Sciencemadness Discussion Board - Ground Glass or No?

Ground Glass or No?

smaerd - 30-4-2010 at 13:48

As any other amateur experimenter I'm on a tight budget. Ideally I'd like to get a nice solid simple distillation set-up.

What I thought would be a simple task is becoming more and more daunting. Seems like one website will have a ground glass boiling flask, and then no ground glass still-head or liebig condenser. Then the next will have the condenser but not the adapter or the flasks.

I figure the vaccuum out-lit/adapter thing is pretty optional for these purposes, if that's an incorrect assumption please inform me

.

So I've got a few basic questions:
1. Is ground glass really important for simple distillation?What about for refluxing?

I'm not going to be working with anything too hazardous. I'm interested in essential oil steam distillation mostly(got a couple e-books on that from the library here

), but ideally, I'd like to be able to reflux with the set up as well.

2. Is there a list of reliable glass suppliers on here anywhere? Believe it or not I did use the (#*&#'ing search engine and came up pretty dry. I'd just hate to pay 35 bucks for a 250ml ground glass flask and have it break in transit or something(I'm a broke student I really can't have that).

3. This is going to sound stupid, but if I buy everything 24/40, it will all fit together right?

4. Is there any substitute for official lab-glass lubricant? Could I use mineral oil for most simple situations?

Thanks again guys

psychokinetic - 30-4-2010 at 14:04

1 - No I don't think so, but it is useful. If you don't have ground glass, you'll need lots of tubing and other connectors.

2 - Probably not. Your best bet as far as I know is to convince a wholesale company that your not making meth and buy off them (That's what I did).

3 - Yep. Well, as long as the numbers match up to each other.

4 - Not my domain, will leave for others.

JohnWW - 30-4-2010 at 18:34

Quote: Originally posted by smaerd

(cut)
4. Is there any substitute for official lab-glass lubricant? Could I use mineral oil for most simple situations?

For ordinary purposes, with not much heating of the connections, as a substitute for the highly viscous and expen$ive Apiezon stopcock grease (which is more suited to higher temperatures), you could use vaseline = petroleum jelly, which should be available from hardware stores or supermarkets. Automotive lube grease may be useable if a higher viscosity is required, being available from automobile accessories stores and possibly some better service stations, usually in cartridges for use in grease guns. There are also silicone and fluorocarbon greases that could be used in place of hydrocarbon-based greases, if highly reactive substances such as Cl2 that would react with hydrocarbons are to be handled in the vessels, but they would be much more expensive and restricted in outlets.

[Edited on 1-5-10 by JohnWW]

Don't pay those prices

SWilkin676 - 1-5-2010 at 03:41

Even new glass is cheaper from ebay - there are a number of stores that sell new glassware as well as used on ebay so you don't have to do the auction thing if you don't want to.

I sent you a link to a seller in china we have bought from, very good quality reasonable new stuff and ships quick. You can get a small distillation setup for about 100 bucks including shipping from him.

Somewhere on the board is a link to a book of recipes from the turn of the century, it has a recipe for glass joint lubricant as well as tips for getting them apart if they get stuck.

Also start saving bottles! We just set up a home lab and I thought my partner was nuts (he's the experienced chemist) for buying so many bottles and jars, but it seems like we never have enough, even with all the ones I save from household use or buy from thrift stores. Thrift stores and garage sales are good places to pick up coffee grinders and blenders - I can usually find a blender for under 10 bucks and coffee grinders less than 5. The little stuff will really add up.

Suzee

[Edited on 1-5-2010 by SWilkin676]

smaerd - 2-5-2010 at 13:21

Thank you all for the good information, and the suppliers.

Ordering glass made in china worries me, however the grade is appropriate and they seem to have purely positive feedback.

Thanks again everyone

bbartlog - 2-5-2010 at 17:05

I highly recommend glass over improvised tubing. For a while I distilled various substances using plastic tubing and rubber stoppers (tubing typically looped through a bucket of cold water). One day I got things a little too hot for the tubing, and the end that was sticking into the flask I was distilling from softened and melted itself shut. Pressure built up (I had gone into the next room for a few minutes) and eventually the stopper was blown out of the top of the flask along with a cloud of HCl and ethylene glycol vapors. Luckily this wasn't a fire hazard (I was using an open flame to heat the flask) but cleaning up all of the acid from every surface including the ceiling was a multi-hour operation. Just one example of how plastic and for that matter rubber can fail you.

leu - 2-5-2010 at 17:11

Buy a complete student's lab kit, it's cheaper than buy individual pieces :cool:

Chainhit222 - 3-5-2010 at 14:06

4. Is there any substitute for official lab-glass lubricant? Could I use mineral oil for most simple situations?

I recommend buying Dow corning vacuum grease. It is kind of expensive, but a tube will last you forever, and this guarantees you will not get any kind of contaminants, not to mention you can distill things like nitric and sulfuric acid without worrying.

And I highly recommend ground glass, its just so much quicker/easier/more reliable then using tubing and stoppers (not to mention Teflon stuff is expensive anyway). You will thank yourself in the long run for buying ground glass equipment. And I like unitedglasstech.com for glassware. Kind of expensive but they have quality stuff. you can also look at
http://expediglass.com/ and
http://kantu200scientificstore.ecrater.com/ but from what I have heard, they have lower quality glass, but I am planning on using it for stuff like beakers, watch glasses, burets, graduated cylinders, funnels (stuff that is not likely to experience strain from heavy heating/vacuum).

[Edited on 3-5-2010 by Chainhit222]

SWilkin676 - 6-5-2010 at 12:59

Quote: Originally posted by smaerd

Thank you all for the good information, and the suppliers.

Ordering glass made in china worries me, however the grade is appropriate and they seem to have purely positive feedback.

Thanks again everyone

I ordered some adapters (after I broke my first one!) from the vendor I recommended, they have survived my manhandling (you should see me trying to get the hose off the takeoff barb!) Also the guy screwed up and sent only one of each of the adapters so when I contacted him he sent the rest of my order along with 12 free keck clamps. My partner has ordered stuff from him and that is why I tried him.
Suzee

altech6983 - 16-6-2010 at 14:36

Yes ground glass all the way. You'll pay more (but your save in the long run) but you'll love how easy it is to work with. I know, I used to do rubber stoppers, a real PITA. Plus even if you don't think you will need ground glass now (I didn't think so either back when I bought the stuff just for rubber), you will probably move up to something that will need it later on.

I have to agree with Chainhit22, unitedglasstech.com is a great place for glassware. They are a bit on the expensive side but it is quality glass and they pack very well. I done several vacuum distillations with the 24/40 glassware and everything looks great. I'll let you know if I ever have any problem with the glass.

It cost me about 100 dollars for their glass but they were having a sale at the time. I bought though eBay from them. Here is the link to their eBay store. eBay: United Glass Tech Also buying a kit can be more expensive that piecing it together, you just get it faster (got mine all at once from United because I wanted it NOW

). I'm sure you could save money buy searching eBay over a few months and buying when you found good deals.

[Edited on 16-6-2010 by altech6983]

[Edited on 16-6-2010 by altech6983]

zed - 16-6-2010 at 23:43

In the past, I made many distillations using ordinary non-ground joint glassware.
It used to be available in large sizes at low cost. Really, really, low cost.

Boring the neoprene stoppers to assemble your equipment can be a pain in the ass,
but it is worth the effort.

Ground glass lab kits are also excellent, provided you are running small scale experiments. The largest flask is usually 500 Ml or so. Generally costs a few hundred bucks for a full set, but it's worth it.

For kits containing larger size vessels, I have occasionally seen ads on Lab X Auctions. Tempting ads....The price can be very right.

If you could bag a set-up like this, for the minimum bid plus shipping and packing (150.00 bucks or so). You would be well on your way to complete world domination. Yeah, I've seen better deals, but this doesn't seem too bad.

http://www.labx.com/v2/adsearch/detail3.cfm?adnumb=416067

[Edited on 17-6-2010 by zed]

[Edited on 17-6-2010 by zed]

[Edited on 17-6-2010 by zed]

Contrabasso - 17-6-2010 at 09:22

It really depends what you are reacting!

If you are involved with corrosives then a ground glass system with silicone grease on the joints will function and last well, corks and bungs maybe wouldn't survive there.

If you are working with non aggressive media then cheaper plain flasks will work well enough.

Keep looking on ebay and when you search something like "Lab Glass" or "Quickfit" then ALSO look at the sponsored links at the bottom of the listing. Sometimes you discover another lab glass broker that you were not aware of, perhaps one in your locality!

highpower48 - 25-10-2017 at 08:18

You can buy the Dow lubricant on eBay in 1/2 and 1 ounce sizes for not a lot $5 to $10 depending on size. It's repackaged but it's the real deal.

MrHomeScientist - 26-10-2017 at 07:24

I use silicone faucet grease from Home Depot, found with the sink repair supplies. It's in a little grey plastic case. Mine looks a bit different, but I think this is the same material: https://www.homedepot.com/p/PartsmasterPro-1-2-oz-Silicone-F...
Since you only use a tiny bit to grease joints, this 1/2 oz will probably last me my entire chemistry career!

JJay - 26-10-2017 at 08:02

The question of whether or not to use ground glass joints is kind of like the question of whether to put ice cream on pie. I mean, I guess if you don't have any ice cream, pie is still ok....