Fireproof Carbon Foam From Pyrolysed Bread

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Introduction: Fireproof Carbon Foam From Pyrolysed Bread

Metal Contest 2016

Runner Up in the
Metal Contest 2016

Carbon foam has some very useful properties: It is an excellent thermal insulator.

The fact that it's made from bread adds "much wow!" to a very simple process.

You could conceivably cover you space rocket in these ablative tiles for re-entry. Because Science! NASA! Outer-space! Clickbait!

Step 1: Weld a Steel Box With a Hole in It

You'll need a container that you can heat the ever living tar out of. Literally, we are going to roast the tar out of bread.

The hole is so hot gas can escape and the box doesn't blow up and kill you.

I made my hole threaded so I could add a bolt and let only a tiny amount of gas out through the threads.

I also purged the box with Argon gas. A redundant step; but, belt and suspenders amirite?

I'd leave a chemistry joke here, but all the good ones argon.

Step 2: Roast the Box With a Propane Torch, or Campfire, Until No More Yellow Flames Are Visible

The yellow flames are hot volatile gasses leaving the box. Once the yellow flames die down, you know your bread has been turned to carbon foam.

Step 3: Much Fun! Experiments! So Enjoyment! Very Hyperbole!

I blast the carbon foam with an oxy/acetylene torch and melt aluminum directly on the tile.

Then I checked with a thermocouple how well the tile was insulating from the torch blast.

I also checked the electrical resistance. It is very high! From my previous tinkering with graphite, it has very low resistance. The difference is in the structure of the carbon! More research required...

I also made a vid of this. I'm told it sucks:

https://youtu.be/Wex_yKfrTo4

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68 Comments

I guess I'm missing something... I think I've made this more than a few times already... a couple of times in a toaster oven during a phone call... on a grill when a hamburger bun got left behind... Sorry but this is just burnt bread.... Why go to the trouble of making a steal box to burn it in, a gas grill or toaster oven will do it just as well... Or if you don't want the smells just put in in your oven when you turn the oven on the clean cycle.

Pyrolizing is the burning in the absence of Oxygen. The Argon doesn't make is special, but it DOES replace the oxygen in the chamber. The oxygen would be burned off pretty quickly in a sealed chamber, but in a toaster, the resupply would lead to a lot of CO2 (where the oxygen mixes with the Carbon in the burn down process) which is very different in behavior than CO2. So this LOOKS like burned bread, and it IS, but in the absence of Oxygen - so it is C, not CO2. "Brown's Gas" is the flammable byproduct that is giving the yellow flames mentioned. I hope that helps.

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Yeah, I don't think that's Brown's Gas - water that's been electrolyzed into hydrogen and oxygen is referred to by that name.

I have seen "Brown's Gas" referred to in other posts here, and am compelled to illuminate the error. The gas released in the pyrolization [sp?] process in this 'able has NO relation to Brown's Gas [a stoicametric mixture of Hydrogen and Oxygen resulting from the ELECTROLYSIS OF WATER!].

The gas produced by pyrolization IS NOT Brown's Gas!

Please forgive my misspellings; it's been over 40 years since my last chemistry class.

Yes! Thanks! I actually was aware of that, but had been reading about Brown's Gas around the time of the comment and was in a hurry and goofed! Thanks for catching it all this time later, johnny3h!

Science...if we are wrong, we admit it!

not the same thing, If you notice he used argon in the heating process, it changes the bread into something else entirely

I don't think it is any magic property of Argon in particular, as much as it is that it replaces the oxygen in the container. The paint can with the hole works because the outgassing of the bread and early burning likely burns out the oxygen and creates positive pressure keeping a sufficient amount out to cause the bread to burn with oxygen...same as making char cloth or biochar

Yes, its bread with everything but the carbon burned out of it, you could make it in a toaster or oven as well. AvE just likes going overkill ;)

How long will the foam/burnt toast will hold up under the high heat? I'm in the process of building an pizza oven and was wondering if this will work for insulating the dome. Thanks for the Instructable.

Well, I left some charcoal on top of a wood heater one year in a mortar (a ceramic bowl used for grinding). By the end of the winter the carbon that was ground into the ceramic had completely disappeared. The top of the heater stayed above 400 f for about 7 months.