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[*] posted on 24-8-2010 at 23:42
Anhydrous AlCl3 attempt


After seeing chainhit's thread on AlCl3 with a barbeque I thought I'd give it a try.
I used a Ca(OCl)2/HCl chlorine generator through a CaCl2 drying tube then H2SO4 to suck the last of the moisture out, running through 25mm copper pipe in the BBQ with Al foil in it.
Instead of a condenser I attached another length of copper pipe with a damp rag sitting on it, this way it wouldn't clog up as easily and could easily be disconnected and have a cork rammed through to collect the AlCl3.
Here is the setup:


The inlet for the chlorine:


The 'condenser' and makeshift drying tube:


I thought everything was running smoothly until I realized some fumes leaking out of the BBQ. I noticed the chlorine had been reacting with the copper and had eaten a hole through the pipe, I shut off the heat and turned off the chlorine generator.
The pipe was thin enough to tear apart at the hole, it was full of anhydrous copper chloride and a bit of aluminium chloride.


Copper chloride crystals:


I rammed the rod down to clean the foil from the tube. It looks like the copper chloride had been subliming then traveling down the tube to the unreacted Al and reacting to form AlCl3 and coat the foil in copper.


The CuCl in water:


Here is the only AlCl3 I could collect from the condenser:


Does anyone have any ideas as to how I could stop the copper reacting? Was it just too hot for it?
I'm going to buy some more copper pipe and give this another shot, I've left everything set up still.


[Edited on 25-8-2010 by spong]
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[*] posted on 25-8-2010 at 03:29


I thought I mentioned in my thread to not use Cl2 gas, as it seems to react with everything.

Stick to HCl made with H2SO4 + NaCl or CaCl2, it leaves the pipe alone.


I gotta say though, when I ran Cl2 through mine, it never looked like it was gonna eat through the pipe!

And are you using a carrier gas? I found it pretty important to push everything through the pipe using argon. Do not pack the Al too tight or you will get jams. The pipe I used was 1 inch ID.
And TBH when you make HCl using a salt/acid generator, it seems pretty unnecessary to dry the gas, I put a little tube of color changing desiccant (cobalt chloride impregnated on some kind of zeolite or some shit, idk what it is) and it barely changed color.

The best procedure is to turn on the carrier gas after the aluminum is hot enough to be in danger of oxidizing (I use 5psi because it seems to be the lowest my regulator can go, it seems a bit excessive), let it get fully hot then turn on the generator and run it all the way. I set it up so the carrier gas inlet was nearly on the bottom of the gas generating vessel, so it was sure to push all the HCl out.

BTW, I tried using a steel fence post for this instead of copper pipe, and it worked very poorly.

Be sure to leave a container over the end of your condenser like this:
http://img826.imageshack.us/img826/5139/jar.png

It really seems to catch alot more AlCl3 if the fumes have to collide with the jar bottom and change direction, or so it seems. I don't know why, but I swear, it collected the AlCl3 so much more efficiently.

I plan on doing more research on this, only problem is that it fumes so bad and my neighbors are pretty close, so I gotta wait for a nice cold moonless cloudy night to do more research, and I have been sidetracked by other things.

I am kinda curious about using a fluorescent light bulb tube instead of a copper pipe. If it could survive the BBQ, one could use chlorine gas (which I must admit seems to react more readily)..... I think I read that UV light emitting flourescent tubes are actually made out of quartz glass, they could prove to be a good OTC resource.

According to Wikipedia, regular fluorescent tubes are made of borosilicate glass... which has a softening point of 800c.... I think I'm gonna crack one of those open today, clean it and throw it on the bbq to see what happens.

And I have a question, is aluminum metal completely resistant to the action of chlorine gas at room temperature? What would happen if one had a flask filled with shredded Al foil and some chlorine gas, would it not eventually react with the chlorine, over the period of several days?

[Edited on 25-8-2010 by Chainhit222]




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[*] posted on 25-8-2010 at 05:27


I was a bit worried about the chlorine but I didn't expect that, I was a more afraid of the hydrogen if I'd been using HCl, if I'd had a hole like in that one I probably wouldn't have a barbeque/eyebrows anymore :/
I wasn't using a carrier gas, I should probably get a little bottle of agron or nitrogen, how much do they usually cost? Perhaps I could just use air from my aquarium pump or something provided the Al won't oxidize. If the gas is expensive and air won't work I'll just make a CO2 generator.
Yeah I was thinking about flourescent tubes today but I didn't have any that would reach all the way through the barbecue, it would be much easier to see what's going on, you could probably melt both the ends and make them fit 24/40 fittings as well.
There's definitely some potential to this method, with the big clump of copper chloride I accidentally made, it shouldn't be hard to produce loads of AlCl3 with the correct technique.

You'd think it would have to react a little at room temperature, I've got a thin layer of what I think is hydrated aluminium chloride and bromide all over anything aluminium in the shed along with other salts on different metals that were exposed from the shed being filled with HCl or Br2.

[Edited on 25-8-2010 by spong]
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[*] posted on 25-8-2010 at 07:24


You don't need to make 24/40 fittings. All you need is container of aluminum foil. Cut a really long strip of Al foil (a few feet at least) and carefully wrap it around the male end of a 24/40 connection to increase its diameter, then you can make a fitting joint. Even if its loose, the bulk of the AlCl3 will flow through the large opening. The aluminum foil joints wont get eaten too much, as they are not directly in the flames. Its kind of a dirty solution but it works well.

I seriously doubt you would get a explosion, even if you were pumping acetylene into the bbq. There is not much oxygen there (the propane is burning there anyway).

btw, don't use a 24/40 liebig condenser, it is too narrow, and it will clog up with alcl3 rather quickly. I had to poke at it with a sharpened steel wire and shit while it was on the bbq because it kept clogging, it was not pleasant (had to wear gas mask). You want the internal condenser diameter to be at least as big if not bigger then the AlCl3 "tube furnace".


Im not really sure what would work well. Perhaps this:
http://img201.imageshack.us/img201/9705/76070303.png

Same design as yours, but the condenser is removable. You could then take a long steel pipe cleaner (looks like a glassware brush, but it has steel bristles) and push it through the condenser while it is over your container, in order to scrape the walls.

As for the argon/nitrogen tanks, their kinda expensive. But consider that once you buy a one, it will last you a hell of a long time, and refills are not that expensive. A decent bit of reactions need a inert gas. I saw small tanks being sold in the fisher price store for like 50$ i think, I have a big aluminum welding tank that costs like 200-300$.

Btw, you can try purifying your AlCl3 by doing a vacuum sublimation on it. AlCl3 has a sublimes at a lower temp then FeCl3. It is kind of a pain in the ass though.

[Edited on 25-8-2010 by Chainhit222]




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[*] posted on 25-8-2010 at 07:33


Cool experiment. You should distinguish between CuCl and CuCl2 when describing and evaluating your results - the brown stuff and the blue solution are presumably CuCl2, but it's entirely possible you also ended up with some CuCl (which BTW is not soluble in water). In particular it would be nice to rule out the possibility that the white stuff you ended up with is CuCl rather than AlCl3.
I don't think you can stop copper pipe from reacting with hot chlorine gas (well maybe a passivating layer of fluoride but realistically no). Seems to me like using glass would be more practical.
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[*] posted on 25-8-2010 at 07:51


I wonder what would happen if you used a microwave instead of the bbq :o

with a glass tube ofcourse. That would be interesting to look at, just to see the reaction going on (hopefully with sparking).

[Edited on 25-8-2010 by Chainhit222]




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[*] posted on 25-8-2010 at 16:48


Cool and all but for once can people try to keep things in the thread they belong instead of starting a new thread? This is atlest the third AlCl3 thread in the last month alone.




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[*] posted on 26-8-2010 at 01:45


Ohh yeah sorry about that, if someone could merge this thread with chainhit's that'd be great :)
Yeah if you look in the third picture I had a female-female joiner to the condenser piece that I pulled out, stuffed a wad of fiberglass in the open reactor tube and then cleaned. I might try and make a jacket because the wet cloth wasn't doing the best job. I found a fluorescent tube on my old fishtank, it's just bigger than 24mm so ground glass with foil should work well :cool:
I think it was mostly CuCl2, there was however a layer of white crud that wouldn't wash off the inside of the tube, that could be CuCl. It should change to green eventually if it is. I'm pretty sure what I collected was AlCl3 though, it fumes in water and doesn't show any blue or green colour in the solution.
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[*] posted on 26-8-2010 at 22:51


I suggest a merge also, as it's a direct follow up from chainhit. [edit: can the merge privilege be given to the authors of the threads? That may alleviate some stress on the moderators]

I'm not sure microwaving it would be a good idea. Microwaves tend to reflect off anything metallic, which is somewhat the opposite of why people are trying them in labs now (with charged organics, like double bonded rings with halogens sticking off, they seem to be absorbed fairly well and cause the charge to shift).

Microwave ovens also use the items inside them to limit their load, and 'light' from the magnetron reflecting back at it may upset it over long durations.

If you have major fuming issues, the product certainly won't be anhydrous. It'll retain some degree of Lewis acid potential but, if a significant amount of water gets in, it's not going to do anything positive. A bigger issue than it loosing some of it's Lewis acid potential is it gaining Brønsted-Lowry potential. The former steal electrons, the latter gives away hydrogens. Having the latter floating around will allow the former to begin behaving in ways that you may not want; side products, tar. As you may have seen in my thread, as blogfast, entropy, watson and I debate the matter, I'm fighting off minute quantities of water, and it's still creating issues.

Watson made an excellent reply with the details for producing a dry(er), clean(er) stream by passing it through activated carbon and then silica. That would probably work even better if you used a separate 98% sulphuric drying stage, then the carbon. If it's not dry, odd acids out the end. If it's not going through carbon, sulphuric in the stream (which may be why your pipe began going funny); the solvent in mine has now gone a deep orange / brown, despite the aluminium being clean, the DCM being redistilled from CaCl2 and the entire thing being borosillicate connected with the very best tubing and grease I can buy (sulphuric is creeping in there)

I've been following these threads, thinking about my own (and working on it bit by bit) and wondering if we're not both going about this in a somewhat over complicated way.

The point of mine was to make it clean, avoid the clogging, the baking and preferably end up with something easily pourable / stirrable; whether the halogen came from HCl(g), Cl2, it went straight on just aluminium or aluminium primed with another halogen or salt. And, and, hopefully discover some more about the temperature dependence and other variables.

Here's some technical details with regards to temperature's effect on chemistry

The maths of that finds that a number of reactions already posses their activation energy, but function at a commercially crippling rate when not heated (as you would expect).

One method that seems to be getting overlooked is to purposefully produce the hydrate with hydrochloric, then simply dry it under a stream of HCl(g). It decomposes at 300C; to the oxide in air, and release HCl(g) under inerts. As with hydrated FeCl3, it would likely need to be under a stream of HCl(g) for drying to function; that's not an issue for people who already used to handling that kind of thing in the first place. My hotplate will easily manage 300C.

If it's the hexahydrate as the starting point, that will be a fair amount of gas to carry the moisture off. Theoretically, the direct to anhydrous methods will be using a 1:3 ratio of aluminium to gas. Then you have to factor in for how well it's being absorbed in the first place, and you're not far off the 1:6 of drying.

Only issue with that, for me, is that I expect some clumping will ensue. For fairly obvious reasons, I don't want to fix those with grinding.

Someone also suggested (sorry, can't remember who), ether is a good solvent from anhydrous AlCl3, and can even carry it over in a distillation. That may offer someway to pick up the lumpy results and then drop them back out in a finer, possibly post distillation, form. I haven't had much luck finding it's solubility in a good number of solvents. DCM is not a great solvent at all. Water is... :D

[Edited on 27-8-2010 by peach]




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[*] posted on 28-8-2010 at 02:47


I had another try with a glass reactor tube and a CO2 generator to push the AlCl3 vapour through the tube. Here it is before the Cl2 was started:


You can see the Al glowing and reacting once the Cl2 was started:


There was heaps of AlCl3 in the copper tube I was using as a condenser, the only problem is that is was stained bright orange with a contaminant from the muffler sealing tape I used to attach two bits of glass tube together. One of them was too small for the copper pipe and the other fit it well. This tape eventually ruined the experiment, lesson learned I suppose. Here is what I got from the first scraping of the tube:


Here's that damned muffler tape:


The reactor tube snapped while I was trying to fix the muffler tape, filling the entire shed with Cl2 and HCl.


I quickly scraped what was left from the condenser, here is the finl yield of the two scrapings that will definitely have to be resublimed to clean up:


My lungs hurt :(
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[*] posted on 28-8-2010 at 03:04


Quote: Originally posted by spong  

My lungs hurt :(


I know that feeling. Cl2 seems to be even better at producing it, since it seems to go 'smell-less' once I've been breathing it for a while.

Congratulations on the result, get us some picture of the sublimation and end result. ;)




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[*] posted on 28-8-2010 at 03:30


Ohh yeah, Cl2 is the worst, you can't tell you're breathing it after a while, at least HCl alerts you. I smelled one of the reducing fittings that had cracked on the last drying tube from the Cl2 exposure and for some reason it really hurt my nose, it was ridiculous, much worse than HCl. Why would that happen? It had been sitting out in the air for days since it last had Cl2 in it.
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[*] posted on 28-8-2010 at 09:00


I had my 200g CaCl2 loaded HCl(g) generator sat out in the garden, in the very damp, rainy weather, for three days last week. It was still fuming enough to be a major pain in the ass to when it came to rinsing it out.

You're dead on right about the difference between the two and being alerted. There is no way you'll ever mistake HCl(g) or not notice it, chlorine on the other hand...

At one point I was putting together a mycology laboratory for a company in the US. One of the final things I did to clean it up to something approaching a reasonable standard was to spray and wipe down every single surface in the room, including the ceiling, with 15% industrial bleach (which was greeny / yellow and contained no special additives); wearing my bunny suit, mask, oversocks, gloves and with the flow hood on full. I could easily smell the chlorine.

Two or three hours later, I couldn't smell it. When I left the room, my lungs were a bit sore. A day later, it felt like I'd been whacked in the chest with a baseball bat.

That wouldn't have happened with HCl(g).

I discovered a very handy and cheap method to vastly boost the cleanliness of the room. Buy a big roll of decorators heavy gauge plastic sheeting, glue it to the walls, ceiling and floors, tape up the seams... super smooth, no dust, no leaks, wipe clean.

Chloride ions in the mucus lining of your lungs control the thickness of the mucus. Cystic Fibrosis suffers don't have enough. Breathing chloride donating gases isn't a great idea, and can cause your lungs to flood, encourage pneumonia and so on, but it will also thin out the mucus, for that crisp fresh air feeling the next day. :P

[Edited on 28-8-2010 by peach]




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[*] posted on 28-8-2010 at 13:14


Smells like victory.


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[Edited on 28-8-2010 by Chainhit222]




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[*] posted on 29-8-2010 at 07:01


Urgh your poor lungs :/
I tried again today, at first I had a glass condenser set up made from the same sized tubing as the reactor tube but I broke it as I was putting it all together so I used the copper one again. There was no contamination from the muffler tape this time but it was still a similar yellow colour, probably from small amounts of iron in the foil, it's still better than the black commercial stuff though. The contaminant from the tape was the greyish colour to the yellow powder and the red/orange or black coating on the lumps of powder.
I only got a small amount this time, the gas cylinder ran out just as it was getting started :mad:

Yours was off-white wasn't it chainhit? What kind of Al foil did you use?
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[*] posted on 29-8-2010 at 08:03


I got a slightly yellow offwhite product. That Al foil is like 1% iron, so thats where it comes from. I used some cheap offbrand aluminum foil iirc.

I don't remember if it was more or less yellow then yours, looks about right

[Edited on 29-8-2010 by Chainhit222]




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[*] posted on 29-8-2010 at 09:57


Very nice. I should have tried this method, but got so fed up with the DCM method I moved on to other things. I will give this a try I think. Some good engineering here could produce a very nice semi continious reactor.




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[*] posted on 29-8-2010 at 21:17


Quote:
the gas cylinder ran out just as it was getting started


Again, I've had that happen a couple of times.

"Something's wrong with this picture, [glances at regulator]... fffffffffffffffffffFF-urgh!"

Yellows and greens in AlCl3 can be signs of trace iron and water contamination, as chainhitter is suggesting with regards to the foil being contaminated.

The staining capacity of FeCl3 is gigantic, as anyone who's produced their own PCBs with the etch crystals will know. Even a 1% solution is first piss of the morning yellow. So low contaminations have the potential to produce pretty yellows.

The yellow, if it's not from the muffler tape, also serves as an indicator of moisture content. The anhydrous iron (3) chloride is essentially black. Moisture will then turn it yellow.

I would recommend any repeats of this method include Watson's suggestion of a separate drying and cleaning stage for the gas.

If it's staining yellow with no muffler tape around, there's likely moisture coming through from the generator. Generator -> 98% Sulphuric tube -> Activated carbon tube to remove sulphuric.

[Edited on 30-8-2010 by peach]




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[*] posted on 30-8-2010 at 03:39


Yeah it's definitely a viable method, I don't have much DCM to spare, it's impossible to find here so this was the only reasonable way. The main problem with getting it to run continuously(except for cleaning the condenser and replacing the foil) would be the gas generators, particularly the Ca(OCl)2 and HCl generator, once a good amount of liquid above the granules has accumulated the HCl usually just sits near the top, hardly reacting until I swirl it and have it foam like crazy. Bottled gasses or magnetic stirring in the generators would solve this problem. The foil should be able to be replaced relatively easily, the reaction tube is purged of the inert gas, the condenser could be removed and capped or cleaned then the inlet removed and a big log of foil the length of the tube could be quickly slid in, pushing the Al2O3 'ash' out in front of it.
Would it take much moisture to change it to that bright yellow colour? The powder has to be pretty close to anhydrous, it fumes like crazy around moisture, I dumped the AlCl3 and unreacted foil from the last run into a bin and poured in a flask of water, the thick pillar of HCl that erupted from the bin was ridiculous, I should have filmed it.
I'll get some activated carbon at the pet shop and fill another bubbling flask with it as I don't have another tube to use. I'll also get some more gas for the BBQ :P
I might test some in a Friedel-Crafts alkylation of toluene to mesitylene some time soon to see if the hydrate is much of an issue.
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[*] posted on 30-8-2010 at 04:56


If you can't get DCM easily, forget the bottled gases. I've been trolling those guys super style and they don't want to hear from the public, it costs a fortune for the gas and you need very expensive, special regulators. Don't try that propane tank rubbish, that's a bad idea.

It's kind of odd your HCl generator foams so much, that suggests there may a surfactant or something like that in the sulphuric, or brick cleaner if your dropping it on that. Redistilling it may be an idea.

I see B&Q have now soaped up their hydrochloric.

I always add some extra to the generators in case it doesn't fully work with the amount I thought I'd need, so I don't have to open it before trying a little more.

I think I'm going to switch over to using plastic bottles for the cake part of the generators. I have all the expensive ground glass, but it's annoying to have to start jamming screwdrivers and things in there to break up the cake afterwards. Or to have the flask burst when it's rinsed.

Provided a suitable plastic is used, there's no way it'll burst and the bottles can go in the bin afterwards if anything does happen to them.

The DCM method, if it works with HCl alone, or primed aluminium, is not as simple as it seems. Moisture appears to be far more of a problem than when the reaction is being run hot.




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[*] posted on 30-8-2010 at 06:25


Yes, so things to do. Design rock solid gas generator. It must have stirring and probably two reaction vessels, so that one can be taken off line and recharged while the other continues the reaction. As peach said it must also produce bone dry gas. Using a carrier gas to drive things is a great idea and will take some strain off the generator. Pressure spikes and back flow is a pain with them. We need to find the right kind of plastic or use stainless steel maybe. I see a large swage lock purchase in my future.

I would design the tube reactor so that you have the ability to quickly swap out a tube when one is done and load in another. Also having the ability to bring a second condenser online as one clogs will be be helpful. Glass tube is a must. What is the optimum temp for this? I like the muffler tape for the seals but there has to be some kind of high temp stopper material.

Looks like another piece of the puzzle just fell into place. Really nice work guys.




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[*] posted on 30-8-2010 at 06:57


I don't think there is any surfactant, I've been using the same stuff for a while, it's usually just when I leave it dripping and get a large layer of HCl on top and then swirl it because it's not doing anything, then suddenly it all reacts and bubbles up with chlorine, once it even made its way over into the drying tube.
Yeah emptying the broth from the generators was also a pain, having to hold my breath and open the chlorine generator and carry it outside to dump and then refill with hypochlorite wasn't the best, the CO2 generator I used for the last attempts made things easier though, I could just flood the chlorine flask with CO2 and then replace it slightly more safely. Flowback shouldn't be much of an issue though, as long as there is a bit of resistance at the condenser end, temperatures are kept relatively constant and the gas generators are air tight then everything should be ok.
Interchangeable reactor tubes would be ideal, if only I could get some ground glass tubes it would be so much easier, the fluorescent tubes are so fragile and hard to work with, I have to melt the ends to get rid of any sharp edges or cracks and then mould a foil seal to the melted end for the condenser or gas inlet, usually breaking the end and having to remelt it and start over :mad: I'm not sure about the optimum temperature, the best estimate I have is 'medium-high' according to the BBQ thermometer, from all 4 burners at full.
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[*] posted on 30-8-2010 at 07:47


@Impy

I haven't heard from you in a loooooooong time.

I've never bothered with stirring the generators, since I use salt all the time and the gunk is far too thick to stir even with an overhead. Never had too many problems with pressure spikes either. The only time that's an issue is when something in the wash bottle is solidifying and then clogs the dip tube. Which almost universally happens when I switch the stir bar off in the flask to see what's happening and what's evolving where. I purposefully leave a stopper unclipped around the generator somewhere, which then pops off if the dip tube clogs.

Neither do I really bother with a carrier gas. One goal should be to keep the dead volume in the flasks and tubing short, so the gas doesn't end up sat in those, doing nothing. Purging it with carrier once it's done would be okay. Again, I tend to just add a tablespoon more salt and sulphuric in the first place to save the effort of sorting the cylinders out.

I find using a carrier gas to be precisely the opposite of what I need. I'm usually struggling to get the gas flow as minute as possible, so the reactive gas won't blow out of the exhaust before it has a chance to get to work.

One could easily set this up to have tubes that are continuously swappable by using an oblique (two way) stop tap on the generator's output, to swap it from one path to another as the tubes are swapped. A more 'fun' prospect is handling them whilst they're roasting hot and the gas is going.

I suspect the temperature it's run at industrially is simply so they can push it through as fast as possible. As I said earlier in the thread, an experimental mind could check the temperature with a high heat variable hot air gun, using that to heat the tube. Or a variable blow lamp for plumbing work.

@spong

Ah right! I thought you were talking about HCl and didn't realise you meant the bleach and chlorine thing. Try shaking the ass out of the bottle of bleach for a while and see if there are persistent bubbles. Pure bleaches are noticeably less 'slippery' when wiped on a surface as well. You could also switch to pool shocks for more gas per unit of flask volume.

The gas is a pain, but it's still not annoying enough for me to spend £15 on a half mask. I have far bigger issues picking things up when I've forgotten how hot they are.

I do not envy you trying to do this with fluorescent tubes. They are stupidly easy to smash, indeed! I see ground glass tubes around all the time. I could pick you some up if you want. Only problem, they're usually about 6" long.

Do a yellow pages for sign makers, specifically neon sign makers. They'll have huge racks of very long borosillicate tubing in whatever size you like. That will be a lot easier than the fluorescents.

I like the temperature setting, "Produce the anhydrous acid on a slow roast, turn and cough frequently" ;)




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spong
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[*] posted on 30-8-2010 at 08:05


Oh I have been using pool chlorine, Ca(OCl)2 granules, If I had to use bleach I'd have given up by now, the strongest stuff we can get around here is about 3.5% with a lemon scent, I'd barely be able to smell the chlorine being produced :P
A 6' reactor tube would work wonders but the shipping wouldn't be too easy. I might have to give the neon sign makers a try though, with slightly thicker glass things would be so much easier, the glass would flare and shrink smoothly instead of getting little dents or lumps in it when I blow or suck from the thin glass heating up too quickly. Plus there's no mercury :D
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[*] posted on 30-8-2010 at 08:22


Isn't it 5am in Australia? :P

I'll PM you if I run into any ground tubes.




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