| Pages:
1
..
16
17
18
19
20 |
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
Deschem has served me great, too. They have improved their shipping recently, and shipments have been coming over pretty much consistently in 2-3
weeks, packed to withstand intercontinental damage.
I just received another order from them, nothing fancy, just a stock of some spare parts and an extra jack. Also I bought a short vigreux head to
allow for better separation compared to straight distillation without greatly impeding flowrate.
The 50mL glass syringe is also fancy.
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
300mm Allihn condeser, 100mm thermo well, couple flasks. From deschem.
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
|
|
|
karlos³
International Hazard
Posts: 1520
Registered: 10-1-2011
Location: yes!
Member Is Offline
Mood: oxazolidinic 8)
|
|
I have to say, deschem really improved their shipping times!
I had to re-order a few thermometers and simply bought twice as much... 7 working days only!
Impressive 
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
Fastest for me has been 7 days too, exceptional. Usually it takes 2-3 weeks, or around 20 days.
At least for some parcels they have started using forwarding parcel services, which means faster shipping and they take care of importing. I would
call that a great service.
100% of my equipment bought from them has been flawless. One shipment was smashed on the way, but it was not their fault - the parcel was just plain
crushed with something HEAVY, and I mean it - I can stand on their parcels with no stress, they are so rigid so I believe something major fell on it.
It was resolved in a very convenient manner.
|
|
|
Phosphor-ing
Hazard to Others
Posts: 246
Registered: 31-5-2006
Location: Deep South, USA
Member Is Offline
Mood: Inquisitive
|
|
I recently received my 4th or 5th order from Dr.Bob. Hot plate/stirrer, condenser, long vigreux column and various flasks in 29/42. Love ordering from
him. He Includes free stuff and packs it to survive whatever the shippers can dish out.
"The nine most terrifying words in the English language are: 'I'm from the government and I'm here to help.'" -Ronald Reagan
|
|
|
earpain
Hazard to Others
Posts: 102
Registered: 11-9-2019
Member Is Offline
|
|
Quote: Originally posted by earpain  | So you guys probably saw these kits flood the Chinese shill vendors who may or may not have warehouses right next to you(but it always says they do).
Looks like the 'guild' has raised the price. My order went like this:
posted as ~$60 or best offer. Hmmmm, normally for $60USD i might get two of those items at best. So i went through his history for this item, and
almost all the orders said "accepted offer". So brazenly, I offered $7 below asking. I said it was a great deal but i'm very poor. Response was
warm and friendly. And discount #1: he countered at $3.00 below asking price. I said hell yes.
So then of course i get a tracking number that for over a week is stuck at "waiting for package to arrive at facility/" I know what this means. I
sent him a message saying I thought that was a bit sleazy, since the marketing included a map of my country with regions showing either 1, 2, or 3
days! I was in the 2 day zone.
BAM: Instant Discount #2 - $10 refunded to my PayPal right away.
I kind of have to now confess that this is the best deal ever for glassware. It is branded, however the company's name is in Chinese characters. But
the Glassware is up to par with Deschem if not better.
The cut out foam is now the 'case' for safe storage.
The leibig and the vigereux column are so much longer in real life than it looks like in the picture. This really makes a huge difference for
distillations.
The addition funnel has some new design for its stopcock that I cannot explain. But somehow it allows both for perfect drip...drip.. control, and yet
if a bunch of salt or gunk clog up the bottom, i can turn it and it all plops out. It's the perfect separation stopcock.
Yes I have enough 3-way adapters now to last me several life times.
Lastly: I was SURE i had received the wrong keck clamps at first, they looked like 19/x. Then I thought 'hmmm', with some extra thumb muscle, it snaps
on, and it SNAPS on any joint. Like these keck clamps will hold big flasks and condensors while they patiently wait for me to find my support
hardware(do not do that ever, so stupid)
(the thermometer went up to 100C and broke the first day. Nothing else has broken at all)
|
Update: too good to be true is just that. However, this remains to be a great deal. It almost feels as though the worst glassware was mixed in with
the best, for obfuscation.
Edited image is self-explanatory.
worth a mention:
* Addition funnel works, though 24/40 joint is gone
Condenser and Vigreux column seem to be indestructible(famous last words)
Crossed out glass stoppers represent proportion of the total. As there were stoppers lined around the entire package.
I treat my glassware a bit rough, but I prefer that to a 'walking on egg shells approach'.
My apologies for unintentionally misleading
|
|
|
Fluorite
Hazard to Others
Posts: 138
Registered: 26-12-2018
Location: United Arab Emirates
Member Is Offline
|
|
I'm excited because I finally bought a sep funnel, 1L Erlenmeyer flask and beaker (with some tiny air bubbles in the glass but whatever) and 500ml
reagent bottle with PP lid
Any tips for using these without breaking them?
Should I boil water in a glass to get it hot before boiling sulfuric acid in it?
Is it better to heat the glass as slow as possible to prevent thermal shocks?
And is paraffin wax bath good for boiling sulfuric acid?
Oh and the air bubbles! Should I be worried?
 
|
|
|
Oxy
Hazard to Others
Posts: 140
Registered: 1-12-2020
Member Is Offline
|
|
If the glassware is made of borosilicate glass you don't need to pre-heat it. It can withstand a significant thermal shock, so it will definitely
survive some gentle heating. Do it slowly however and remember that boiling-hot sulphuric acid is known of violent bumping, which can lead to some
damage to the glass and things nearby.
|
|
|
earpain
Hazard to Others
Posts: 102
Registered: 11-9-2019
Member Is Offline
|
|
yup. what's the brand? Esco labs? I never had any of there glassware but they seem very reputable.
Beakers, except maybe huge ones, are probably the hardest to break. Along with Erlenmeyers/conicals.
Thermal shock is nowhere near the top of my list of causes of broken glassware. It's definitely much more likely to occur upon cooling from a heated
state, than from sudden heating. Reason being, since generally one heats the vessel from the outside, the outer portion of the glass wall will expand
first, and there's nothing constricting it from expansion. However when cooling down, the innermost part of the glass wall will be in a hot, still
expanding state. Dropping it in an ice bath will first cool the outer side, constricting the not-yet-cooled inside, and if the Delta(T) is severe
enough, it has no choice but to crack.
Definitely don't heat up your beaker you intend to put H2SO4 in with water first. Better to heat it up with H2SO4 in it, ya know?
The mid 300's C, the BP of H2SO4, is childs play compared to the temperatures I deal with when I manipulate boro glass with a torch.
But yeah, i'm still watching that thing like a hawk anytime I'm concentrating H2SO4, and have some sort of plan B in mind if the worst happens.
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
160C is the gradient for boro.
Although, when I cool down reactions that are hot, like 150C, I first use hot water, 50-70C, to bring it below 100, and then use cold water to
finalize it to ntp.
I don't know if anyone has yet tested it, but I suggested using air pump and bleeder tube to agitate sulfuric acid to prevent bumping. Also, I would
use flask that is worth losing, like cheap 2L rbf, and it also needs a lot of heat, so it likely must be heated directly with propane gas. I've
noticed that for effective boiling, thermal gradient must be over 20C with water-CaCl2 bath, and 50C with oil bath.
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Estate sale!
 
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
|
|
|
earpain
Hazard to Others
Posts: 102
Registered: 11-9-2019
Member Is Offline
|
|
| Quote: Originally posted by Fyndium | 160C is the gradient for boro.
Although, when I cool down reactions that are hot, like 150C, I first use hot water, 50-70C, to bring it below 100, and then use cold water to
finalize it to ntp.
I don't know if anyone has yet tested it, but I suggested using air pump and bleeder tube to agitate sulfuric acid to prevent bumping. Also, I would
use flask that is worth losing, like cheap 2L rbf, and it also needs a lot of heat, so it likely must be heated directly with propane gas. I've
noticed that for effective boiling, thermal gradient must be over 20C with water-CaCl2 bath, and 50C with oil bath. |
Although almost all borosilicate scientific glassware proudly boasts of the 3.3 thermal expansion coefficient, there are still different types of
boro, some more heat conductive, some more insulating. Some have a chemical treatment done onto the surface as a final step to make the glass
hydrophobic - I've noticed this effect in some of the very high end brands.
H2SO4 - hmm, I see your logic there. But on the flipside, I might say that such times call for the best, most durable of my glasswares.
Although I'll admit it's been years since I've had oxy/propane and worked wall thickness in the scale of most scientific devices, I routinely work
test tubes, thinner parts of broken devices etc. over open atmospheric propane.
Unless I'm aiming for a complex spot, I've never had an issue with going directly to open flame. Not with boro.
Having the container filled with H2SO4 should even further fortify the thermal structural integrity. What I don't do is put a beaker on metal grill
over open flame, such as on my stove. I put a frying pan on the metal grill parts, beaker on the frying pan.
One of my longest lasting and most abused, 1L erlenmeyers was routinely heated that way for like a year. And then one day it cracked, from sudden
heat.
So my observation for thermal gradient, is that it depends on the vessel, and the glass. If I have a specific pan with sand in it I plan to reuse,
and a specific flask, first time I bring something with a high BP to a boil, with two thermometers.
A tiny 50ml RBF will have a far more dramatic temp difference, as well as thermal latency effect, as compared to a 2L RBF.
|
|
|
violet sin
International Hazard
Posts: 1480
Registered: 2-9-2012
Location: Daydreaming of uraninite...
Member Is Offline
Mood: Good
|
|
I feel this counts, or close enough. I ordered a few Geiger–Müller tubes from GSTube.com and they came the other day. Total 2 months in shipping
lol, Mar 2 - May 6. But intact they were box was in great shape.
 
|
|
|
MadHatter
International Hazard
Posts: 1339
Registered: 9-7-2004
Location: Maine
Member Is Offline
Mood: Enjoying retirement
|
|
High Efficiency Condenser
Recent acquisition: Davies double jacket(300 mm) condenser
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
|
|
|
SWIM
National Hazard
Posts: 970
Registered: 3-9-2017
Member Is Offline
|
|
An "Ace Glass #7 Jacketed column" according to Ebay.
Actually a quartz immersion well.
The brown stains in the water jacket make me think the last owner though it was a cold trap and used it for vacuum distillations.
It does have some cheesy hose fitting jammed in the ace thread inlet.
Its jammed in the real hard, but I figure if a wrench won't loosen it I can just burn it out with a propane torch, and then dip the immersion well in
a bathtub to cool it off.
Thermal gradients be damned!
[Edited on 13-11-2021 by SWIM]
|
|
|
SWIM
National Hazard
Posts: 970
Registered: 3-9-2017
Member Is Offline
|
|
I'd sure like to find out what the story is with Vineland, New Jersey.
It's the one city name I see most often associated with jointed glassware.
Ace Glass, Wilmad, and at least three other companies.
Now four counting the stuff you just bought.
If you heave a brick out a window in Vineland you must have a pretty good chance of hitting a glassblower with it.
Edit: LG glass and Bellco are there too.
Edit: @ S,C, Wack, thanks for the info.
[Edited on 13-11-2021 by SWIM]
[Edited on 13-11-2021 by SWIM]
[Edited on 14-11-2021 by SWIM]
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
There's a school there for one thing. It wasn't all that expensive either when I looked a long time ago and should have went but didn't because where
was I going to live or find a job. Can't just start a glass operation in Topeka. IIRC glass companies originally started there because of a nearby
source of particularly good sand.
|
|
|
Organikum
resurrected
Posts: 2337
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: frustrated
|
|
What I always wanted
I finally fulfilled my long harbored dream and got me this:
The reactor. So tired of cleaning big flasks through tiny openings, no proper stirrer can be used for everything has to get through a small hole, I
believe all flasks of 1000ml or larger should be outlawed and replaced by something like this.
Also this is much simpler to produce (at least the flasks, maybe not the heads) they are prohibitively expensive. But I was luck and found the
probably best second hand lab equipment dealer in Germany ("secondlab" on Ebay Kleinanzeigen, nice guy, is aktiv on Illumina) and so I went for it.
Sadly he had only the 4 liter reactor flask and I got a 500 ml for a decent price elsewhere, but now I am searching for 1 liter and 2 liter and cannot
find anything for a reasonable price. I would need the kind with the groove for an O-ring so any possible. And it is DN100.
The secondlab is really gold, the high performance condenser in the picture was about 30 € and I got an Anschütz-Thiele for 25 €, I seriously
could not believe it. And it is all in decent shape, the important stuff is mostly Schott, some Jena some Mainz but this is all good IMHO, personally
I prefer the thinner Jena glas over the very thick new kind as the heat transfer is so much better with thinner glass.
Anyways if somebody can help me finding those reactor flasks DN100, 1000 ml and 2000 ml that would be great!
thx
ORG
[Edited on 28-11-2021 by Organikum]
|
|
|
SWIM
National Hazard
Posts: 970
Registered: 3-9-2017
Member Is Offline
|
|
Is that little heating bath okay?
A lot of manufacturers of similar reaction vessels in the USA specify low watt-density heating (like mantles) to avoid cracking the thicker glass.
Maybe I'm over-cautious, but if I don't have a mantle the right size I use a heat bath that covers a lot more of the vessel's body.
[Edited on 28-11-2021 by SWIM]
|
|
|
Herr Haber
International Hazard
Posts: 1236
Registered: 29-1-2016
Member Is Offline
Mood: No Mood
|
|
A cousin living in Mainz (Germany) sent me 45 Duran test tubes for my 45th birthday.
Pretty cool and I like the humor.
Mainz is the headquarters for Schott GMBH.
Weirdest of all, every one of them arrived intact. I didnt think that was possible when sending test tubes.
The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
|
|
|
Organikum
resurrected
Posts: 2337
Registered: 12-10-2002
Location: Europe
Member Is Offline
Mood: frustrated
|
|
| Quote: Originally posted by SWIM | Is that little heating bath okay?
A lot of manufacturers of similar reaction vessels in the USA specify low watt-density heating (like mantles) to avoid cracking the thicker glass.
Maybe I'm over-cautious, but if I don't have a mantle the right size I use a heat bath that covers a lot more of the vessel's body.
[Edited on 28-11-2021 by SWIM] |
Oh, there is no heating bath at all, what you see is a ring to hold the vessel up. This was just a first test setup anyways, virtually everything is
changed now, I will soon post a picture of it in its last iteration.
But I still do not use a liquid bath, I am with the good old "hot air bath". The vessel never touches the hotplate which can get get glowing red hot
so necessary (PID controlled), a aluminium foil "tent" keeps the hot air near to the flask, most heat transfer is by infrared radiation though.
This keeps the thermal masses low and is very gentle on the glassware. No hot liquids involved.
/ORG
|
|
|
TinyPlanets
Harmless
Posts: 3
Registered: 7-5-2022
Member Is Offline
|
|
Little vacuum sublimator and some new PTFE sleeves.
I loathe vacuum grease and these new sleeves are a dream.
My older PTFE (made in 2000) sleeves are thinner, unribbed and have a habit of getting stuck permanently on joints.. have to rip them off with pliers
(damaging them in the process) when they're stuck.
Surprised there is so little information on PTFE joint sleeves available online.. would be nice to read a usage guide or some hacks.
|
|
|
flaminglasrswrd
Harmless
Posts: 9
Registered: 17-9-2019
Member Is Offline
|
|
Dumpster dive finds!
The only thing I paid was a few cuts from some broken glass. Well, that and all of the time invested in checking the dumpster each week for the last
few years.
The results:
Boxes and boxes of glassware and equipment. Several 2 and 3 liter RBFs, a 3L sep funnel, 4 Friedrichs condensers, two Edwards RV3 vacuum pumps, one
Welch 8907 pump, two Buchi r114 rotavaps with water baths, a thermo 6255 vacuum oven, a Fluke 412B HV PS, a thermo CL2 centrifuge, a Lytron mcs20g
cooler, and a thermo electron 2870 shaking water bath, two cases of TLC plates, and a couple of variable reflux distillation heads.
Lots of other condensers, graduated cylinders, addition funnels, flasks, assorted ground glass adapters, gas valves, some quartz stuff, and more.
All of the equipment seems to work and I tossed all of the broken glassware already. Some things have minor damage but they work all the same.
I had to make several trips back to the dumpster to get everything. Like I said in my other post, apparently one of the chem professors retired and
they cleaned out his lab. Lucky me!
I'm keeping most of it, but if something catches your fancy lmk and maybe we can work out a deal.
      
|
|
|
Rainwater
National Hazard
Posts: 919
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
2 pressure equalized addition funnel, please. Sweet score btw
"You can't do that" - challenge accepted
|
|
|
B(a)P
International Hazard
Posts: 1139
Registered: 29-9-2019
Member Is Offline
Mood: Festive
|
|
Just got myself a secondhand IKA Combimag-RET hotplate stirrer, to replace my wounded cheapo 79-1 hotplate stirrer.
Can't wait to put it to use, sadly it is staying in its box as we are in the process of moving house.
|
|
|
| Pages:
1
..
16
17
18
19
20 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
