Attempting my first 2nd pass.. what to expect?

I’m attempting my first second pass I might distillation machine. I have about a hundred eighty grams of first pass distillate and I’m using a 500ml short path. I was running the biggest load I’ve ever done and I had to do two first pass batches, well I my second batch I didn’t clean out the boiling flask cuz I assumed THC he would be in there. Instantly I saw my reflux with a darker tone right after the first couple minutes of my run. I got a couple of shades darker distillate on my second run then I did my first.

My question is what can I expect in yield and is 180 g enough to run in 500 mL without too much loss.

Is the gracian something to worry about, ipull about 400 Mike rounds first pass.

Wood a lle wash be a better option? I’ve read much on that but have no experience on it.

The after taste/smell of this distilate is why I’m even wanting to so this. I’ve always have it but it puts much of a cough and rubbery taste to it.

If you have flask and head well insulated the 180gr should do yust fine
A second pass is your best option and the standard

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Ramp up your temperatures slower on your second pass, you won’t have to get as hot. If you know what
mantle temperature your main fraction came out at from your first run, I would guess that it will come out maybe 10 degrees lower. This will be in part because you should get a much deeper vacuum without all the extra garbage in the system.

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Should I run with cold trap on second? From what I understand the cold trap will reduce vacuum with the cold but will it be needed? But less over space would that be better?

Never run without a cold trap, the colder the better.


Hooked up my cold trap wasn’t pulling down low enough. I’mstaring pulling heads @ 180 about 300 micron. Waite dabout 20 mins then went to 190. Started getting thicker waited 15 mins. Then went to 200, once I got to 200 i started swirling, changed over and noticed my micron slowly going up. Now sitting at 600 and slowly rising? Don’t know what’s going on

What to do with the remainder in BF? Rerun next time ?

When I run 2nd pass, I usually am below 90 microns during mains, with a slightly lower vapor temp than first pass ~160-165C. I typically yield 85-90% weight of starting 1st pass. I always use a cold trap.

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Hey tet! Thanks for the response, think I just have a vacuum problem. Flushed it 3 times before run and just got worst. :unamused: Still pulling mains but a@215 so about the same as my first pass. Don’t know what I’m acheivong here tbh. Got some heads out though. Is there a time when you know when to pull to tails and should I increase temp when I’m close to that point?

I’m still not too confident as to when to swap to tails, but things I look for are a drop in vapor temp and vacuum pressure. Assuming the volume of mains looks good, I will use those as indicators as well as the color of the disty getting darker.


Yea btw I remember reading something about you asking about reusing the gunk in the BF. Yea don’t do that lol learned my lesson real quick

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