100-250ml short path head question

Hi everyone!

Weed decriminalization is happening soon in my area, so I’m planning to set up a 100-250ml SPD system to prepare and learn. :slight_smile:
However, I’m unsure about which short path head would be most suitable for my needs/boiling flasks.

I’m considering using glassware from Synthware since I’ve seen it being used for vacuum distillations and it seems affordable.
I have a few options for the heads:

  1. “Micro” short path head with 14/23 or 19/26 cones (10/18 for the thermometer).
  2. “Micro” short path head with 14/23 or 19/26 cones (10/18 for the thermometer) with a small Vigreux column.
  3. “Micro” short path head with 14/23 cones (10/18 for the thermometer) with a fixed ~100mm Vigreux column.

    4.Short path head with 24/29 or 29/32 cones (10/18 for the thermometer) and a combination of a cold coil and Liebig condenser.
  4. Short path head with 24/29 or 29/32 cones (10/18 for the thermometer) and a combination of a cold coil and Liebig condenser, along with a small Vigreux column.
  5. Short path head with 24/29 cones (10/18 for the thermometer).

I have a few questions regarding this glassware and the different heads:

  • Is a Vigreux column necessary for achieving good separation?
  • Would it be better to choose the head without a column and use an external ~100mm one, or would the ones with the small column provide sufficient separation? Which option would yield better results?
  • What is the capacity of a micro head? Can it handle a 100-250ml boiling flask, or would it be better to use a larger non-micro head?
  • I’ve heard that grease may not be the best option, and some people suggest using PTFE sleeves. Can I achieve sufficient vacuum using only PTFE sleeves?
  • All the “micro”-style heads are available with a vacuum jacket for better heat retention (I guess?). Is it worth the extra $40, or would cheap insulation work just as well?
  • Considering my use-case, which head would you recommend?

I appreciate your guidance and insights on this matter!

Why start so small? you’ll want a bigger one after the first successful run…

I certainly understand the wish to destroy as little cannabis as possible while learning, I’m just not certain that starting with a rig you know you’ll outgrow the moment you figure out how to run it makes a lot of sense.

not even certain distillate makes sense these days…see: Liquid diamonds is just distillate, change my mind (we haven’t bothered making distillate in the last year).

assuming you decide it IS worth making distillate, AND you decide you really do want to buy a rig you’re only going to run a dozen times, I submit that the head design is mostly irrelevant, you’re going to go buy a different head and a 2L/5L rig as soon as you can get the little one to work…

only PTFE?

nope. add dope…distillate (or liquid diamonds).

You are aware of the need to make “crude” first?

Not all who purchase SPD are: How to make home Crude oil for distillate


I would not bother with any of that.

You want a vacuum jacket style head for cannabinoid distillations. You want to start at 2l flask, however I’ve heard people in the past were using 1l flasks however I’ve found the smaller it is the less controll and quality you can achieve.

  1. No vigs aren’t necessary. They provide a block for liquid but do little in terms of improving vapor separation
  2. I think the head without a column is too small. Liquid would probably run into the condenser from below fairly easily
  3. You can distill these quantities in a simple 1L spd but you’ll need to insulate it. If you go with any bigger glassware without more oil the system will need to be heavily insulated.
  4. Can’t help you there. I use only steel in my systems so that all the connectors are kf style
  5. It’s probably worth the extra $40 to insulate
  6. If these are your only choices I would go with 2 but with vacuum insulation
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Thanks for your input. Maybe a bigger setup would be better ^^

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I was going to give you much longer response but seems like everybody else already did, so I’ll just keep it short and sweet. None of the heads you posted pictures of are appropriate for what you’re trying to do.

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Thank you for your response!

I appreciate your insights and concerns regarding the size of the setup. Let me provide some additional context as to why I opted for a smaller setup:

Given the legal framework that is being planned in my area, the production of cannabis will initially be limited to personal consumption. It’s important for me to stay within the boundaries of the law once the regulations are implemented. Commercial selling will not be permitted for the foreseeable future, and even gifting will probably become illegal.

In light of these restrictions, there are essentially two ways for me to obtain THC in larger quantities once decriminalization takes effect:
growing my own cannabis plants or exploring synthetic methods to create delta-9-THC (like cbd isomerization or something).

Consequently, I will only have access to a limited amount of cannabis, which restricts the volume of extractions I can perform. This is one of the reasons why I am not considering a larger setup, in addition to the cost savings associated with a smaller one.

And yes, I am aware of the necessity to produce crude oil first. :slight_smile:

How can I determine the appropriate flask size for each of those heads? My assumption is that the smaller 14/23 heads are suitable for flasks ranging from 50ml to 250ml, while the larger ones (24/29) are designed for flasks between 250ml and 1000ml.

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24/40 is the most common 2liter and possibly 1liter.

1 liter flask = 500ml roughly loaded.

2 liter flask = 1000ml roughly loaded.

Avoid distilling with anything smaller than 24/40 size neck. Search for 24/40 discharge end, you will encounter less clogging issues.


Ive got some retired small heads, if u wanted to buy something that is a top brand but for a used price.


Hmmm ok so here a my advice

A small setup is GREAT and extremely useful and in your case (legality) a wise step
I think it s the rig I use most but I do a lot of r and d and start with small quantity s
Things to consider and already recomended by some
Get the glass sizing that if you grow still suits ns 24 or ns 29
Althou 29 is more comon in europe
24 is easier to obtain like Vevor.com
But get a size that you will most likely also have when gooing to scale
So not the 14 or 19
Vigeur is not needed stainless steel scrubies (cleaned with acid and acetone) work well
Get insulated version althou you will likely still need additional insulation or a
Heating device (infrared light or heatgun)
Minimum amount on a 1 liter flask is 300 ml on a 500 ml flask 200 and on a 250 ml 80 ml so
On avaerage cleaned spd ready crude
Made from clippings is 60ml per kg biomass hope this helps

Ps get a good 2 stage rotaryvane vacuum pump and if buying new spend some extra so it will be adequate for when scaling to a larger flask
8 cdm I would recomend


Vevor and similar don’t use real boro for the glass. It’s some junky cheap glass that generally isn’t safe and carries severe risk of injury or accident above normal boro suppliers. Keep that in mind.

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You are right to state that the quality is inferior
But in europe getting accounts at the good glass sellers is a thingy
And delivery dates are horrible having to wait weeks for a flask to be delivered is a nuisance
Delivery takes two days if it s available in the polish warehouse

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I’m sure there are vendors all over the world that can help you with safer glassware.

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I have several 2l shortpath glassware sets . Ill sell you a head , boiling flask and cow for a hundred bucks plus shipping. Its all brand new and just sitting around waiting to be used.


So this would be a appropriate short path distillation head for my needs? got that 24/40 size, vacuum jacked and not such a small discharge end :smile:

Thank you, @Lightbulb, for the tip regarding the discharge end size (I believe you were referring to the picture above).

From my understanding, I will require some form of heating for the head to facilitate distillation with small volume flasks. Without it, I suspect that using a 250ml/100ml flask would result in more refluxing than actual distillation, particularly when the boiling flask content decreases. Is my assumption correct?

I’ve been contemplating the idea of constructing a PID-controlled heating system for the head, but I’m uncertain if it’s a good idea or even necessary.
Perhaps sufficient insulation would be all I need?
My plan involves using a high-temperature silicone heating mat/pad (or spiral) with a PID controller, along with a temperature sensor (K-type or PT100 / 1 or multiple) attached to it or something along those lines.

Would it be feasible to use a 100ml flask on a 24/40 head while maintaining proper temperature control?

I have an unrelated question regarding heating. Recently, I acquired a stirring hotplate with a 500-watt heating element (Ø 135mm), a maximum temperature of 350°C, an external probe, RS-485 connectivity, and various safety features such as dry-run detection. (25 bucks :joy:)
I would guess my hotplate is suitable? Additionally, for the heating bath, would you recommend using an oil bath or a sand bath? I’ve also heard positive things about Lab Armor Bath Beads, but they seem difficult to obtain, especially at an affordable price.
I am aware that having a larger thermal mass might increase the chances of overshooting my desired temperature. However, I plan to test a heating cycle with oil beforehand and monitor/log the temperatures.

@Chemistreeclub That sounds great! Could you provide me with some pictures?
The only downside is that shipping costs from the US to Europe would likely amount to around $50.
Nonetheless, it would still be more cost-effective than purchasing new glassware here in Europe.

Thanks again everyone :+1:

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That head is definitely going to do the trick. I would not add heat, just use some glass rope, it’s very common and easy to take a peek.

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Ya europe will be more than that. Yes thats a decent 2l distillation head. Id go with that.

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Yeah, shipping to Europe can be troublesome. There are companies that can provide me with a US address and then forward my packages to me for approximately $60-90 (depending on the package size). However, dealing with customs can be challenging here.

Fortunately, I still have a few months until the new law passes and becomes active, so I have plenty of time to search for the items I need.

It seems that the 24/29 size is quite common in Europe. I already have a few 24/29 flasks at home that I purchased for under $4 each. If I want a flask in the 24/40 size, I can get some from Stoneylab for around $15, or opt for unrecognized Chinese brands for about $10. So, it seems like sticking to 24/29 would be the best choice for me.

In general, it’s challenging to find short path heads with a large discharge end. However, as I mentioned earlier, I have time, so there’s a possibility of finding one.

What do you think about this? Is it worth trying with a lot of insulation? I could get my hands on one of these for $40 ($70 with a cow). I’m a bit concerned that it might bubble over into the condenser.

Also, is there a downside to using a separate condenser and a 3-way adapter? I would assume that there might be a higher risk of potential leaks.

Take a Look at rocco scientific . Its worth the shipping from new jersey.

Let’s start with the real question,
what is your budget?