the bottom of the dish.

Now that I will have a load of trim from this crop in a few weeks I am going to start work on the next instalment in the Thermos-X-tractor.

Thermo-X MK2

Will be working on an internal filter system for this one along with a couple of other tweeks and revisions...............

Pics and details to follow.

Cheers for the replys in this thread and all the pm's and comments I've had in live chat about this system.
The next installment will hopefully address some of the niggles and issues that have been highlighted in the first prototypes.


...........To Be Continued

It sounds like you've come up with a brand name. I should have patented the use of thermos flasks for extraction and sold you the rights!



I'm looking forward to seeing the new design. The stainless steel mesh filter in a cafetiere would be useful for making a filter for a thermos. Inventing stuff is fun isn't it?

gunna

Bit old now but it is method better than say when you run the butane straight through? instead of letting it stand or will you get a much nicer oil if you run straight through?

The quicker the extraction, within reason, the cleaner the oil but the less oil aswel. If you want quality and quantity you either compromise by finding an extraction time somewhere in the middle, or you do a quick extraction followed by a long extraction to give two grades of oil, or more.

I am going to give this a whirl on my next crop, just two things, can you use just the trim and air buds and still have nice BHO? and also as I have never used it before do you roll it up when it's soft into sauges to add to spliffs? Cheers.

Would sitting the container you are evaporating the butane off, on a hot water bottle work just as well as sitting it in a pan of hot water?

i would think so mate, though it may take longer than if it was in a bigger bowl of hot water

i found that the butane in the dish cools the water really quickly.(as its boiling temp is only 31f or 0.55c) .maybe a electric or usb cup warmer would be better for evaporating

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