Teflon Sep. Funnel/Buret Stopcocks vs Glass

[Xenodius]

Hello all.

I am curious, What chemicals do I need to be wary of if I use a Teflon stopcock in a sep funnel versus a glass stopcock? And also, will a glass stopcock seal as well as a Teflon? I am looking at these eBay funnels:

Sep funnel, Glass Stopcock, 250ml (http://cgi.ebay.com/Glass-Separatory-Sep-Funnel-Glass-Stopcock-250ml-New_W0QQitemZ280005453170QQihZ018QQcategoryZ26408Q QtcZphotoQQcmdZViewItem)
Sep funnel, Teflon stopcock, 250ml (http://cgi.ebay.com/Glass-Separatory-Sep-Funnel-PTFE-Teflon-Stopcock-250-ml_W0QQitemZ270005633092QQihZ017QQcategoryZ26408QQ tcZphotoQQcmdZViewItem)

Don't know which size buret I will get but probably one that has the same stopcock as the sep. funnel, whichever I decide with your direction.



Any other suggestions or tips regarding initial purchases for a beginning pyrotechnic chemist would be very appreciated.

I will be purchasing all the glassware and tools for my soon-to-be lab soon, including burner, brushes, pipettes, buret(s), sep funnels, slim chance at a Sohxlet extractor, stands, wire heating gauze, wash bottles, test tubes/tongs, Grad. cylinders, beakers, maybe fleakers,(Love saying that) Florence and/or Erlenmeyer flasks, and slim chance at distillation apparati, if not then I will just get a retort, etc, etc...

Essentially everything for a basic (Economy :) ) lab. I plan on making Picric acid for sure, and probably HMTD since I have a pound of pure hexamine, maybe Acetone Peroxide, Nitroglycerin in the future, and I also have enough chems for 3kg of flash. (Keepin' it to like, 15g/trial :D)
(I have a separate building from my house to be entirely devoted to such a thing... only like... ~20'x15'x15' though. Its currently full of junk, and needs new siding, but will get a complete overhaul soon.)



Thankyou for any and all helpful replies. I did search for "stopcock" and "stopcocks" but didn't get anything relevant... Obscure question. :rolleyes:

[Bert]

You might want to browse Lab-X auctions. http://www.labx.com/v2/newad.cfm?catID=59&MainCatID=4

[nbk2000]

A Teflon sep funnel is impervious to anything you'll ever put in it, so don't worry. Avoid glass if you can afford Teflon.

[chemdude1999]

Teflon is pretty impervious to almost everything. I've ran hexanes, benzene and all the acids through teflon stopcocks. I'm not sure if acetone would degrade teflon, though. It might make it brittle.

I've used all glass before and ended up retrofitting everything to teflon. MUCH easier to work with. Simple to remove and clean and no grease. You can get just the stopcocks if needed to retrofit your older purchases. Research the chemicals if you are not sure though. Perchloric acid doesn't like anything, for example.

As for other purchases, if you can afford a chiller, get one. It can save your butt from runaway reactions. If not, get some varying sized tubs and beakers for ice baths. Check out ice makers. I good quality heat-plate/stirrer is good to have, too. Look for a cheap oven along with a freezer and fridge.

You probably really don't need burets, yet. But get A-class (B's aren't anymore accurate than Mohr pipettes). I'd recommend 10-50 mLs to start.

Condensation columns are nice to have and necessary for a lot of stuff. Examine the methods of distillation for the compound you what to work with. You can usually put something together with what you have.

I would also recommend not falling into the trap of buying expensive stuff because "real" labs use it. "Real" labs use it because it has to be certified and they need a chain back to the standards for legal reasons. For that reason, check out some of the Pyrex cookware. Excellent borosilicate glass for less than labware costs.

One last thing: Build a good quality bench to work on. Build your own, unless you can find a closing lab. Ring stands are necessary too. You can make your own if you have to.

[megalomania]

Glass stopcocks must have grease to work properly, and that grease can contaminate or react with whatever you run through it. That's why glass stopcocks have fallen into disuse.

The should be chemical compatibility charts for teflon available by searching on the Internet.

[Xenodius]

Everyone:
Okay, so teflon it is! Thankyou very much! :D I was erring on glass, not for cost reasons, but just because it sounded like it would be simpler/easier to use... >.> :o

chemdude1991:
Thankyou for the suggestions... an ice-maker is the one thing I really would like to get since my future lab is at least 120' from my house, and I don't like the idea of ferrying several ice-trays from our fridge.

As far as a bench, I am defiantly going to devote most of my lab to a long, sitting height bench and a comfy PC chair! :cool:

Only thing is I am deciding about what to top it with-- Granite would be ideal, obviously, but I am probably going to go with 18" tiles, which while the grout and stuff is stainable etc, 18" between grout makes it a pretty good working surface, great for recovering spills of solids, etc...

Lastly, my only regret about a hotplate/stirrer is the ~$300 price tag... Particularly when the innards are so exceedingly simple. I planned on making a DIY PC-fan stirrer, and I planned on using a old electric stovetop for a hotplate, but both together is another thing entirely.

Lastly, being 15 (gasp!) I don't have a whole ton of cash available, however I am very soon, long story short, going to make $3000-$3,500*, out of which I will take about 400 bucks to invest into my lab.)

(*For those who think I am lying, I am selling a '95 Ford Explorer that some tard sold for $500, only took $200 to get it up and runnin :D :D :D )

[chemdude1999]

Tiles would make a good all around surface. Stick with white or something light-colored and uniform. Keep your grout joints tight. The biggest part of laying tile on counters is the underlayment. Make sure you give it plenty of stiffness. They have mortar additives that you can replace the water you would normally use. I've used them and they are worth it. They give the tile some flex without breaking.

I would use either 4"x4" glass or porcelain tiles. Or, use larger 12 inch sealed ceramic tiles.

Also, you may want to dedicate some table sections to specific surfaces like steel plate for flame resistance and heavy work. If you can find asbestos that would be great. Look for old shingles. The only bad thing about tile, is that it won't give at all. So, if you dropped glassware it would shatter easily. Maybe keep some sink pads laying around just in case.

As for the hot-plate stirrer, look on Ebay. You can find them nice and cheap sometimes. Ice-makers aren't cheap either, so take a look in classifieds and things like that.

[Enkidu]

Lastly, my only regret about a hotplate/stirrer is the ~$300 price tag.

I purchased my Corning hotplate/stirrer on eBay for $120 IIRC. It heats up to 500C and has served me well. You could get one for much less (500C is a bit excessive ;)). On a side note, I noticed that you said you weren't planning on getting any distillation equipment. IMHO, this apparatus is very important unless you have access to pure reagents (e.g., nitric acid) or you are more interested in, say, pyrotechnics than HEs.

eBay is a valuable resource to keep forefront in your mind when your are assembling your laboratory. LabX is another valuable site; unfortunately, the cost of items auctioned/sold there is generally much more than a similar item being sold on eBay. LabX does have a wider, deeper selection of lab equipment, so you can buy just about anything that you want if you have the money.

[nbk2000]

We have members who have already been where you've yet to go. UTFSE would reveal solutions to your problems.

Build your own stirrer-heating mantle, using Brainfevers tutorial here:

http://www.geocities.com/brainfevert/heatstir.html

And don't use tile or anything else porous, shatterable, or with cracks/crevices/joints. Oh, and flammable is bad too.

A sheet of stainless-steel is ideal in every respect.

[megalomania]

A lab hotplate *should* be designed to be compatible with a magnetic stirrer, meaning you can stick the hotplate on top of the stirrer and get the best of both. I have several hotplates (the hemispherical ones for RB flasks), but alas only the one mag stirrer, no combo units, and they work fine together.

I was fortunate enough to obtain several lab tables from a local school that closed down. Those tables are the heavy duty ones with the special chemical resistant surface. The cost a fortune new, free is more in line with my price range.

I know I have seen in an old book about building your own lab how to chemically treat wood to make a lab benchtop. Basicially you want something to resist chemical corrosion, which makes plain wood and any metal a no no. Your best bet would be a slate top if you can get it, or the special treated table tops made for labs. Alas wood should be a far more expedient choice as a "topper" that can be disposed of periodically (think plywood).

Without a treated surface you must maintain impeccable cleaning standards: clean up all spills asap.

[Xenodius]

Chemdude/Enkidu:
I appreciate the input-- Particularly eBay Hotplate/stirrers (DUH!) and also on that mortar adhesive additive.

nbk:
I did search-- but searching again more thoroughly, no excuse for missing some of the articles. I apologize, and simultaneously thankyou for the link to Brainfevers site-- although I cant comment on the content yet since its blocked. (Internet 'security' software)

Megalomania: I didn't realize that a magnetic stirrer could stir through a hotplate... I am looking at a $28 hotplate on lab-stuff.com, but I think I will watch eBay very carefully for neglected auctions, try to get a combo for a reasonable price.

Thankyou all for your input, I feel perfectly straightened out and set on a road for explosions. I don't think I will need to bother anyone with questions for a very long time.

Haha, and my friends were mesmerized for an hour when I threw Cu(II)Cl on a bonfire... cant wait to make some primary explosives, that would be an absolute racket. :cool: :D :rolleyes:

[Chris The Great]

He means a heating mantle, not a traditional hotplate, if I understand correctly.

Buy the hotplate stirrer, it is something I really wish I had. It just makes everything so much easier! And get the distillation setup, to make nitric acid. Except for some beakers (simply for their excellent thermal durability) you can really improvise the rest if you want too.

Although I have done quite a lot of work in the past with just jam jars and a little ingenuity... it really does make everything so much easier when you have purchased the proper tools for the job. I was so happy when I first used my separatory funnel to make nitro, it was so quick and easy compared to trying to carefully siphon off layers or using syringes or pipettes etc. It wasn't NEEDED but it made the separation and washing so much easier.

One thing I thought I would suggest for the lab bench, as I will soon be trying it myself, is using a plastic mat used to protect carpets. Being cheap, soft and easily cleaned, I think that they might be a great cover. Plus, if it gets ruined, it is easily replaced with a new one. Right now I am using newspaper which is working decently enough, but a plastic cover that can be easily cleaned and removed would seemingly be ideal.

Glassware won't break that easily on it either, since they have lots of stubs on the bottom to grip the carpet- these would seem like they would be perfect to help reduce impact of dropped glassware. I'll give it a try hopefully next weekend (lab cleaning week) and see if it works as well as I hope it does. Or just works I guess... better than what I have right now.