Damn that’s sexy, what do you run through your condenser?? Why is it yellow?
Also why do you have a tube connected to your bleed vac port?
Just set up this bad boi today while extracting… man was I shaking with all this glass lol… got some stuff still need to buy but I was trying to see how low I could get my vac on my spd with my water aspirator lol😂
Feed tube
Yellow food dye to make sure no keaks.
That’s not a bleed port. That sucks fresh etoh wash Into your bf.
Gonna have to pull out a spoon soon.
on bumping - results from “too good” of a vacuum rather than too poor, a leak could be doing that but itd be on the surge back down to low vac from atmosphere.
so - assuming that your level of vacuum hasnt changed… what has changed?
only you can answer that, but i have a feeling that it has to do with your input. (starting material)
because thats usually the most volatile variable involved here. i mean same pump, same vac, same roto assembly. however the stuff started out as a plant, and that means wildly different kinds/amounts of terpenes, fats waxes and so on.
what is probably happening is that a terpene or other compound that is strain/grow specific is acting as a surfactant i was never able to pin down if it was a pesticide or something within the plant in particular strains, but who cares shits bumpin.
solutions: 1. only fill roto flask HALF FULL.
2. bump flask. https://www.google.com/search?q=bump+flask+roto&sxsrf=ACYBGNQQYqPijzV0HCM3tFdbwP3cQWlF7A:1574892499301&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj9nuvfs4vmAhVlnuAKHSP0CDwQ_AUoAXoECA4QAw&biw=1920&bih=969#imgrc=3yxpJylyLEyyNM:
Found your leak…
Also sounds like you don’t have a vacuum controller.
I never used one with a rotovap
Just makes it easier to dial in recovery rate & avoid bumps without having to adjust bath temp.
Less babysitting needed for the system.
Especially on China rotos that leak all over the place.
HAHAHA i feel dumb lol
Contact your Roto MFG they will send a replacement asap, as they know those parts are faulty and break often.
So words of advice I would look over Summit Research’s SOPs on roto evap work. It helped me alot in understanding the movement of vapor inside the machine. You could be to aggressively decreasing vacuum. The boiling flask relies on having vapor pressure slowly flowing out which keeps a head-pressure on the solution. If there is no head pressure the solution can spontaneously erupt into a boil. Look up Superheating.
Cheers 
You shouldn’t.
That was all good & relevant information.
I couldn’t understand how a vac leak during SPD would send distillate to the cold trap. But I think I’ve got my head wrapped around it now.
However, I was just (4days ago?!?) regulating the vac on a rotovap (first time it had been used) at the feed valve, and it was pointed out to me that we were getting reflux but no condensing. Turns out the cold air in rush was condensing everything and dropping it back into the boiling flask.
@tweedledew then grabbed his version of a controlled leak (poor mans vac controller), closed the leak at the feed valve, and off to the races!!
I’m betting the OPs machine would leak until it (suddenly) didn’t, at which point it sealed and bumped.
Any reduction in vac, and it would leak again. Either dropping his solvent back into the boiling flash, or whipping it by the condenser so fast that it hit his pump.
@PrimO.Oil it’s possible @Xtractek might have one of those on hand (it’s usually the glass that breaks 
).
looking at the failure mode suggests it might have been over tightened…although contacting the manufacturer seems like a decent response too.
One thing I just noticed about your rotovap pic. Please use a strap and lab stand to support the condenser, and a clip between rf and condenser.
I learned most by copying others pics they posted up on here, and a simple rotovap vid on YouTube.
I don’t use a vac controller I have several ball valves on my vac lines to either limit vac or to burp with fresh air. I call that one the oh shit valve.
Don’t over grease your fitting. My understanding you’re putting cold eoth mixture inside the flask with the water bath temps pre warmed. You start pulling right after that?
This is the best way i found to make a Rotovap work efficiently with no bumping. You need a needle valve or someway to regulate your vacuum.
- Have the condenser temperature and bath warmed for 15-20 minutes. You want the temperatures to be stable inside the system. Keep the flask dipped in water bath empty for the 15-20 mins also. The flask is empty. 2. Fill flask and max out rotational speed after the 15-20. The vacuum may need to be applied so the apparatus doesn’t dismantle. Apply minimal. Control it at minimal. If your connections seems unsafe for max speed go to where you’re comfortable with it. This is the first part where you need to control your vacuum.
3.Next wait another 15 minutes maybe less depending on flask fill. the settings should be full/comfortable speed. No vacuum/minimal vacuum. The flask solution needs to be in equilibrium with the water bath temperature.
4. slowly vacuum down your system with a regulator. You won’t be able to go full vacuum at first but you will be able to find the sweet spot with regulating. Apply more periodically. It’s easier to control the roto with vacuum Bc it’s a rapidly occurring parameter but your other conditions need to be stable first. Tip: If bubbling happens to rapidly tighten the needle valve or slow down the roto speed. Both works. I like doing this Bc i don’t have to introduce outside air.
Solids in solution can also be a source of bumping…
I think a lot of folks are using the feed valve as a bleed valve.
The feed valve attaches to tubing and leads to the solution to be rotovap’d. You should have the flask spinning and up to speed and the water bath warm already and your vacuum applied before starting to feed in your solution. It will boil off as it hits. No bumping EVER.
And when you get really good you can trickle it in at just the right rate to walk away.
Bumping is caused by sudden drop in pressure, sudden creation of Nucleation points, etc.
if you feed it in when the boiling flask is already under vacuum and spinning and the water bath is up to temp you will never bump unless you overfeed it too fast.
With that being said wouldn’t I still have to break vacuum for my RF? I’ve seen people are using kegs or so but that’s a bit large for my operation
Yes. Just let the material in the BF dry out a little (not soupy) before you break vac to empty the RF. Then re pull the vac, and have the BF spinning (if you even stop it, no need) before you start feeding in more solution.