Trouble with new 10l short path.

What’s up gang

So I have been running a 2 liter system for a while and have it dialed in pretty well. As a circulator I was using a bucket heater and aquarium pump but just ordered (Chinese supplier) a 10L turnkey system that came with a vacuum pump and low temp circulator

I am struggling to get the circulator above 35 degrees Celsius. Even when I make the set point 100 degrees it won’t go over 35. I am using 710spirits ethanol/heptane mix as my medium.

Past that the mantle over shoots temps like crazy and seems to have a better chance of stabilizing under vacuum. Either way I was pulling ridiculous vacuum on the system -30hg on my gauge and had to scale my temps all the way up to 267 degrees before getting a reaction. Can anyone make any suggestions or give me some questions to answer to help you help me? Here’s a pic of my setup

Uploading: 2506A582-66D8-4E20-A828-28D0BAB313FE.jpeg… Uploading: B1BD8A80-9EFA-4881-A077-042D031DEC92.jpeg…

Your going to want to empty out that ethanol from your chiller/heater since ethanol’s boiling point is 78c. Having it set that high is pretty dangerous as it will start boiling and vapor could ignite.

Look into getting some heat transfer fluid for it or even just propylene glycol will work, PG has higher boiling point so could be used for hot condenser tek too but it’s likely your heater/chiller doesn’t go up that high and you would need a recirculating heater instead.

Second thing you need to change is your vacuum gauge, really need something that reads in microns, readings like -30hg aren’t helpful when it comes to short path distillation. Most people use the bullseye gauge but there is a cheaper one available on amazon called the supco vg64.

Also your going to want to wait when uploading images until they finish as your pics didn’t upload and you just posted the “uploading” text.


wtf would you do that?
do you WANT to catch fire??

Alcohol works fine in a chiller… and is great in the -60C to -70C range where other things are problematic, but asking your circulator to turn it all to vapor and then keep heating is a recipe for disaster!!

You’re lucky it disobeyed…

Score one for cheap junk :rofl:


Here comes da-boom.


Dont use pg for hot condenser tek. A good fluid is gonna cost about $1100 for 5 gallons and you shouldn’t need to replace it unless you get it too hot (200c <) , then it will turn into a gel and your heater will catch on fire (how do I know this?)

Also, you need a vac guage that measure in microns not hg


First: There are many button on those chinese equipment, make sure you pressure the “heating” bottom. Those unit are not intuitive to use. Some time they have one button for “chilling”, one for “heating” and one for “circulating”.
Second: Use silicon oil before you burn down your house.
Third: Where did you read your vacuum level? From your own gauge or from a gauge they provide? Temperature should never be that high for short path. You are burning your glassware.
DM me if you need any help. Your uploaded photo is not showing.


Yeah I know it was probably not too smart of me to do what I did with the chiller but to be fair I watched it the entire way and set it to 50c (far below boiling point of ethanol) and it maxed out at 35 degrees. That’s when I scaled to 100 for shits n gigs to see if I could get it any higher and kept my eye on it the whole time.

I use my old vacuum pump oil for my heating fluid. It’s got a high smoke & coke point + I already paid for it lol.

Not sure the compatibility in your chiller though.


My man!

How about some avocado oil? I know there are plenty of people using high smoke point cooking oils has their heating bath fluid



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Flash point of various oils


To my novice experience… 267 degrees is way far beyond what you should be anywhere near. As for the vacuum, I have a cheap old shitty orange vacuum pump I use for my oven that pulls to -30hg. For my spd the cheapest functional pump was the welcho duoseal which was over 1000 bucks, along with a few hundred dollar vacuum gauge. My guess is your hardware is not sufficient. Def need a vacuum gauge.

What hardware did you change from your old 2l setup besides glass and mantle. How were you pulling and reading vacuum
Before? Maybe post a specific parts list and someone here can make a better suggestion. Good luck!


Hmmmmm I do have lots of old oil laying around but yeah I’m not too sure if my chillers components would appreciate that. Not to mention my chiller only works from room temp to -10 degrees.

Anybody have experience using the poly science recirculator?

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It’s pretty easy to check the seal compatibility. I’m 95% sure you’re not gonna run into issues using your old pump oil but I haven’t bothered to do your Google work :stuck_out_tongue_winking_eye:


Like I mentioned it wouldn’t really matter because my circulator doesn’t achieve the temps I need to do a run.

With that being said why would a chiller/circulator that can only do ambient temperature down to -10 degrees celsius be included in a short path distillation system? Does ANYONE ever run their system with cold fluid going through the condenser? I would imagine if the condenser was cold that the distillate would essentially just freeze and clog up the path way…Anyone have anything to say about this?

Are there certain compounds that require incredibly cold temperatures to condense?

When running my system I thought I noticed little specks in the air being pulled by the vacuum pump…

Im wondering if possibly the vacuum is pulling so hard and so fast that it is literally pulling distillate all the way through the system without giving it a chance to condense back into a solid… Just a thought. I dunno.

265 means you have a bad vacuum setup, bad mantle heat management, and leaks throughout. You can’t just ask what the problem is without noticing the three items that cause this issue. My telle is 408-348-7264 and I can hold your hand and walk you through it while you assemble and service your pump and short path to avoid this error. At those temps you may have damaged some material so doing a short bed silica 60 pull will remove the degraded compounds and allow your next distillation to opperate better.


Is this a troll thread?
It seems like your doing everything wrong that u can.


This thread is more than mildly concerning.

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Hey I have been having some trouble running my short path. Would you mind if I got some advice from you? over Telegram as well?