Sciencemadness Discussion Board - Carbon Foam Refractory Made From Bread

Carbon Foam Refractory Made From Bread

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careysub - 31-10-2016 at 06:46

Yes, really:
https://www.acs.org/content/acs/en/pressroom/presspacs/2016/...

This could be very useful for people devising very high temperature furnaces.

ficolas - 31-10-2016 at 07:37

Finally a purpose for the shitty bread they sell in my town.

Or maybe thats why the bread is so shitty, because they are secretly making carbon foam, and they sell the remaining (made with a recipe adjusted for carbon foam bread...

phlogiston - 31-10-2016 at 08:13

Is it conductive?
I wander if it is similar to the foamy carbon you get by carbonizing sugar with concentrated sulphuric acid.

The smells in that lab... it must be alternating lovely fresh bread followd by terrible burnt toast.

Texium - 31-10-2016 at 08:15

Ha, that is... actually pretty awesome. Now I'm picturing the chemists consulting professional bread bakers to get the consistency just right.

Jstuyfzand - 31-10-2016 at 08:33

Quote: Originally posted by phlogiston

Is it conductive?
I wander if it is similar to the foamy carbon you get by carbonizing sugar with concentrated sulphuric acid.

The smells in that lab... it must be alternating lovely fresh bread followd by terrible burnt toast.

If its conductive it would be the best electrode for electrolysis on the planet, high surface area and cheap.

Fulmen - 31-10-2016 at 09:04

Cool find. Here's the paper.

Attachment: yuan2016.pdf (2.1MB)
This file has been downloaded 1230 times

careysub - 31-10-2016 at 11:08

Quote: Originally posted by zts16

Ha, that is... actually pretty awesome. Now I'm picturing the chemists consulting professional bread bakers to get the consistency just right.

Hah! This is were "kitchen chemistry" gets serious. Break out the yeast and flour and set to work guys (and gals)!

aga - 31-10-2016 at 11:38

Odd.

I watched a utoob vid a while back by AvE (probably no relation to ave) doing exactly this with sliced bread.

https://www.youtube.com/watch?v=Wex_yKfrTo4

careysub - 31-10-2016 at 13:55

It was put on YouTube four days after the posting date of the ACS item, so it may well have been inspired by the published research.

Also, it would appear that he is using commercial batter-whipped bread not properly risen kneaded dough, which can achieve a dense even porosity (or even a not-dense even porosity) - notice the huge pores that are present!

An even texture will always be important for consistent, uniform properties.

[Edited on 31-10-2016 by careysub]

aga - 31-10-2016 at 14:19

'Odd' in the sense that it clearly shows that i watch more utoob than read academic papers.

Didn't think i was that facile and shallow.

I'll have a Word with myself.

Maroboduus - 31-10-2016 at 18:12

This sounds like a very economical process.

And if any of the slices come out looking like Elvis or Jesus you could sell them on Ebay for a hefty profit!

Scalebar - 1-11-2016 at 00:57

Nice find. I'm trying to put a furnace together myself for metal work. I wonder if excluding air would be sufficient for the carbonisation to work. A really lazy way might be to fill out your insulation cavity with bread then fire up the furnace - anywhere that gets hot enough will carbonise and the rest will presumably just toast and dry out.

aga - 1-11-2016 at 04:56

Today's All Saints day, or 'Dia de los Muertos', so it's a day off.

What better way to spend it other than to pyrolise bread ?

Two slices of bread (one a dense brown, the other white) were weighed at 31.75g and 32.50g respectively.

The samples were prepared (wrapped in tinfoil) and introduced into the custom-built pyrolysis apparatus (a wood fire).

The fire was left to burn for 1 hour and the bread samples were recovered and allowed to cool for 5 minutes.

The brown slice had disintegrated almost completely, the largest fragment being approx 2cm across.

The white slice had entirely retained it's shape, although the size had decreased by approximately 50%.

It weighed 5.35g, representing an 83.5% weight loss.

Under a cheapo USB microscope, the material appears very porous.

Those lines are 1mm spaced.

I wonder how this will fare as a method to activate carbon ?

One way to find out ....

[Edited on 1-11-2016 by aga]

j_sum1 - 1-11-2016 at 05:04

Lovely aga.
Interesting that the white performed so much better than the "healthy" bread.
What I find remarkable about the report is the claims of mechanical strength.
If this proves to be a route to reasonable quality activated carbon then it is certainly cheap, simple and easy to do. I look forward to seeing your results.

aga - 1-11-2016 at 06:40

The 'bread' is now rigid, yet breaks if you try to bend it, although it does not just fall apart.

Before doing the I.N. thing, i thought i'd test the bread's heat resistance.

Here's a piece with some copper melted on top of the bread with an electric arc.

Neither the arc (2000+ C) nor the 1085 C copper appear to have bothered it at all.

[Edited on 1-11-2016 by aga]

aga - 1-11-2016 at 09:57

Incredibly, the slice of bread from Lidl, wrapped in tinfoil, then stuffed into a fire for an hour, achieved an Iodine number of 486 !

(500 is regarded as the lowest I.N. for it to be regarded as 'activated').

battoussai114 - 1-11-2016 at 14:22

I wonder how doing this under a nitrogen atmosphere would change the results. Once the Día de Muertos ends I'll try to get some parts from the closest hardware store to get a high temperature controlled atmosphere setup running.

Quote: Originally posted by aga

Incredibly, the slice of bread from Lidl, wrapped in tinfoil, then stuffed into a fire for an hour, achieved an Iodine number of 486 !

(500 is regarded as the lowest I.N. for it to be regarded as 'activated').

Without chemical activation? pretty nice!

Jstuyfzand - 1-11-2016 at 14:28

Aga, have you measured the electrical conductivity?
The paper mentioned a conductivity of 0.26S/cm, which seemed reasonable.
I wonder what numbers your high tech equipment could achieve.
*asking for a friend...*

aga - 1-11-2016 at 14:41

Dunno.

Didn't test electrical resistance. Probably in the Mega-Ohm range.

The post shows it all : bread, some aluminium foil, a fire, 1 hour, you got the same material.

This is not hard to do, at all, for anyone.

Edit:

aga is spelt aga, not Aga.

I'm not the Aga Khan.

Sharim might get annoyed if this keeps going on.

He might be Googling for stuff about one of his many multi-million dollar ventures and get a load of Toast, Carbon and failed chlorination of ethanol results.

[Edited on 1-11-2016 by aga]

aga - 1-11-2016 at 15:15

Quote: Originally posted by battoussai114

I wonder how doing this under a nitrogen atmosphere would change the results.

Might change it, but harder to Try.

I think that just wrapping the slice of bread in more layers of Al foil would have worked better, say about 6 wraps (i used 2).

The dense bread was fubar in my experiment, but the Al foil had disintegrated as well, letting air in.

I was lucky that i tried with 2 samples.

JUST DO IT and report results - no need for complexity, it's just a slice of bread wrapped in tinfoil in a fire.

Might work in an oven (250 C) too. No idea, not tried it.

This particular experiment requires NOTHING that people do not have access to.

No expense required, apart from the Time.

If you have any interest in the material, just make some as has been fully described.

It is a Wicked material, at least as far as heat resistance and carbon 'activation' are concerned, probably a Lot more.

I zapped some copper to 1000 C+ on top of a slice of Toast today, and the toast survived !

Awesome.

j_sum1 - 1-11-2016 at 16:02

Well, when the process is refined and tested, it deserves its own published procedure in the wiki -- as does making potato starch for use as an indicator.
(Are there any other similar processes that need to be written up? And by similar I mean very accessible using household items, straightforward procedure and producing an invaluable lab consumable for the home chemist that most professional labs pay reasonable bucks for.)

aga - 1-11-2016 at 16:06

Go for it. You da man.

I just zap, burn and boil stuff up.

Give it some Science spin dude !

j_sum1 - 1-11-2016 at 16:27

Ok. Well in time I can do that. So far there are two on the list:

Starch – for which I will write up NileRed's procedure
Activated carbon (aka super-toast) – for which I will summarise the procedure and results of this thread. So long as you post your findings aga I can do the deed. With my current state of affairs I cannot see me getting the chance to quantitatively test any super-toast any time soon. I would be interested to know if pre-treating the bread with something will elevate the product from good to awesome.

What other procedures of this nature deserve to be written up?

careysub - 1-11-2016 at 18:11

I will bet that both nitrogen and carbon dioxide will work pretty well. After all carbon is pretty inert with respect to nitrogen and carbon dioxide (and water).

Aga is probably creating the latter atmosphere with his foil-wrapping procedure.

Pyrolyzing the bread (with some intrusion of air) will produce water and CO2, and while there is the Boudouard (CO2 + C <-> 2CO) and water-carbon (C + H2O <-> CO + H2) reactions exist they are sluggish equilibrium reactions, and there is huge excess of carbon in the system.

Isn't this sort of how they make charcoal?

aga - 2-11-2016 at 00:12

Quote: Originally posted by careysub

Isn't this sort of how they make charcoal?

Pretty much the same, yes.

The main (only ?) difference is in the structure of the end result - the bread is less dense.

Retaining the structure durying pyrolysis is the hard part when it comes to making things like a carbon aerogel.

http://www.buyaerogel.com/product/carbon-aerogel/

Jstuyfzand - 2-11-2016 at 05:01

I wonder how different temperatures affect the structure and properties, I recall reading that higher temperatures lead to more graphitization, which would benefit the electrical conductivity.
Too bad temperature control is not easily done in a wood fire, you'd need a kiln of some sort.

aga - 2-11-2016 at 07:12

Quote: Originally posted by Jstuyfzand

Too bad temperature control is not easily done in a wood fire

Add more wood.

Blow air through it.

Use charcoal instead of wood.

Use coke instead of charcoal.

Jstuyfzand - 2-11-2016 at 07:54

Quote: Originally posted by aga

Quote: Originally posted by Jstuyfzand

Too bad temperature control is not easily done in a wood fire

Add more wood.

Blow air through it.

Use charcoal instead of wood.

Use coke instead of charcoal.

*Precise* temperature control I correct myself.
But your way will work, and produce different results, what its all about.

aga - 2-11-2016 at 08:16

'Precision' is a relative term.

In the good old days when people Did stuff and were not enslaved to the internet, the temperature of a furnace was guaged by the colour of the flame/coals/lining bricks.

Steel workers could give you an estimate to +/- 20 C for the range from about 500 C to 1000 C, and better accuracy below 400 C, all simply by the colour of the metal.

Hardly 'precision' but certainly a degree of Control.

http://www.stormthecastle.com/blacksmithing/blacksmith-steel...

Reminds me of the way that electricians used to check for the presence of high voltages.

They'd use a piece of pine wood, jam it onto the contacts, then slowly run their hand up the wood to see if they got a tingle ! Crude, but worked.

yobbo II - 2-11-2016 at 10:08

When this is done to wood it turns to charcoal and will burn. When done with bread it turns to carbon that is a refractory.
Perhaps the wood is not being heated enough to turn it from charcoal to refractory carbon?
If it worked with wood it would be great . You could carve out the shape you wanted, say a box shape for a furnace to be, fire it up and you have a carbon box. Just add the door and elemetns.

The original pyrometer

MrHomeScientist - 2-11-2016 at 10:36

I'm sure the density difference is why wood doesn't turn into 'super wood'. Bread is far more porous.

This would be a neat experiment to try for sure. What's your procedure for determining iodine number?

aga - 2-11-2016 at 11:39

Quote: Originally posted by MrHomeScientist

What's your procedure for determining iodine number?

The ASTM procedure.

http://www.sciencemadness.org/talk/viewthread.php?tid=63181

There's a link to the full document which details the procedures and calculations.

In breif, grind up then weigh sample, add 5% HCl and boil 30 secs to remove sulphur, add 0.1N iodine solution, filter, titrate some filtrate with 0.1N sodium thiosulphate solution.

Standardisation required KI as well.

careysub - 2-11-2016 at 11:59

Quote: Originally posted by MrHomeScientist

I'm sure the density difference is why wood doesn't turn into 'super wood'. Bread is far more porous.

It is part of the answer. Bread is not only porous, it is uniformly porous in three dimensions (if you knead it right), and yes has much lower density.

Wood's porosity is not uniform, but tends to the "bundle of straws" model.

Another factor with wood is that charcoal making is actually exothermic over much of the heating range, which is involved with the depolymerization of lignin, not found in flour. This is quite different from carbonizing bread.

But is you tried carbonizing the very low lignin, highly porous wood called "balsa" you would get something similar to the bread carbon foam, I expect, but again - it is a bundle of straws and would be strong in only one direction.

And some charcoal is "super wood" - look at activated charcoal which is (or can be) hard and porous and a decent insulator.

[Edited on 2-11-2016 by careysub]

aga - 2-11-2016 at 12:07

The next obvious step is to find more porous starting materials and then think of ways to 'dose' them with some reagent(s) before pyrolysis to increase the surface area further.

The key, i assume, is understanding why the carbon remains in a relatively strong matrix post-pyrolysis, and does not end up as a pile of black dust.

Perhaps pre-treating is what S.C Wack and Sulaiman alluded to, although i have found no evidence that it is beneficial to do so.

[Edited on 2-11-2016 by aga]

careysub - 2-11-2016 at 12:36

I agree with Aga, this topic is good one for further amateur work at extending it.

aga - 2-11-2016 at 12:49

Having read the scientific paper, it's clearly a bunch of chancers with access to some great analysis gear who just made some charcoal.

Good on 'em !

This field is wide open to literally Anyone who has an interest in it.

Plenty more materials out there to try out.

I guess the Target is important - what properties are the most desireable ?

Surface area
Heat resistance
Structural integrity
Electrical conductivity
Chemical inertness

[Edited on 2-11-2016 by aga]

[Edited on 2-11-2016 by aga]

careysub - 2-11-2016 at 13:41

My particular interest is its usability as a high temperature insulator.

Above 1650 C there aren't many options - Kaowool 3000 gives out at this temperature, as does even ultra high temperature castable refractories.

That this material is good to at least 2000 C is notable. There are other carbon products out there (graphite felt, etc.) but most of them are either not suitable for insulation or readily available to the amateur. The ability to manufacture this stuff in quantity very cheaply and to desired shaped is a big deal.

One thing that is lacking in the paper information about its performance as a thermal insulator at high temperature. The conductivity of all materials goes up with temperature, and room temperature region conductivity measurements are at best an indirect measure of high temperature performance.

Unfortunately the best insulating value was found for incompletely pyrolyzed bread, while at high temperatures obviously pyrolysis is going to completion even if it didn't at the manufacturing stage.

At least the fact that it is black bodes well - radiation is a major heat transport mechanism in porous solids at high temperature.

j_sum1 - 2-11-2016 at 14:47

This seems like the kind of thing deltaH would be interested in. A shame we haven't seen him for a while.

Aga, tell me about the mechanical properties. In my mind I cannot get past the image of burnt toast which is really brittle and crumbly. It is notable that the shape of the material distorts on pyrolysis. This is not an issue if your intent is to grind it up to powder. But if you want it as a refractory then there are additional requirements.

careysub - 2-11-2016 at 15:03

Quote: Originally posted by j_sum1

It is notable that the shape of the material distorts on pyrolysis. This is not an issue if your intent is to grind it up to powder. But if you want it as a refractory then there are additional requirements.

Umm... carbonize an entire loaf and carve it to shape?

A sanding block would work wonders.

For insulating a large volume (like the inside of my conceptual 10 gallon can furnace) you should bake wide flat loaves (make a "pizza box" carbonizing oven) and stack them up.

aga - 2-11-2016 at 15:10

The slice of bread, pyrolysed, retained it's shape.

To snap the resulting bit of carbon requires some effort, but not a lot.

Slice of bread, tinfoil, fire, verify all of this for yourself.

It takes just 1 hour.

I despair at these questions when you can know for yourself, first-hand, in just 1 hour.

[Edited on 2-11-2016 by aga]

j_sum1 - 2-11-2016 at 15:23

My apologies aga. I know your enthusiasm for Doing Stuff. Unfortunately my living and work arrangements at the moment do not afford me much opportunity for even something as simple as a fire in the back yard. It will all change in a few weeks. In the meantime I am involved in discussion, thinking and asking questions. So don't despair.

aga - 3-11-2016 at 10:18

Sorry for banging on about Doing stuff.

One kind member has pointed out that other people may not enjoy the same freedoms that i do, and that seeing things done is as close as they can get most of the time.

I guess i don't appreciate how free i actually am compared to others.

metalresearcher - 3-11-2016 at 12:47

Just put a roll of bread wrapped in aluminium foil into the wood stove. I am curious how this turns out...

MrHomeScientist - 3-11-2016 at 13:05

Five minutes in the library can save you an hour in the lab, or however that quote goes. If you have the experience, people might as well ask first.

I'm quite interested to try this out myself at some point.

If the goal is to exclude oxygen, I wonder if including some baking soda in the tinfoil pack would help? It would decompose into CO<sub>2</sub> and help keep air away.

[Edited on 11-3-2016 by MrHomeScientist]

aga - 3-11-2016 at 14:18

Quote: Originally posted by metalresearcher

Just put a roll of bread wrapped in aluminium foil into the wood stove. I am curious how this turns out...

Do so, and tell us how it turns out, if you're actually curious. It's not difficult to do, at all.

Quote: Originally posted by MrHomeScientist

I'm quite interested to try this out myself at some point.

Do so, and tell us how it turns out.

Enough words about toasting bits of bread.

Time for supposedly Amateur Chemists, members of ScienceMadness.org to demonstrate that they can, at least, make Toast.

An Egg on top is optional.

Texium - 3-11-2016 at 14:49

You know aga, you're the one who's been Talking the most in this thread by complaining about people not Doing Stuff after you did one simple experiment, and it's starting to get very annoying to those of us who are following along with the thread.

It's admirable that you took the initiative and were the first one here to try it out, but you don't have to hold that over the head of anyone who wants to ask you additional questions about your results, or openly hypothesize modifications to the procedure.

Maybe you've forgotten that the experiment is not the only part of the scientific method.

violet sin - 3-11-2016 at 15:32

You have to admit it's a really easy experiment. Might be even feasable to quad rap one piece of bread in aluminum foil and cook repeatedly in a standard toaster. Beside that, aga did do a test for activation of the resultant char.

Would be nice to see a few other members content them selves with a simple toast bit now, use that product to do more pondering on for a latter more scientific approach. And get aga to do a round 2, perhaps with activation chems from his other thread, an easy to reproduce method using common lab glassware pieces, testing further blanketing effects etc.

I got off work a bit early today and am really going to do at least one piece to check it. Mind you I'm outta town working and have no "lab" to speak of. Just some electronics project stuff, adjustable power source and some plating chems. Not work related, just for hobby.

Which has me wondering if it will take a Ni coating. Hopefully I'll get as much done soonish. The plating bath, may be tricky. Nice green colored sol. full of soluble Ni around children is ill advised unless properly planned. He will be 3 in January so... all go and not so much a ponderer of consequences

j_sum1 - 3-11-2016 at 16:50

Let me throw out another possibility for this process. Suppose you pre-soaked your bread in a solution of Pt salts. Might you then get a catalytic product with a really high surface area? It could be rather useful.

(Now, it would be nice if this brought the Ostwald process within the range of home chemists but with the oxidising conditions the supertoast™ won't survive.)

[/random ramblings]

TheAlchemistPirate - 3-11-2016 at 16:54

Just an hour ago I made burnt toast.

I took 2 slices of white bread, pushed them together, then wrapped the whole deal in 10 layers of foil. I followed the usual procedure for making charcoal, putting the bread and foil in the hot coals of a campfire. After an hour I got a black mass looking very much like a squashed piece of toast (the two slices had "morphed" together) .

After cooking, the two slices (now one piece) weighed 12.52 grams. I didn't weight the bread before cooking though.

I tested the electric resistance with a multimeter set to 2000 kOhms, and couldn't get a reading even with the electrodes right next to each other. It is a very good electrical insulator it seems.

As far as mechanical strength, it is actually a fairly sturdy material. It took some force to snap it by twisting, and pulling a piece apart with my hands took several seconds. Imagine snapping a pencil in half, but a little weaker.

Tomorrow I will apply the blowtorch to it, and see how that goes.

Oh, and here's a picture-
http://imgur.com/0SROKxF

violet sin - 3-11-2016 at 18:10

Jsum: I was looking through patents for something posted some time ago, leaves/roots retted down to the skeleton were soaked in iron acetate and baked in nitrogen gas to make iron carbides.

Anyhow came across some patents for lignin/cellulose/asphalt substrates which were bound with quaterntary amines to form functional sites, then metal ions were chelated to the sites and it was toasted with a microwave at attainable conditions to form nano metal oxides in matrix. But for some reason every time I coppy and paste a link from my phone, it crashes the browser... Super annoying. So hand coppied: https://www.google.com/patents/US20130233802

There were others, but its family time atm.
[Edited on 4-11-2016 by violet sin]

[Edited on 4-11-2016 by violet sin]

j_sum1 - 3-11-2016 at 18:38

woot! I wil look that up when I get a chance. But it does sound more complex than burnt toast.

Morgan - 3-11-2016 at 18:40

Quote: Originally posted by j_sum1

Let me throw out another possibility for this process. Suppose you pre-soaked your bread in a solution of Pt salts. Might you then get a catalytic product with a really high surface area? It could be rather useful.

(Now, it would be nice if this brought the Ostwald process within the range of home chemists but with the oxidising conditions the supertoast™ won't survive.)

[/random ramblings]

If you could platinize and char a slice of bread, how amusing it might be to lower the whole piece into a vessel filled with methanol vapor to behold catalytic glowing toast.

Texium - 3-11-2016 at 21:11

Quote: Originally posted by j_sum1

Maybe not for the Ostwald process, but that could possibly be a good, easy way to generate palladium or platinum on carbon catalyst for hydrogenations!

metalresearcher - 4-11-2016 at 00:11

I took the 'bread char' out of the cooled wood stove.
The 'bread char' is very fragile. It breaks easily apart.

aga - 4-11-2016 at 01:43

Action ! Woohoo !

I guess the next step will be to make bread with Other ingredients added and see if we can :-

a) get some kind of regular shape

b) make it into something useful

Electrodes and/or catalysts sounds promising.

Morgan - 4-11-2016 at 08:41

Seems like a very fine grain bread would make a stronger carbon foam, a dense bread with smaller pores. You see platinum on alumina and platinum on carbon, but does it have any benefit to make a carbon/alumina combination? Or maybe add alumina or aluminum hydroxide to the bread mix hopefully as a binding agent to strengthen the friable carbon foam.
Yesterday I came across this noodle matrix technique and wondered if a fine noodly lattice could be baked into a carbon fiber cross-linked morass of some sort.
2,4,8,16,32,64,128, 256 I've seen a baker get to 1024.
https://www.youtube.com/watch?v=RCWfAhuUaU8#t=23
https://www.youtube.com/watch?v=L54-cInHrg0

A sugar approach
https://www.youtube.com/watch?v=euaEvOdk2Sg
A good presentation with countdown
https://www.youtube.com/watch?v=odL8JdQpMs4

Maybe baking bread under pressure in a hydrothermal synthesis vessel would be of some benefit or a useful pretreatment method.

[Edited on 4-11-2016 by Morgan]

Maroboduus - 4-11-2016 at 11:02

Morgan's thoughts on pore size make a lot of sense from a structural point of view.

But there is the question of whether gluten development affects the final product as well.

The more a dough is worked, the more the gluten is 'developed', leading to cross links which make a more resilient bread. Sort of like denaturing egg whites when you cook them.

I have no idea if these cross links would change the nature of the final product after the oven treatment, but it seems possible that this could lead to greater bonding strength because although these cross links are wiped out in the carbonization, they may hold the molecules in more intimate contact long enough to encourage other cross linking to form as the product carbonizes.

It's difficult to judge baked goods from photos, but it appears that aga's sample may be a fairly robust material with well developed gluten to give it substance in spite of it's large pores. This contrasts sharply with the common sliced breads with a softer texture (for readers from the US, think Wonder Bread, or Kilpatrick's white sandwich bread, in Mexico, Bimbo's sliced sandwich bread is similar)

This difference may have some influence on the strength of the final product.

It might be helpful if those reporting results included what information they can about the texture, pore size, chewiness; and of course for mass produced breads, the brand.

Maybe all breads work well, but if variable results are reported this may be part of the answer.

Of course the nature of the conditions of carbonization is no doubt more important. getting that right is obviously critical.

ficolas - 4-11-2016 at 11:16

What about adding small metallic (copper for easyness and cheapyness, platinum for goodness) particles to try to increase conductivity, and then if the copper doped bread char is conductive enough, attempt to electroplate it with metal?
Could that work?

aga - 4-11-2016 at 11:36

'Bimbo' must be a Hispanic bread brand, 'cos i can get that here and will do so tomorrow.

Quote:

like denaturing egg whites when you cook them

Meringue !

That's also full of bubbles (adds eggs and caster sugar to shopping list)

Lo ! I forsee Fire. Lots of Fire, with bits in it, carbonising.

violet sin - 4-11-2016 at 12:03

My attempt last night failed, burn through. Impatients placed it too close to the really hot area. Also bread on hand was seedy. So today gonna hit the stores up and get more prefered materials. I want to do sourdough because of large pores. Should be better for depositing Ni with out closing out as much interior surface. Thinking dollar store for a thicker Al pie pan/turkey tray or the like to enclose around standard foil wrapped bread. Charcoal also instead of the wood stove should provide more controll, maybe a meal to boot. Check back in when something works out.

aga - 4-11-2016 at 12:08

If at first you don't succeed ...

We now have two photos of an experiment with a result at the end, so it can definitely be done.

I got lucky by trying two types of bread at the same time.

If i'd just used the brown bread, there'd be nothing much to see.

White Wonder Bread seems to be the #1 choice.

Jstuyfzand - 4-11-2016 at 12:29

Quote: Originally posted by aga

If at first you don't succeed ...

We now have two photos of an experiment with a result at the end, so it can definitely be done.

I got lucky by trying two types of bread at the same time.

If i'd just used the brown bread, there'd be nothing much to see.

White Wonder Bread seems to be the #1 choice.

AvE used the white wonder bread too, worked very well for him too.
It even resisted a oxy-acetylene torch, with a temperature probe behind a 2 cm slab of bread, it only reached 80C.
This stuff has potential.

I am finishing my 1000C kiln soon, I will try to put a large piece of bread in it too see how it performs as a brick.

battoussai114 - 4-11-2016 at 12:35

Bimbo is indeed a Mexican brand, but they're actually present in the Americas and also Europe (and they own the brand that makes Twinkies too).
Sounds like a decent option to standardize tests from members.

careysub - 4-11-2016 at 12:48

Quote: Originally posted by Maroboduus

Morgan's thoughts on pore size make a lot of sense from a structural point of view.

But there is the question of whether gluten development affects the final product as well.

The more a dough is worked, the more the gluten is 'developed', leading to cross links which make a more resilient bread. Sort of like denaturing egg whites when you cook them.

I have no idea if these cross links would change the nature of the final product after the oven treatment, but it seems possible that this could lead to greater bonding strength because although these cross links are wiped out in the carbonization, they may hold the molecules in more intimate contact long enough to encourage other cross linking to form as the product carbonizes.

Gluten development is essential for establishing the pore structure of yeast-risen bread. You cannot use baker's yeast to leaven rye bread that has low gluten. The physical structure of the bread prior to pyrolyzing must affect the final structure.

violet sin - 4-11-2016 at 23:33

Got it to work. Took more care and a few bucks, $4.50. But a plastic insert stainles steel coffee cup from the thrift store was stripped to just the stainless shell. Safeway bakery -european french bread, cut to size, wrapped in dollar store Al foil and ends twisted, put in ss cup shell, Al foil over top, aluminum cat food can( free) covering top but fits just inside the ss shell, then the top covered in a couple pieces of foil. Put in wood stove used for heating a home. 1/2 hr leaning on few coals- rotated on 15 min, another 1/2 hr in warmer parts, repeat for a total of 2.5hr with final half hour cup glowing red on one side in a the hottest part of coals.

It now clinks when jarred and feels sturdy. Tomorrow I'll cut it up a bit to hopefully make some test squares. Try some soak in and reheat additives to increase conductivity or something. Hate to set up Ni bath and clean it up if there isnt enough conductivity to strike something on. Well, there ya go, did some toast burning. No scale to calculate loss on charring.

aga - 5-11-2016 at 00:32

Superb !

I think that is the largest single chunk anyone has made so far.

Morgan - 5-11-2016 at 06:56

Tidbits and free associations

Maybe the structural strength could be improved by adding some chopped carbon fiber sans resin to a bread mix.

Another approach might be to try building up the strength of a carbon foam shape by dipping it in a liquid bread dough and do consecutive baking, adding layer upon layer, if perchance that was adventitious.

I'd like to see a carbon foam that would be airtight and lightweight in the form of a tube able to handle HIGH temperatures and most of all low cost. It wouldn't have to be very strong, but just enough to build parts for a myriad of toys and MAKE projects. Lots and lots of science projects would then be available, from toy boats to model airplanes, or structures that are uniquely offered by these qualities. Delicate toast heat engines would be fun to design, a toast to the materials science of toast.

Offhand what might be the coefficient of thermal expansion of "Wonder Bread" foam?

This stuff is heavy and costly and only good for non-combustion projects.
"These high temperature sheets maintain most of their rigidity up to 500 F, and can withstand short durations at much higher temperatures."
https://www.youtube.com/watch?v=l1Rt2dhlJB4
https://dragonplate.com/ecart/categories.asp?cID=189

j_sum1 - 5-11-2016 at 07:16

Quote:

I'd like to see a carbon foam that would be airtight <snip>

I think this is a contradiction -- unless you can somehow force a closed-cell foam. This probably excludes a bread structure.

unionised - 5-11-2016 at 07:18

Interesting topic.
It reminds me of my failed attempt to make a sponge from aluminium phosphate.
I dissolved AlPO4 in citric acid solution and soaked a cellulose sponge in it then let it dry and finally tried to burn off everything but the AlPO4.
I was hoping to get a thermal and electrical insulator but what I got was black which I took to mean that it was full of carbon. It wasn't a good enough electrical insulator for my purposes and I couldn't get the carbon to burn off properly.

Just a quick question for those who have spent some time pyrolysing bread to carbon foam:
What happens if you microwave the foam?

aga - 5-11-2016 at 08:01

Quote: Originally posted by unionised

What happens if you microwave the foam?

Er, dunno, not tried that - yet.

1 sec.

Edit:

Woot woot !

It gets all jiggy like an electric arc furnace and really annoys the wife !

It also makes a bzzzzt-bzzzzt noise, exactly like an electric arc.

I noticed some bits of Al foil still stuck to it, so broke off a smaller piece with no foil, and tried again.

It did the same thing.

[Edited on 5-11-2016 by aga]

wg48 - 5-11-2016 at 08:03

Quote: Originally posted by unionised

Interesting topic.
It reminds me of my failed attempt to make a sponge from aluminium phosphate.
I dissolved AlPO4 in citric acid solution and soaked a cellulose sponge in it then let it dry and finally tried to burn off everything but the AlPO4.
I was hoping to get a thermal and electrical insulator but what I got was black which I took to mean that it was full of carbon. It wasn't a good enough electrical insulator for my purposes and I couldn't get the carbon to burn off properly.

Just a quick question for those who have spent some time pyrolysing bread to carbon foam:
What happens if you microwave the foam?

How much AlPO4 does citric acid disssolve?

Wiki says AlPO4 melts at 1800C so a solution of it may make a great refectory binder or a flux.

I would like to know what happens to microwaved carbonised toast too. I suspect it will heat up and burn.

aga - 5-11-2016 at 08:22

Wait a sec.

If it's absorbing the microwaves, generating eddy currents in the carbon, and then arcing, it'd be like a super-susceptor.

The only susceptor i know of (magnetite) transforms the microwave to heat by basically getting hot.

This stuff bangs electric arc plasma next to what you're heating !

Morgan - 5-11-2016 at 08:46

Quote: Originally posted by j_sum1

Quote:

I'd like to see a carbon foam that would be airtight <snip>

I think this is a contradiction -- unless you can somehow force a closed-cell foam. This probably excludes a bread structure.

I wouldn't have any objection to coating the carbon toast foam with some sort of refractory sealant if that would work.

Here's some comments from this video clip. I don't see why you necessarily have to use bread to make a carbon foam though. Do traces of protein in the bread help at all and if so maybe something as ridiculous as hagfish slime could be used in the dough.
http://www.iflscience.com/plants-and-animals/hagfish-slime-b...
Cotton fabrics are crisscrossed just as that dough clip I posted where they lay the strands atop each other perpendicular to ones below. Or maybe carbonized worms could be used to build tube structures. I was thinking a carbonized wasp nest or honeycomb beehive would be interesting maybe again coated with a high temperature glaze to shore up the fragile nature of the carbonized structure if possible.
http://oddstuffmagazine.com/mildly-interesting-things-this-o...

"Essentially that's what it was, they would cut 1 inch squares of cotton fabric like as if you cut up a white tshirt into perfect square pieces, took a handful and soaked in epoxy resin of some kind or phenolic resin and then let it cure under tremendous pressure into this plastic molded shape of resin impregnated cotton squares , they would then bake and burn off that resin leaving behind what they named carbon carbon which is the forerunner to heat abatement tiles like on the space shuttle or at least that's how he described the process in layman's terms to me. hell of a interesting engineer this guy, it was a pleasure to pick his brain"
https://www.youtube.com/watch?v=Wex_yKfrTo4

In the above clip it's curious why the foam doesn't conduct electricity.

"The creation of stiff yet multifunctional three-dimensional porous carbon architecture at very low cost is still challenging. In this work, lightweight and stiff carbon foam (CF) with adjustable pore structure was prepared by using flour as the basic element via a simple fermentation and carbonization process."
http://pubs.acs.org/doi/abs/10.1021/acsami.6b03985?journalCo...

[Edited on 5-11-2016 by Morgan]

ficolas - 5-11-2016 at 08:48

Quote: Originally posted by aga

Wait a sec.

If it's absorbing the microwaves, generating eddy currents in the carbon, and then arcing, it'd be like a super-susceptor.

The only susceptor i know of (magnetite) transforms the microwave to heat by basically getting hot.

This stuff bangs electric arc plasma next to what you're heating !

Dunno about that but what you described looked like when I microwaved a pencil. It arc-ed, made bzzzb bzzz sounds
It also really annoyed my female room mate, the male one seemed to enjoy it tho. Maybe it has some female-annoying properties.

TheAlchemistPirate - 5-11-2016 at 09:37

Interesting. I microwaved my carbon foam the other day without anything happening at all, even after trying to preheat it with a flame. I have done experiments with carbonized bamboo skewers in close proximity, which arc in interesting ways when preheated. My guess is that my carbon foam was not "cooked" enough, and that there is a large amount of charcoal in it compared to the lesser amount of conductive forms of carbon like graphite. I shall try and see...

I did torch the carbon toast from earlier, for about a minute. The piece itself stayed intact, but I observed some cracks on the surface when exposed directly to the flame.

Currently I am making my own dough, in an attempt to "cast" this carbon foam refractory in the shape of a crucible. I will update on this shortly.

aga - 5-11-2016 at 10:06

I got a couple of loaves cooking (as in normal cooking) at this moment.

Basic bread recipe this time with the salt swapped for calcium chloride and about 3x sugar than normal.

Tried this yesterday, but way overdid the CaCl₂ which stopped the yeast working, so the dough did not rise.

I think the difficulty in making these materials is not the carbonisation, but the retention of any kind of durable form in the process.

[Edited on 5-11-2016 by aga]

violet sin - 5-11-2016 at 10:34

Used an old hacksaw blade to regularize it's shape, then part it out.

Looks nice!!! Makes me wish I could sputter metals onto the surface. The outside chunks are quite strong, resist breaking and the lot still sounds clinky when jarred together.

Wondering about second and third roasts now. Gauzing up the outside of a block with cotton balls/matting streched super thin.

what about ground cherry and hops flowers? Ehh? Could get fun quickly here folk.

Was at the store grabbing food stuffs, found my self wondering about charred cheerio's with metal oxides for cheap fluidized bed catalyst supports?

[Edited on 5-11-2016 by violet sin]

aga - 5-11-2016 at 11:24

Superb ! You made my day !

Natural materials are definitely worth looking at, and trying out.

Edit:

I wonder if lightly clamping the bread between some metal plates during carbonisation would be helpful ?

It should reduce the pore size and get more material into the space = higher surface area, also help retain a shape (a slab in this case).

Clamping pressure will definitely be important - too much and it'll squish all the air/CO₂ out, too little and it'll go all warpy and bendy.

Loaf #1's gonna get clamped and toasted.

[Edited on 5-11-2016 by aga]

unionised - 5-11-2016 at 11:43

Quote: Originally posted by aga

Quote: Originally posted by unionised

What happens if you microwave the foam?

Er, dunno, not tried that - yet.

1 sec.

Edit:

Woot woot !

It gets all jiggy like an electric arc furnace and really annoys the wife !

It also makes a bzzzzt-bzzzzt noise, exactly like an electric arc.

I noticed some bits of Al foil still stuck to it, so broke off a smaller piece with no foil, and tried again.

It did the same thing.

[Edited on 5-11-2016 by aga]

Proper science!

unionised - 5-11-2016 at 11:48

Quote: Originally posted by wg48

[

How much AlPO4 does citric acid disssolve?

Wiki says AlPO4 melts at 1800C so a solution of it may make a great refectory binder or a flux.

It dissolves enough to make the solution quite viscous.
AlPO4 has a high MP, but it has some phase transitions (they look rather like those of SiO2- the structures are similar).
Those mess it up a bit as a refractory.

If you want to try it, I'd suggest trying oxalic acid instead. There's less carbon to burn off, and more oxygen in the molecule so you should get less charcoal.
If you don't care about the colour, conductivity and IR absorbance the citrate works fine.

I might have another go sometime, but use soaked cotton thread + see what I get.

aga - 5-11-2016 at 11:50

The Science comes later.

Right now it's all just Fun and making stuff to do some Science on.

Hard to science-up an over-toasted slice of bread by science alone.

For the Deep Science thinkers, please suggest some tests/experiments on these materials that will prod all this further than just Advanced Toast Burning !

I already did the I.N. number protocol for 'activated carbon' testing.

Morgan - 5-11-2016 at 14:00

Melba toast seems structurally sound, so maybe Melba toast would be something to try. If nothing else it might be a convenient path to thin carbon foam.

"Because Melba toast was such a hard toast, it was often given to infants as teething biscuits."
http://www.nationaldaycalendar.com/national-melba-toast-day-...

TheAlchemistPirate - 5-11-2016 at 14:08

Success! I have managed to create smooth, electrically conductive carbon foam using my own homemade dough! This time I allowed the bread to cook longer as well.

A particular piece of bread produced a region of a very "graphite-like" substance, which had a resistance of a few hundred Ohms when the test leads were 2 cm apart! (in some regions)

Resistance of one part of the chunk- http://imgur.com/1pcSKy1 (89,200 Ohms)

Resistance of another part- http://imgur.com/oEzDIdo (3,350 Ohms)

(I couldn't find the hundred Ohm regions again)

I will soon attempt to coat this material in copper metal. Also, the more conductive parts of the chunk did arc amazingly in a microwave oven.

[Edited on 5-11-2016 by TheAlchemistPirate]

Jstuyfzand - 5-11-2016 at 15:02

I wonder if the time you let it cook and the conductivity are related...

aga - 6-11-2016 at 01:23

Quote: Originally posted by TheAlchemistPirate

Success! I have managed to create smooth, electrically conductive carbon foam using my own homemade dough!

Nice one !

Resistance testing is a good idea.

Tried it on my remaining lump and got 30~40 ohms over 20mm !

Making an electrical connection is a bit hit-and-miss. Might be better to rig up some kind of wire pads for the probes, like q-tip sized balls of wire wool.

Didn't realise it was quite hard to cut with a hacksaw - must have a been a lot of work there violet sin.

violet sin - 6-11-2016 at 03:10

Super quick attempt to plate Ni across a chunk this afternoon failed. Power source AC plug was 12v 2A rated wall wart type, too high V. Couldnt find Ni rod so used MMO counter electrode which worked fine. Multmeter tests for resistance were not measured as everything was basicaly nonconductive before hand. Maybe need a hotter temp for longer, SS cup shields it too much? anyhow the Ni plated out as a redish sponge that barely crawled across the bit, not adhering at all. Work on the next powersupply was interrupted mid step and needed soldering, meaning more set up time instead of making a couple rough conections.

Regardless I set drained electroplating bits in the bottom of the next run. With random trimmings and the next chunk of bread(sourdough). Which was also doused with some plating solution prior to sealing. Hopefully the Ni sulfamate will decompose on the framework increasing initial conductivity. And the second run on last product may harden it more/increase conductivity. Some was doped with plating sol. and some was nontreated. So I should have some tests to do time permitting. Nap time flys by, hard to get much done project wise before obligations call.

Several different samples of ground cherry flower skeletons are cooking also. Use of three short SS tubes was employed. Samples were either chopped up and mixed, flattened then wrapped around a cylinder, wadded in a cone inside a cylinder or a few whole. Fire doesnt seem as hot tonight, so doing it for longer. Kinda roasted the front room last night temp wise.

Mine wasnt particularly hard to cut with a hacksaw. Far more resistant than I would have thought, but still nothing physically difficult.

wg48 - 6-11-2016 at 04:00

If the bread is very dry before carbonization does it still distort durring carbonization.

If your trying an initial electroplate you can make a crude Hull cell by angling the counter electrode so that the distance between it and the substrate varies. That will vary the current density across the substate. Low conductivity of the substrate may have a similar effect. It may give an indication of the correct current density to get the type of plating you require.

[Edited on 6-11-2016 by wg48]

wg48 - 6-11-2016 at 04:53

Quote: Originally posted by unionised

Apparently aluminium acid phosphates solutions are used as a ceramic binder. In particular with alumina ceramics in which it slowly chemicaly combins with the alumina to form various phosphates. According to the link below the service temperature is only about 1000C

https://books.google.co.uk/books?id=GPyI96S48PAC&pg=PA12...

That may be how castable ceramics are formulated as oposed to using cement like hydration reactions that reverse at temperature.

Morgan - 6-11-2016 at 06:10

I was thinking bolete mushrooms would be a hopeful try at carbonizing because of the many dense little pores but here they are toying with another kind of fungus for electrodes.
https://commons.wikimedia.org/wiki/File:Tyromyces_fissilis_9...
http://mycoweb-sae.narod.ru/fungi/Js/Photo_show.html?&.....

"Carbon fibers derived from a sustainable source, a type of wild mushroom, and modified with nanoparticles have been shown to outperform conventional graphite electrodes for lithium-ion batteries."
http://phys.org/news/2016-04-cook-battery-anodes-wild-mushro...

BOD513 - 6-11-2016 at 12:41

Soaking the bread in a ferric chloride solution before carbonizing it would probably increase the degree of graphitization, and you could then just wash the iron ii,iii oxide off with hcl. This might make electroplating it easier.

violet sin - 6-11-2016 at 12:56

Morgan,.. I know this guy... Aka me, who has been slaying the boletes

had the same though a few days ago, but didn't post it cause figured it was getting ahead of my self.

aga - 6-11-2016 at 12:58

Quote: Originally posted by Morgan

I was thinking bolete mushrooms would be a hopeful try at carbonizing because of the many dense little pores ...

Tinfoil, fire, find out, tell us the results.

Is there any human alive who has lost the ability to make Fire ?

unionised - 6-11-2016 at 13:56

Quote: Originally posted by aga

Is there any human alive who has lost the ability to make Fire ?

I suspect I know some who would have to Google it.
I wonder what other food would work.
Does fried bread work?

Incidentally, on a vaguely related note, you can mix soft wax into fire cement and end up with an "emulsion" of sorts, from which you can burn out the wax to leave a porous refractory.

Morgan - 6-11-2016 at 17:10

I've some meter long quartz tubes with a mere 19 mm inside diameter/25 mm o.d. that I don't mind trashing but I'm trying to figure out what to stuff them with because I can blowtorch the quartz glowing red hot without damage. It's just deciding how to form some material so that it doesn't stick to the sides. Maybe something a few millimeters smaller in diameter, perhaps plug the ends with foil and I don't have any inert gases. Also if I cored the material some sort of carbon foam tube could be made, again if I can get around the potential sticking or bonding to the coring rod if used and the quartz tube. The coring rod would probably prevent deformation to some extent. One other thought comes to mind using this technique, just some free association going on. Probably would need some fine tuning to have a chance.
https://www.youtube.com/watch?v=g4ph-h7l_aM

Aga, I know how you feel about doing experiments. I'm the same way really, if you want to know something the best way is to try it, and it's not only that but you discover lots of other things in the process, and better ways of doing things. And when the mood hits, there's nothing more fun than experimenting.

Violet sin, I'm glad someone else saw a potential in boletes, because I felt I was going out on a limb posting the thought. Some kinds of bracket fungi you find might be something to try. Another odd material maybe just to toy with ... http://www.ecovativedesign.com/myco-foam

Lastly, if I just wanted to make a light carbon tube maybe something along these lines would do if carbonized and starting with a fluffier pasta material.
http://hungry-4-more.com/wp-content/uploads/2009/06/dscn0510...
http://www.pastagarofalo.it/cms/uploads/product/ziti_linghi_...

[Edited on 7-11-2016 by Morgan]

j_sum1 - 6-11-2016 at 17:52

Oh to have some metre long quartz tubes. Nice.
If the concern is material sticking to the sides, I think that is easily remedied. I would wrap a slug of material that I was charring with paper. When done you can push the whole thing out and little should remain. Nothing that cannot be cleaned anyway.

As for an inert gas, I think CO2 is inert enough in this case. perhaps drop some dry ice in when you charge the tube and allow the sublimation to displace any air.
A nice advantage of the setup you propose is that you can potentially prepare several different samples at the same time.

Morgan - 6-11-2016 at 18:13

Yes, maybe something like parchment paper would do the trick to prevent sticking to the sides. Good suggestion.

j_sum1 - 6-11-2016 at 21:32

I am going to retract something I said before. I indicated that I would write something up for the wiki on this process. However this topic is exploding a bit. There are at least four different lines of interest: each seeking to optimise for different things and each with its own potential line of inquiry. I think it would be premature for me to write anything at this stage. We have

refractory applications -- in which case the task is to optimise structural integrity and strength, minimise deformation or include a shaping process, and minimise thermal conductivity.
a source of activated charcoal -- maximising surface area and hence absorbance is the goal here.
substrate for catalysis -- suggestions have been floated on how to incorporate a catalyst into the structure while maximising surface area.
use as electrodes -- here, electrical conductivity is the goal with some structural requirements and requirements for electrical connections as well as durability in service.

On top of this are proposed a few different schemes for making/obtaining bread for the task, suggestions of alternate starting materials (mushrooms) and a couple of different schemes and apparatus for pyrolising.

This looks to be a very fruitful area of study. Kind of exciting really. And new ideas are emerging faster than they can be tested. You gotta love the collaborative amateur scientific approach!

aga - 7-11-2016 at 08:20

Catalytic reaction converting CO₂ directly to ethanol ?

Now we're talking business.

https://www.ornl.gov/news/nano-spike-catalysts-convert-carbo...

Morgan - 7-11-2016 at 09:29

It sure would be nice to have a kiln to do some of these experiments. Here's some metal containers I bought in the past that might be suitable for carbon foam but probably there're lots of things you could get by with using. Here's some I thought about.

These are ~4.5 inch diameter threaded steel jars from a government agency in Colorado that were used for training of collecting radioactive materials. There's a reed valve I was thinking about installing that didn't come with them but they also have a 4-way steel insert that divides the jar. Maybe I could use the insert to separate some samples.
http://www.pulse-jets.com/phpbb3/download/file.php?id=8066
I drilled a hole in the lid of one of them.
http://www.pulse-jets.com/phpbb3/download/file.php?id=8068
Then there's these tri clover pint-sized jars made of 316 steel. I'm not sure what the larger filter thing is but I bought it on eBay because it looked like something I could use.
http://www.pulse-jets.com/phpbb3/download/file.php?id=7946
The jars have a Teflon gasket and you can instead of using the metal cap clamp two jars together. I just wonder how much pressure they would hold safely?
http://www.pulse-jets.com/phpbb3/download/file.php?id=14221&...
Some other perspectives if anyone has any other good uses for these things.
http://www.pulse-jets.com/phpbb3/download/file.php?id=14209&...
One with a ferrule fitting instead of a cap.
http://www.pulse-jets.com/phpbb3/download/file.php?id=2139
This long middle piece is some 3 inch pipe I could cap and clamp at both ends, maybe good for some French bread carbon foam shapes.
http://www.pulse-jets.com/phpbb3/download/file.php?id=9199
Some steel water bottles inverted and stuffed inside the heavy steel tri clover jars.
http://www.pulse-jets.com/phpbb3/download/file.php?id=14210&...

Here's a rough cut high temperature gray gasket meterial I cut out and a piece of capillary copper tubing that was an attempt to seal or press-fit into the half grove of the lid and jar where they meet. I didn't cut the tubing quite long enough as you can see but it was just an idea and I have lots of tubing. The Teflon gasket is nice but not good for high heat.
http://www.pulse-jets.com/phpbb3/download/file.php?id=2150

There's these Vollrath jars I found that are for kitchen use, maybe to hold cream or sugar. There's one with a lid on the bottom right in this photo.
http://www.pulse-jets.com/phpbb3/download/file.php?id=5258
http://www.pulse-jets.com/phpbb3/download/file.php?id=2035

I was thinking maybe even a large coffee can with the top cut with one of those can openers that makes the nice edge where you can set the lid back on and it fits nicely. They also aren't coated inside like some cans. Then maybe wrap aluminum foil over the can using the 19 inch sheets. Probably there are better/easier ideas if dwelled on.

unionised - 7-11-2016 at 11:50

Quote: Originally posted by j_sum1

As for an inert gas, I think CO2 is inert enough in this case.

I don't
C + CO₂ --> 2 CO

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