cnidocyte
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Gathering a distillation kit
I can't afford to buy a kit all at once so I'll just gather it piece by piece. Heres what I'm thinking:
- 1 liebig condenser (not sure what size to get)
- 1 still head
- 1 receiver
- 1 boiling flask to go with the still head
The standard taper joints part confuses me. I often hear people recommend 24/40 joints but when I search on ebay I see all sorts of joints but rarely
see 24/40. Seems like a pain in the ass only being able to buy glassware with the same standard taper as the rest of your glassware. Can you get
adaptors to change from one standard taper to the other?
Also I was wondering whether to get a receiver with a vacuum adaptor instead of a regular receiver since I can just block the vacuum inlet if I'm
doing simple distillations.
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DJF90
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24/40 is the standard taper in the US. Here in the UK, 24/29 ("B24") is a standard size. In the rest of europe, B29 glassware seems more common
(29/32). B14 (14/23) is another common size here.
You can indeed get adaptors between the sizes. What size joints you get will depend on what scale you wish to work on. You dont ever want to block the
vacuum outlet for any distillation, as heating a *closed* system is dangerous. Just leave it open, or attach some tubing to a washbottle for extra
piece of mind.
edit: heres one kind of adaptor - http://cgi.ebay.co.uk/Quickfit-expansion-adapter-B14-B24-Cat...
Heres a setup you might like: http://cgi.ebay.co.uk/Quickfit-glass-NINE-9-part-distillatio...
This might be more to your taste though, and is appropriate for moderate scale reactions! http://cgi.ebay.co.uk/Organic-Chemistry-Kit-27-BU-14-23-Glas...
[Edited on 11-12-2010 by DJF90]
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cnidocyte
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Thanks a lot for clearing that up. Standard tapers have been confusing me for years. I meant seal the vacuum inlet to use the adapter as a regular
receiving adapter. I didn't think that one through though, theres no need to seal the vacuum inlet in that case. With this in mind though, it seems
pointless buying a normal receiving adaptor when a vacuum adaptor does the same thing but can also be used for vacuum distillations.
Nice one for the links! Half the say I like that kit. Are 14/23 joints geared towards microscale though?
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DJF90
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Its pretty flexible for small scale work. B10 glassware is scaled towards microscale work. With B14, 15g of starting material is supposedly possible.
I've used such glassware back at school and it did well to produce a few grams of methyl salicylate, methyl 3-nitrobenzoate, and aspirin, amongst
other preps. I can't advise you any further unless you tell me roughly what preps you intend to do and on what scale.
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cnidocyte
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The main thing on my mind is distilling solvents so I can separate them and recycle them etc. Microscale wouldn't be of much use there. I'll have to
strike a compromise though cuz I don't want to get a huge setup that I'll only be able to use for solvents. Another thing on my mind is distilling off
aldehydes before they can be fully oxidised to carboxylic acids by K2MnO4 and for that kinda thing I don't need a very large setup. I'm aiming for
general purpose. May need to do microscale distillations, may need to do larger scale ones.
[Edited on 11-12-2010 by cnidocyte]
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DJF90
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I think thats the general case for most of us here really. The best compromise I can think of is getting two sets, one for each purpose (B14 for prep,
B24 for solvent recycling), but this will of course set you back some serious money.
On the plus side, you'd only need to buy the expensive accessories for the smaller kit - the larger kit would only need to be basic (distilling flask,
maybe a short vigreux, a stillhead, thermometer, condenser - a well positioned flask can collect the distillate, or you can get a reciever bend and
another flask to collect).
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cnidocyte
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There seems to be little or no information on the internet about standard taper joints. From wikipedia I found out that the US use their own system
and Europe uses the ISO system (ISO 383:1976). They're charging for the article on it
http://www.iso.org/iso/catalogue_detail.htm?csnumber=4364
Whats confusing me is what these letters mean. For example what if I came across B15 and wanted to know what size that code is for how would I do it?
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hkparker
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Where are you going to be buying from? I know expediglass is a great site, Ive used them for beakers and a few distillation adapter, good price, and
all borosilicate
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cnidocyte
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Preferably the UK. I'm guessing 2nd hand glassware on ebay is the cheapest way to get it. I'm having trouble with these automatic bidders though. As
soon as I bid, I get automatically outbidded and this keeps happening until the price has gone up over how much I'm willing to spend. I'm thinking of
going for that microscale kit that DJF90 linked since theres no bidding, I know exactly how much its gonna cost me.
[Edited on 17-12-2010 by cnidocyte]
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woelen
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I indeed strongly recommend to buy two sets. I have the 14 size and 29 size. The 14 size setup is equipped with 50 ml spherical flasks, a nice small
vigreux (30 cm) and a simple Liebig cooler and of course the vacuum allonge. I also have a 100 ml flask with this set.
The 29 setup is equipped with 250 ml and 500 ml spherical flasks, a 50 cm vigreux and a fairly long Liebig cooler. I have different flasks, also some
with two necks.
Try to find a 250 ml heating mantle. Such a mantle also perfectly heats a 100 ml flask. Even a 50 ml flask can be heated in that, but of course it is
quite inefficient, more heat is produced than is used by the distillation. But for home setups in microscale this is not a real issue.
I use the 500 ml as collector flask and then I use a 250 ml flask in the heating mantle. The 250 ml flask has a 29 neck and a 14 neck. Through the 14
neck I can drip in additional liquid to be distilled. In this way I can do continuous runs for 500 ml without the need to disassemble the setup during
the distillation.
Both sets together give me all flexibility I need and when I really want to distill 1 liter, then I just take the effort of partially disassembling
the setup by taking off the 500 ml collector flask, pouring its contents in a bottle and then reconnecting it again.
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cnidocyte
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Thats what I'm gonna do. Gonna go with B14 and B29 myself too. I ordered a B14 distillation kit but I'm gonna have to figure out how to get water into
the condenser before I can use it. Best approach in my case is probably a bucket of water and an aquarium pump.
[Edited on 18-12-2010 by cnidocyte]
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cnidocyte
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I bought a distillation kit but the guy only packed 1 condenser tube lol. I couldn't wait to test it out, to feed water into it, my plan is to use an
aquarium pump and a bucket of water but I don't have a pump yet so I tested it out in my kitchen but had no way to hook the tubing up to the tap so I
resorted to some Red Green show style improvising. I literally duct taped the tubing to the tap. Surprisingly it worked. My second tube didn't fit the
condenser nipple but some duct tape solved that problem too. Theres nothing you can't do with duct tape 
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Saerynide
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Like others pointed out, I definately recommend having 2 sets. Use the small one for trial runs and small scale and the large one for scale up and
solvent recovery.
I would recommend getting several sizes of flasks, with the larger ones having extra necks as you can always put stoppers in extra necks, but you cant
make extra holes in a flask And matching sep funnel and column too.
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Contrabasso
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Look for a heating mantle, then get the flask that fits it, then get the rest of the kit you need to match it. I found the proper controlled mantle
the most difficult thing to find. With solvents you need to be VERY careful if you heat with a flame, better a hot water bath.
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IrC
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Quote: Originally posted by cnidocyte  | Preferably the UK. I'm guessing 2nd hand glassware on ebay is the cheapest way to get it. I'm having trouble with these automatic bidders though. As
soon as I bid, I get automatically outbidded and this keeps happening until the price has gone up over how much I'm willing to spend. I'm thinking of
going for that microscale kit that DJF90 linked since theres no bidding, I know exactly how much its gonna cost me.
[Edited on 17-12-2010 by cnidocyte] |
http://quartzscientific.thomasnet.com/viewitems/standard-joi...
Helps to look at specs to comprehend what fits what.
http://en.wikipedia.org/wiki/Ground_glass_joint
http://www.ilpi.com/inorganic/glassware/joints.html
http://www.hsmartin.com/technical_info.html
Read all pdf's on this page (link above), useful info.
http://books.google.com/books?id=9mAEtf8zzXYC&pg=PA16&am...
Ebay: Seller puts up item with starting bid of say $5. Bid increment is say 50 cents (varies). Person comes in and bids $20. Bid is now $5. You bid
$10. Bid is now $10 plus 50 cents or $10.50. You bid $20. Bid is now $20 plus 50 cents or $20.50. It is as simple as that. When bidder places bid with
a max of $X dollars, then each time you bid more than actual bid the item will increase to next increment unless you bid more than the maximum amount
the other bidder placed first. If you bid with a max greater than the other bid ebay increments to the next increment above the other bidders max bid.
Easy to understand if you think about it. All you were saying is you keep bidding more than the current bid plus increment but less than the maximum
bid someone else already made.
Forgot to add you could focus only on 'buy it now' items if bidding is not your choice. I do when I see something I need and am not worried about
lucking out and getting it cheap. Happens seldom, there is a psychological part of ebay bidding where people will pay 50 times more than something is
worth merely because they cannot stand being outbid no matter how stupid the bidders are acting. Usually this screws the seller as they end up with
non paying bidders or NPB's.
[Edited on 12-25-2010 by IrC]
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DougTheMapper
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I'm surprised 19/22 hasn't been mentioned. It's a bit bigger than microscale with inexpensive flasks up to triple neck with a 1000mL capacity. DP
glassblowing on ebay sells a decent set and many brand-name suppliers sell stuff in 19/22.
Victor Grignard is a methylated spirit.
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Magpie
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When bidding on eBay this is my practice, FWIW.
1. Decide in your own mind the maximum you are willing to pay for the item.
2. Wait until shortly before the bid time is over, then place that maximum bid that you have already decided on.
Regardless of what you bid you will either lose the bid or you will win with a bid 50cents over the highest bid. It's that simple.
Now the term "shortly" is subjective. To skilled snipers it may be a matter of seconds. I'm not a skilled sniper, nor do I use such programs that
automatically snipe for you.
The single most important condition for a successful synthesis is good mixing - Nicodem
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