You could salvage a worm drive out of a skill saw or a pinion gear out of an angle grinder if you wanted to build your own rotovap
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the vacuum rotary union seems to be the difficult part to source
it’s also possible I just don’t know the right combination of words to make google happy
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That was the answer I got in the stainless rotovap thread.
The more you work with a rotovap, the easier it becomes. It is not uncommon for a rotovap to be fired up first thing in the morning, to run in the “background” all day long, and be the last tool to be turned off at the end of the day.
To some degree of approximation, the rotovap’s usage becomes an indicator of the chemist’s overall productivity.
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Yup, you can set it and forget it!
Once you find a rotary seal, or make a halfway decent one, the receiving flask (if it isn’t a ground joint) becomes the leaky seal. Little trick of the trade for larger rotovaps (5-50L), is to use the rotovap clamps and cut the lip off one side of a triclamp gasket with a razor blade, you can make a very solid metal to glass transition that holds vacuum overnight.
32/50 flat glass joints fit a 1.5" triclamp
40/60 flat glass joints fit a 2" triclamp
For my 50L rotovap, the 2" triclamp flange goes to a hose barb, to hose, to a sanitary keg. This relieves strain from the joint, so your vacuum stays at pressure without an active vacuum
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And set a timer and empty collection flask, refill rotavap flask, top off water bath.
Seldom did I go on lunch break without the rotavap in action.
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A really good trick is to use glycerin as a heat bath fluid. Its flashpoint is 160C so you can crank to 140 under vac to prep for distillation, it doesn’t evaporate very quickly, it’s easy to clean since its water soluble, and ok to inhale in small amounts. It’s 10x cheaper than silicone, safer than mineral oil to inhale, and lasts forever!
Edit: Don’t crank past 150C so you don’t dehydrate the glycerin and make acrolein and add a bit of water as a preventative measure; since you’re hydrating the glycerin (similar to sugar), the water won’t evaporate readily because it would need to dehydrate and boil the water.
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Do they state the ultimate vacuum this connection might be able to withstand before leaking?
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idk I just saw rotational sanitary fitting and got excited
That’s definitely something I’ve never seen before
Not invested in the stainless rotovap, but that’s a pretty sexy fitting
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Ya’ll need ferrofluid seals to accomplish your SS dream. A 10 or 20 liter flask is heavy when full so your going to need something stout. These are the ultimate in rotational mechanical seals.
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Looks useful, almost certainly not up for Rotovap duty, but I’ve added a couple to my Christmas list for install on the lids of our next set of fuges…we’ll see how the boss responds next week.
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