So I’m looking at buying a Welch 2034 for my 5L rotovap. I am currently using an across international easy vac 9 Cfm compact vac. I know they aren’t the best application but man does it ever pull. I’m looking into purchasing a Welch 2034 and pull my Ai from my roto. What I am wondering is if I am going to be disappointed with the performance of the Welch??.
I would hate to spend 3 times the money on something that takes twice the time.
im new to extracting so i dont know much but i have a welch 2047 and it works great with my 5l roto. i should have bought 2042 as that goes down to 29.85 vs 28.6 and i could use it for my oven but that model werent available at the time of purchase.
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That’s not your pumps fault. You’re likely seeing an inability to reach “full vac” or -29 because of the guage on your oven. You most likely dont need a “hard vacuum” on your oven anyways. You want to keep your Terps, not rip them out of your slabs. But that depends on what your end product goal is.
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my 2047 is rated down to 28.6hg, the 2042 is down to 29.86 , for vac ovens dont i want 29.5? im working with ethanol extracted material and trying to make some shatter. i tried a mini slab with a few grams and it never hardened up so i assumed it was my lack of 29.5 ability.
i am using a .9cf neocision oven from bvv. guage reads 28.6 after the 2047 reaches its potential, same as pumps specs online
You need to get the water out of your slabs if they are ethanol extracted. Try 200 proof, cryo temps, and maybe throw some mol seive (3a dessicant) in your filtered solution. Then filter one more time to get the dust out.
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i wondered if it was the water content, im using 96% everclear and extracting at -80c. i see best value has 200proof, ill put an order in and try again with your recommendations. thanks!
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Hey @Dab. The main benefit of using a Welch 2034 or ANY diaphragm pump is that they are chemical duty pumps and are less of a hazard than your oil pump. You are creating a fire hazard using the easy vac.
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I use a welch wob-l 2552, set at aprox -26.5hg for my 5L rotovap w/o any issues, 48c bath temp. Any higher vac and I get a small vapor from the pump.
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A good diaphragm pump isn’t really cheap but per @Demontrich suggested a wobl is a good cheap solution that can be found for about 100 bucks on eBay. I have 2 of them and haven’t damaged them yet with a roto and they gulp etoh every now and then. They aren’t chemical vapor pumps they’re designed for buchner filtering and vac ovens really but they work fine for a roto
say after rotovap i put the 96% ethanol extracted oil in my mini spd boiling flask and heated/stirred at 105f under 28hg vac. would that pull the 4% out and make it shatterable in an oven? nevermind the outlined box in chart, this is a water boiling temp under vacuum chart i downloaded.
The 2034 is a great pump but it is a little overkill for ethanol evaporation. The 2034 is used more for removing water at the end, but most people never get to that point because they leave enough ethanol in the extract to be removed easily from the flask when you’re done. I would suggest the Welch 2014B-01. It’s is about $500 less and would still work great for a 5L roto. Shoot us an email and if you’re part of the GLG we can throw in an extra discount. We should have a few in stock
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I’m transferring from roto to spd after tho. I don’t want any ethanol left whatsoever.
what does your 2522 pull at the vac gauge? I recently bought my second one and it pulls 500torr on my bullseye but says 20-25inHg on the pump gauge
haven’t been able to run my roto well because of this since it would only create vapor at 60C on the bath
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You’re always gonna have a little etoh left over from rotovap, and you’ll want it in there. This is all about saving you time.
If you want it ALL out you’re gonna be rotovapping for a very very long time. Then you’re going to be spending a lot of time heating your flasks up to move your extract to SPD.
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I’ve got 2x 2585 pumps both pull down around 27.5" to 28" on a mechanical dial guage
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