vapor in recieving flask.

Running a cleaning pass on a tails run. Vapor built up inside the receiving flask, any idea what’s going on? 500ml bf run is at 200c at 7microns.

vac leak or room temp is low

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76 in the lab, tiny leak at head to bf. Maintained 7microns whole run. Just atmospheric moisture? Why wouldn’t it condense in the cold trap?

it’s not interested in flowing over there due to receiving flask temps

How can I seal up the head → bf joint??? Its leaked every run. Its 24/40 I’ve tried grease, disty, ptfe sleeve, and ptfe and disty. Once it gets hot it starts leaking, and I’m losing my shit! It’s an AI head on either a 2l or 500ml bf.

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Silicone wrap tape

Gas line wrapped Male joint
(I’m old and not great about putting links, iirc @cyclopath gor his tape trick)

More distillate ot grease on the joint

New bf is needed

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fixing that neck leak will improve your color and temperatures as well as that pesky vapor.

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close, use ptfe tape instead

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Probably moisture left in the resin, that will come off all with the terps. use a heatlamp in a desklight to heat up your cow and receiving flasks. you will want a dimmer placed inline with the lamp so you can throttle the heat, it will keep your product from freezing up as well. I usually make a heatsheild out of foil to protect the plastic gl connection from melting.


It’s a full bore 2l rig with a 2021i. The vapor only appeared in the recieving flask this run(first run with the 2021i) no where else… :thinking: I’m attributing it to the leak and new pump. Ran a welch 1400 before. Teflon tape should hold vac at heat? This is literally my only issue and its terribly frustrating.

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Personally I’ve had more leaks with ptfe tape on glass joints. Do you do one “ring” or tapered wrap?

The tape works freaking wonders for temp probes though I’ve found out.

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besides the cold traps the receiving flasks are the 2nd coldest regions in the system regardless of its configuration. Try a heat gun on the flask, it will clear up, when you get tired of using a heat gun for a few hours try the lamp!

I usually wrap it like a candycane up the joint, apply hot distillate into the female joint and heat gun it to make it runny, then gently push and twist the joints together. not all glass joints are perfect, the tape helps alot. there are these as well.

these all work