Thermos project, need advice

[CannabisTHC]

Also beware of thermos containers plastic coated on the inside .

That's good to know!

I was wondering about the plastic in the cap as well as the inner button lid even though I know you set aside the button lid. I found out what kind of plastic they are. Supposedly the screw on lid below the top cap (one with button) is Acrylonitrile butadiene styrene which should not be used because it is reactive with butane. Where as the black plastic that is in the top cap is Polypropylene which you can use. My only question would be that plastic piece is probably glued into the cap, no? If so it seems as though when you filter the butane out of the top cap it would come into contact with that glue after you've drilled the holes? would this be an issue?

I'd prefer to buy a thermos without any plastic or take the black plastic off. I did find a thermos without any plastic but it was a bulk order from china.

 

[Gray Wolf]

That's good to know!

I was wondering about the plastic in the cap as well as the inner button lid even though I know you set aside the button lid. I found out what kind of plastic they are. Supposedly the screw on lid below the top cap (one with button) is Acrylonitrile butadiene styrene which should not be used because it is reactive with butane. Where as the black plastic that is in the top cap is Polypropylene which you can use. My only question would be that plastic piece is probably glued into the cap, no? If so it seems as though when you filter the butane out of the top cap it would come into contact with that glue after you've drilled the holes? would this be an issue?

I'd prefer to buy a thermos without any plastic or take the black plastic off. I did find a thermos without any plastic but it was a bulk order from china.

Mine all have stainless lids, so I'm not visualizing exactly what you mean, but I wouldn't use styrene where there is any possibility of contact with the butane.

If they are exposed only after drilling the holes, I would drill holes in another lid and just set it on top of the thermos for injecting. It doesn't have to fit.

 

[gunnaknow]

As GW said. I usually use a jam jar lid with a couple of holes in it, placed over the mouth. Also, if you choose to use the thermos cap as the injection point, you can simply remove the cap before pouring off the butane.

 

[CannabisTHC]

Ok great thanks Gray Wolf and gunnaknow.

Here's the thermos that I have, what I was talking about was the black plastic is polypropylene and the white plastic is styrene. It seems like almost all thermos's are like this that I've seen on the internet lately. I wanted to use the cap so I could place the coffee filter over top the cap and screw it on to filter and I guess I could since it is polypropylene, but I'll just do it like you guys have suggested.

 

[gunnaknow]

You can fasten the filter paper over the mouth itself if you wish but I prefer to pour it directly into a filter. If you pour slowly, most of the bud/trim will remain in the thermos. If you don't have a funnel, you can make a filter holder with a wire coat hanger and some clothes pegs. Pic by grobag.

 

[Gray Wolf]

Yeah, I dump it through a Chinoise wire strainer into the paper filter or don't use a filter and wash the unpurged BHO oleoresin out of the container with ethanol and go directly to winterizing.

I filter it just before winterizing and of course, afterwards, using a coffee filter or a vacuum assisted Watmann #1 lab filter..

 

[gunnaknow]

Great minds think alike, GW. When I'm making an absolute I pour it through a SS strainer and run the ethanol solution through Whatman #1. I think that you prefer to use the paper in a Buchner funnel. For anyone who doesn't use a Buchner, it can help to pleat the paper, or buy Whatman prepleated grades.

 

[CannabisTHC]

gunnaknow that was the trick knowing Buchner funnel, helps for searching, good to know to pleat as well!

GW, It looks as though you have a vacuum pump hooked up to your Buchner funnel? I've been trying to figure out how to do that because I'm sure my Refco 2 stage 5cfm pump is too much lol. Will the venturi effect on an aspirator work with the Buchner funnel?

Thanks again!

 

[gunnaknow]

Canna, you wouldn't want to pleat if you're using a Buchner. A Buchner funnel is designed to be used under vacuum with a Buchner flask, otherwise known as a side-arm flask. You wouldn't usually use a Buchner funnel without a vacuum but it could be used for gravity filtration. I'll leave the other question for GW, as it was addressed to him. He's good at answering such things.

 

[CannabisTHC]

Ok, yeah I know what the Buchner flask is just didn't know what it was called before you said it. I'm not planning on using gravity filtration, sounds like you can use either a hand vacuum pump or a water aspirator.

 

[gunnaknow]

Ah right, I thought that you were asking if a vacuum was required. Atleast you now know what it's called, which could help if you're looking to buy one.

 

[reefsauce]

speaking of buchner funnels; I just got one off amazon not too long ago haven't used it yet.

the rubber stopper/seal bit came all pre set up to seal the 2 parts, but I am a bit concerned by the strong nasty rubber smell coming from it. Is that normal? Seems like I can push the buchner funnel in far enough so a bit of the glass tip is extending all the way below the rubber, but I'm also worried about vapor attacking that seal.

anything to worry about?

 

[gunnaknow]

Reefsauce, the rubber stoppers often have a smell to them when they're new. You don't need to be concerned about vapor attacking the seal, as the rubber is very resistant to both ethanol and iso. There will be little to no vapor from the chilled alcohol anyhow.

 

[reefsauce]

Well I did my first attempt using the Buchner funnel last night using QWET. It was a complete failure. As soon as the vac came on, the liquid dripped down the funnel to the tip, then back UP the outside of the tip, across the robber stopper, then down the sides of the collection vessel. Obviously a bit of liquid got sucked into the vacuum, but probably only a drop or 2 before I shut it off.

I had only gotten maybe 100ml of ethanol into the vessel. I inspected the robber stopped and it was clearly being dissolved as there were tiny black specs streaming down the glass into the solution. So I threw that out and was able to save over 200ml that hadn't yet gone through that filter and just coffee filtered.


Where did I go wrong? I made the funnel tips extent past the rubber stopped, but the tip of the funnel is slanted, and I only had the very tip past the rubber, some of the shorter part was flush or a bit less.

Will this be avoided next time if I stick the funnel further through the stopper so the entire thing is sticking out?

I read some guide that says its recommended the funnel extend into the collection vessel past the vacuum elbow.... well that's not possible with the vessel and funnel I am using.

 

[gunnaknow]

Reefsauce, it might not be natural rubber then as it has good resistance to ethanol. It's possible that the terpenes and/or residual butane are attacking the rubber as many rubbers aren't resistant to hydrocarbons. However, if it's swelling or corroding that quickly it seems more likely to be down to an incompatible rubber being used with ethanol. If in doubt, neoprene rubber is very resistant to ethanol. You can also use ground glass joints. However, if you adjust the tip so that the alcohol doesn't contact the rubber, it shouldn't need replacing. Both sides of the tip should extend past the rubber bung. If the funnel isn't long enough to extend past the side-arm it can sometimes help to decrease the level of vacuum, so that the stream doesn't bend off to the side too much. You should ideally use a vacuum trap to catch any solution that makes it through the side-arm, to prevent it reaching the pump. Let me know if you have any more problems.

 

[Gray Wolf]

Reefsauce, it might not be natural rubber then as it has good resistance to ethanol. It's possible that the terpenes and/or residual butane are attacking the rubber as many rubbers aren't resistant to hydrocarbons. However, if it's swelling or corroding that quickly it seems more likely to be down to an incompatible rubber being used with ethanol. If in doubt, neoprene rubber is very resistant to ethanol. You can also use ground glass joints. However, if you adjust the tip so that the alcohol doesn't contact the rubber, it shouldn't need replacing. Both sides of the tip should extend past the rubber bung. If the funnel isn't long enough to extend past the side-arm it can sometimes help to decrease the level of vacuum, so that the stream doesn't bend off to the side too much. You should ideally use a vacuum trap to catch any solution that makes it through the side-arm, to prevent it reaching the pump. Let me know if you have any more problems.

You may also extend the funnel's effective downtube length, by supporting the funnel near its top with a stand and clamp for stability, and inserting it only halfway through the stopper from the top.

Stick a short length of glass tubing in the hole from the bottom to extend its effective length, and the vapors won't be discharged near the vacuum outlet.

 

[gunnaknow]

I'm having difficulty visualizing how your first tip would increase the downtube length, GW. Could you explain again, as I've probably misunderstood what you were trying to describe. I understood the second tip and would also recommend it as an option.

 

[Gray Wolf]

I'm having difficulty visualizing how your first tip would increase the downtube length, GW. Could you explain again, as I've probably misunderstood what you were trying to describe. I understood the second tip and would also recommend it as an option.

If the Buchner only sticks halfway down through the top of the stopper, that leaves the other half of the hole in the stopper to stick a short length of glass tubing in, and allowing it to extend out the bottom of the hole.

We have essentially used the stopper to splice a length of tubing to the Buchner funnel downtube.

 

[gunnaknow]

Ah, I get what you're saying now GW. Before it read as though you were giving two different suggestions. Using the stopper as a joint is indeed a good idea.

 

[gunnaknow]

GW, perhaps your setup will give him an idea on how to use a vacuum trap.

https://www.icmag.com/ic/showthread.php?p=5592211#post5592211