Or rather, only use the bellows from the cold trap to the pump.
My point of view is this: using lower quality vacuum oil doesnât âdamageâ anything, it just has higher content of oil that will boil at a higher pressure, leading to worse ultimate vacuum. Would using better oil help you pull deeper vacuum, absolutely. If you decide youâve made a bad choice or the oil youâre using isnât doing the trick, all youâve got to do is flush it a bunch with the good stuff. Itâs a messy pain but not the end of the world. Itâs not really any different treatment than what I do with a pump off eBay: take her apart, remove all the old oil, use scotch brite and barkeeperâs friend to gently remove the rust/burnt deposits, clean thoroughly with a quick flashing solvent (acetone works well), immediately bake the parts out for 2 hours at 120C in a vac oven, then get new oil into/on it ASAP.
If good oil isnât available to you, use the best you got. Keeping water, oil, and solvent out of your pump is much more important than keeping mediocre vacuum oil out. The water will actually acidify your oil and cause pitting, you should care more about that IMO
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So could OP use low quality vacuum oil as their SPD practice and end up with better vacuum pump oil as a bonus?!?
That which does not end up in the pump, is the bit that should go in the pump?
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Short Answer: No. Quality Pumps require Quality Oil.
Long Answer : You could use the cheap ass Robinair High Vacuum Oil BUT youâre also gonna need a day or two to flush your pump and itâs gonna make you question why you did it. You might also end up breaking something due to improper lubrication, so you probably shouldnât cause I hear flushing and rebuilding a pump sucks so much.
As a prime example, look at the Welch Duoseal 1400/1402 they both require special high vacuum oil but the outcome is perfect operation each and every time. No questioning humanity after having to do a major flushing and a possible rebuild, just clean operation.
But what @SidViscous also mentioned is important as well is making sure as much gunk as possible is stopped/lowered from hitting the pump oil will save you a bunch or at least prolong your oil.
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You arenât supposed to use acetone ok pump parts. Makes it delaminate at times. Iso is pretty useful.
In fact a bath of simple green or purple power tends to work the absolute best.
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Agreed on the detergent, although solvent is often usefully if too much âpot juiceâ makes it into the pump.
Out of curiosity, what delaminates? Every rotary vane Iâve ever taken apart has been entirely iron and cast aluminum on the inside other than maybe a bronze bushing or two. Not challenging (youâve rebuilt way more pumps than I have), just curious.
Hahaha Iâve never thought of distilling vacuum pump oil. Iâd be worried about the burnt bits left behind if the flask gets too hot but I suppose that could work. The volatile portion in even a really shitty pump oil would probably be too small to see so it might be tough to gauge when youâre done
The spining plastic parts inside.
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wtf does that mean ?? lol⌠I really donât understand what that means, sounds like some gypsy talk to me, like brad Pitt on snatch⌠hahaha
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Lol he means eliminate the bellows between the cold trap by using a male to male ground glass joint and a higher ring stand on the trap on the right. It will make a pretty big difference, that bellows is reheating any vapor that makes it past the first trap how you have it right now
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Iâve never seen any plastic parts inside a rotary vane pump but yeah, if your pump has any plastic in it definitely donât use acetone lol. I like it better than iso because it bakes out easier. The dissolving stuff better part is either a feature or a bug depending on what your pump is made of I guess
Is bellows the metal hose I got connecting the 2 traps together ? I can definitely do that, I do have a higher metal rod that I could use to make the second trap go higher and connect them directly with the PTFE KF25 adapters, should I go ahead and do that then ??
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Yes thatâs correct. You can clamp those KF joints right to each other and it should work fine, although generally ground glass joints seal a little better than PTFE so your best bet is to use a 24/40 male to male adapter. Downside with the glass is twofold: itâs a little less insulation than the PTFE and you donât own the piece lol. Something like this (ideally as short as possible):
Ok !!! Great, thanks for the link, ill use the PTFE adapters in the meantime, and im looking around in Mexican websites but can find any other oil other than the one I currently have, I will have to order it from the US but it takes a while to arrive, I will go ahead and do a test run with this oil I got in Mexico which in reality is pretty good or it has been really good so far with my cheap pump, still pulls vacuum like when it was new. I will do this unless you advise me not to lol.
Also do you have any suggestions on some other material other than CBD/THC oil I could distill to practice ?? im thinking about coconut oil, they sell unrefined coconut oil at my local Costco, im pretty sure I could fraction that into MCT oil, or maybe not MCT oil but im pretty sure I should be able to fraction it, its the only idea Iâve came up with so far to do my tests, but maybe thereâs some other material I could use to practice that im not thinking of, any ideas ??
I would just be prepared to clean your pump out pretty thoroughly when you switch to a different oil. Also, plan on doing A LOT of oil changes. Like, every 1-2 runs at least. I know people that change it after the heads.
As far as practice, you donât necessarily need to separate anything. Just moving it from one flask to the other is good practice. Anything that will stink if you get oxygen in (coconut oil does count) will work. Mostly youâre practicing not bumping, not overrunning the condenser, reading vacuum and temperature, and eliminating leaks. If you can get your system to run one decade (order of magnitude) above the blank off level (what the pump will pull with nothing but the gauge attached directly to the inlet) then youâre doing well. 2 decades is acceptable/normal, keep fixing leaks and working your traps until you can get below 3 at least. So for a pump that blanks off at 1 micron, 10 is the goal, 100 is acceptable, 1000 is youâre fucked
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ok ok ok⌠I feel you⌠just to clarity something to myself, when you say moving it from one flask to the other what is it that im moving ?? just some alcohol ?
Itâs a good idea to use some sort of oil, olive, canola etc. You want to run near the temperature that you would run your actual material because that is where your vac grease starts softening and leaks crop up. Itâll also help you get a feel for your mantel when youâre running hot. Youâll figure out why everyone insulates the fuck out of every millimeter of their head lol. Even just distilling alcohol is worthwhile practice although itâll cost more in vacuum oil because more will make it through your traps. Just remember, a tiny, tiny bit of oxygen can make your pretty second pass distillate smell like burnt ass hair
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I only use vac grease at the head to bf joint. The others I use distillate. A little trick I picked up on here a while back.
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You used distillate as vac grease ??? What do you guys think about MCT oil as vac grease ?? Thats what I have always used on my rotovap and it works pretty good
Yes
NO to mct
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