Considering a used centrifuge - need help to make a decision

[Anonymous Modernist 7891]

Hello folks,

I have been offered the chance to purchase a larger centrifuge at what could be a great price. I am trying to figure out whether this purchase is a great opportunity to get a high-end centrifuge for little cost, or if I am setting myself up for headaches.

The unit in question is a Beckman J2-21. It's an older model with analog dials and was previously used in a university lab. The asking price is a few hundred dollars, however the unit has no rotor. A JA-10 (6 x 500ml bottles) runs about $1500 used, while a JA-14 (6 x 250 ml bottles) runs about $500 used.

Then there is the matter of calibration. Beckman posts no product or information on their web site, and they do not handle random calls well. After much hoop-jumping I spoke to a Beckman service tech who quoted a minimum $680 for service - one hour of visual inspection plus one hour for travel. They are "not allowed" to give price quote for using instruments to measure balance nor for the actual adjustments - not even a rough estimate for a would-be buyer! I understand there are third party service providers; however Beckman is "not allowed" to tell you who these are. I know Beckman centrifuges are supposed to be good quality, but this is not a company that I would care to do business with.

Then there is the matter of safety. The warning in Modernist put my wife off completely; the recent forum post mentioning "catastrophic" and "possibly fatal" did nothing to help.

So bottom line: I'm intrigued at the prospect of spinning large quantities at 27,000 x g, but would first have to convince my wife that catastrophic destruction and possible death could be taken off the table with proper precautions. Second, if there were a way to lower the cost of the rotor. Third, if there were a lower cost option for service than Beckman, who are clearly not set up for helping a home cook and will charge exorbitant rates for the privilege.

Any thoughts or ideas (or rotors)? Any chance there's a centrifuge tech in Western WA who would like to partner up?

Much thanks,

--Scott

[Anonymous Modernist 7100]

If anyone knows anything about this please post because I am also curious and would like an answer regarding this.

[Judy Wilson]

The biggest thing to think about is what it was previously used for. You don't want anything that came in contact with bacteria or other pathogens--ever.

[Anonymous Modernist 9722]

If you are patient you can find cheap, used centrifuges in working condition, or nearly working condition. I bought a lot of 4 surplus centrifuges recently for $360, including a refrigerated Beckman Allegra R and 3 unrefrigerated Spinchron units. Both types have a 3-litre capacity, and can pull about 4,000g. They had been used in a VA hospital, then sat in storage for 6 years, which will bother some people. However, they can be disassembled and the parts autoclave sterilized (pressure canner) and chemically sterilized *very* thoroughly. It is a fair amount of work to do this, but it is not difficult. Also, I don't spin anything directly in the buckets anyway, I use brand new, sealed centrifuge bottles made to fit my rotor buckets. They were a little expensive at $130 for six bottles, but it's much more convenient. I reckon it's as safe as sterilized surgical equipment that is reused, as my sterilization process exceeded that used for surgical instruments and other reused medical equipment. Nobody is going to tell you to do this, including me, for obvious reasons. But I can tell you I haven't lost a wink of sleep over it -- I'm pretty confident nothing could survive my teardown + 10% bleach + autoclave cleaning of the equipment.

One of the 4 had been used as a parts donor; it's missing the motor and rotor. I'm keeping the refrigerated unit, and probably the parts unit and might consider selling the other two, but maybe not because everyone is squeamish about things and I am not accepting any liability.

Using it is fun as hell. I make clarified lime juice using the agar agar technique described on cookingissues.com, performing the speration in the centrifuge. Makes the best margaritas on the planet, and I haven't died from Ebola.

I just (today!) bought a Sorvall RC-5C for $42. That's not a typo. It is from a USDA lab that is being shut down, so no reason to believe it won't work. No idea what rotor it has yet, but this is the "washing machine" sized model they suggest in the MC books, capable of 51,000g, depending on the rotor installed. No need to screw around with agar agar to clarify lime juice, and it should squeeze out oil from crushed nuts. Or, it might be parted out, or not working, or have a rotor that only holds six 15ml test tubes. Oh well, it was $42. I can afford to buy a pig-in-a-poke for $42.

I know the bacteria thing is a big scare, and with good reason. But you have to remember these machines were made to do this work safely. Occasionally, test tubes break in a centrifuge and they need to be sterilized so they don't contaminate future samples. Hospital procedure involves sterilization after each use. The Sorvall manual has instructions for biological and radiological decontamination & sterilization because they need to be serviced and inspected occasionally, and this needs to be safely done. There are procedures to sterilize them, and they are effective.

That said, DON'T DO IT!!! You could kill yourself and everyone you know. You could start the next plague. You've been warned!

But I sure enjoy my margaritas!

Jim

PS: I also just bought two Rotavapor machines surplus for $146. Only one condenser, and it looks like they are missing the boiling/evaporating flasks, but I should be up and running for under $500. My rotor-stator homogenizer cost me $24. Don't know if it works yet. Just keep your eyes peeled, and be willing to do some fixing and cleaning. Or not. Probably better if you don't. :-)

[Anonymous Modernist 310]

Jim,

I would love to know where you're shopping! Me on my side I have the Beckman TJ-6 and I'm able to do most of the things with it. I did the same kind of cleaning regime and never put anything directly in contact with the equipment. The only thing I can add to your comment is to try to find something local because these are heavy equipment.

Good luck

Louis-Frederic Michaud

[Anonymous Modernist 9722]

Louis-Frederic,

I've bought most of my gear from government surplus auctions. Some of it worked perfectly, and some of it needed a little repair. All of it needs some cleaning. The rotor-stator homogenizer needed a replacement fuse holder (took about 5 minutes with a soldering iron) and the "aggregate" (the part that does the mixing) was stored improperly and had a seized bearing. Kinematica will replace the bearing and overhaul the aggregate for $150-200, so the whole thing will end up costing about $225, instead of $3000+. I got a heated water bath from the same auction for $5.

Most industrial equipment is made to be repaired rather than thrown away like consumer products, so if you have some patience you can usually get it going. You can also buy parts equipment and make one working machine from a couple dead ones.

eBay is also good if you're patient. I just bought a dry diaphragm vacuum pump for the rotavap for $110. I'm on the lookout for a used chiller for the condenser. Most of this stuff can be had for scrap value if you're patient. My inspiration is my engineering mentor who once bought a German gear hob for $15.

Jim

[Anonymous Modernist 19897]

Jim Campbell said

Louis-Frederic,

I've bought most of my gear from government surplus auctions. Some of it worked perfectly, and some of it needed a little repair. All of it needs some cleaning. The rotor-stator homogenizer needed a replacement fuse holder (took about 5 minutes with a soldering iron) and the "aggregate" (the part that does the mixing) was stored improperly and had a seized bearing. Kinematica will replace the bearing and overhaul the aggregate for $150-200, so the whole thing will end up costing about $225, instead of $3000+. I got a heated water bath from the same auction for $5.

Most industrial equipment is made to be repaired rather than thrown away like consumer products, so if you have some patience you can usually get it going. You can also buy parts equipment and make one working machine from a couple dead ones.

eBay is also good if you're patient. I just bought a dry diaphragm vacuum pump for the rotavap for $110. I'm on the lookout for a used chiller for the condenser. Most of this stuff can be had for scrap value if you're patient. My inspiration is my engineering mentor who once bought a German gear hob for $15.

Jim

Great post. I too am on the lookout for some good used lab gear. What are the specs one should view as necessary when considering a used centrifuge? Refrigeration? RPM range (I see units with low, med, high)? Capacity? Others? Honestly, don't know the first thing about them other than that they spin stuff really fast... Many thanks in advance for any used buying advice.

TJ

[Anonymous Modernist 310]

It depends what you want to do with your centrifuge. In my opinion the first thing you need to look is the capacity followed by the number of Gs. Refrigeration is a nice bonus but I managed to get around not having it.

The capacity is in liters or ml. The useful one are usually 3l. Don't forget that this capacity is splitted between many smaller containers. (Four and up)

Splitting what you want to spin in 500ml bottles is easy. Trying to work with 15ml tubes is much harder!

The higher G you can get the better. I manage to do mostly everything with a 3000G centrifuge but it's sometime longer or a little bit less clear. You cannot clarify lime juice without special techniques but you can do most of the things that you may want.

It's also possible to find a small cheap centrifuge if you want to experiement a bit but don't expect to serve a group...

http://www.cookingissues.com/2012/08/19/spin-cycle-homestyle-centrifuge/

Good luck!

Louis-Frederic

[Anonymous Modernist 19897]

Many thanks LF, appreciate the tips!

TJ