Making lava at home

Ignoramus11448 fired this volley in news:rPidnaFM7Mvp_2XUnZ2dnUVZ snipped-for-privacy@giganews.com:

They're called "snakes". The ash doesn't much resemble lava, unless you stretch the analogy to "cooled lava" .

The "classic" volcano experiment uses ammonium dichromate crystals as the fuel. As it burns, it emits a fluffy greenish ash that cascades down the sides of the model.

Dichromates, in general, are not "friendly" chemicals. Combine virulent oxidizer properties (enough so to burn moist skin) with hexavalent (carcinogenic) chromium, and you have a true witch's brew.

LLoyd

They're called "Snakes". Any fireworks dealer is likely to have them.

These things?

All you need is Mercury(II) thiocyanate to make a really good one. About $200 for 250g from my favorite chemical supply house.

Can't you get some actual lava? I think they sell it in some places as a paving material in place of gravel.

Supposedly, it melts at a lower temperature than silica-based rock.

DB

Spehro Pefhany fired this volley in news: snipped-for-privacy@4ax.com:

Nah... That was very old, very dangerous technology (for the user, as well). Modern snakes are made from nitrated asphaltum.

LLoyd

We regularly make "lava" when we smelt iron from its ores, using medieval techniques. It is the slag from the process. (The iron doesn't actually turn to liquid in this process). We need temps of around 1100° C to get it to happen. Here, we are making wrought iron or sword steel, not cast iron, which takes a few hundred more degrees to get the iron itself to flow.

You won't get silica sand to melt with your forge, either at that temp. You probably can get used glass to melt, though, if you want to go that way. Or, you can melt used glass, then add silica sand to it and the whole thing may melt. I would be real concerned for safety. Mistakes with melted material at those temps can get out of hand real quick!

----Not that I'd totally avoid doing it, but try it out ahead of time with only adults in attendance.

I haven't looked around lately, but I seem to remember a grade school science experiment that made a sort of "lava" exit a table top volcano. The "lava" might have been bicarbonate of soda.

Pete Stanaitis

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Ignoramus23032 wrote:

Great. Now you've got this group on a government watch list for terrorists... Oh wait... We're already on the list. Never mind.

Personally, I think it's an opportunity for the guy to play with fire while he has the kids around but at a safe distance... I think a lot of us wish we had time / reason to do stuff like that.

All things said and considered, I will go and try to see if there really is slag for sale at the landscaping section of Home Depot, and will start with that if my memory was right.

i

Thermite? You would get molten iron which has lower viscosity than lava. There might be enough (UV) light to be dangerous.

Bernhard

I do have a jar of thermite.

It is too quick to burn, too hot, too scary, does not look like lava. It is fun in its own way.

i

Anyone who can actually make something is suspect. The rules are made by people who shuffle paper for a living.

I need one of these, I'm going to BBQ 180 Lbs of tri-tip next month

Iggy. All the rocks you will find in your area contain water that will turn to steam and explode when heated rapidly. Please use some of the actual lava rocks you wrote about and first heat them for an hour or more in a hot oven to drive the moisture out. May need to do this several times. Your local rocks are basalt and will take forever to get the water out. Exploding rocks are not funny! They are very dangerous.

Your 1800 degree forge will just get the rocks red. The will not melt. A quick Google search shows lava temperatures of 2200 degrees F.

I think the glass suggestion will be a better choice.

Paul

Even though you now seem to be headed towards glass/slag etc. I felt I should belatedly leap in an warn about using salt.

Two issues with salt.

One is for stuff in the workshop, A salt bath spits enough finely divided salt "smoke" into the air to make rust spots appear on steel objects all around the shop DAMHIKT.

The other is that when the salt melts it has about the same viscosity as water. This is a Really Bad Idea(tm) for lava making, although dead handy when used in a crucible for hardening steel.

The other, other point (ok, three) is that the salt fumes in an electric forge will destroy the protective oxide layer on the heating elements and lead to rapid failure. Luckily I just got all of the hardening job done before I discovered this...

Mark Rand RTFM

Karl, I have never seen sulfur for sale at drugstores, what would be a product that is sulfur?

i

You might be able to find it at a garden shop. It's sometimes used to reduce soil Ph.

I actually found out, it is used as dandruff medication.

i

On Wed, 29 Apr 2009 10:46:37 -0400, the infamous Spehro Pefhany scrawled the following:

That's it! Oh, hell. We can't urge him to use something which would put out something his (not my) president just branded the new deadly climate gas, CO2.

------------------------------------------------------ No matter how hard you try, you cannot baptize a cat. ----------------------------

Your kid is great.

But about the making of lava: you might just have to explain to him that your forge really isn't going to burn hot enough to make actual lava from most of the stone available. Get a DVD of the volcanic activity on Hawaii which should really interest him so that he can see how the planet works.

Then get a bag of cement mix and play around with that by making some wood molds and pouring that instead. Probably much safer (wear particle masks and eye protection) and he will have an end item to take to school for show and tell.

Or melt some aluminum in the forge and pour that explaining that the lower melt temp makes this a feasable route to go using your forge.

Just suggestions. Dave