Archaeologica.org

Rocket,

It would take the same time (or maybe less) than the time it would take for "regular" forced air smelting using charcoal, since both need constant forced air feed. All high-temp smelting (sort of an oxy-moron) required forced air, so it is not really a stretch to add olive oil to the air to make an oil/air mist. Young apprentices and slaves are useful for this task.

Every used cooking spray? Try a simple experiment: next time you fire up the barbi, use it on the coals. When you get out of the hospital, come back and tell us what a great big fire you had, with so little effort.

come back and tell us what a great big fire you had, with so little effort.

Olive oil based cooking sprays work wonderfully for that!

From the article cited by forester:

Tests carried out by the Italian Institute of Technologies Applied to Cultural Heritage, for whom Belgiorno works, have discovered olive oil residues in ovens on the site.

That sounds like proof to me.

But, "just to add fuel to the fire," I don't believe they used people to aerosolize oil directly into the flames. They would have collapsed from being out of breath, been burnt to a crisp, or died from inhaling fumes.

And another note, wood burning at high temperatures doesn't leave any ash.

From Realscience: Ancient Copper

To make fires hot enough to vitrify copper slag would have required vast amounts of wood. In fact, Lehner found that the floors of the site were covered with very deep, thick velvet carbon ash from the burnt wood. Lehner said that the cutting of wood to produce such huge amounts of ash contributed to the deforestation of Egypt at the time when the pyramids were being built.

And...

To produce the very hot temperatures, metalworkers probably used long tubes to blow air into the molds. While no such tubes have been found at Legner’s site, relief art from a tomb in Sakkara, which was built at about the same time as the pyramids, shows metalworkers blowing through tubes to produce a hotter fire.

You've almost won me over, Andy. But not quite yet. The theory sounds compelling, but the proof of the pudding is in the eating. So I'd still like to see a viable copper smelting process – with tube-blown aerosolized olive oil – actually replicated resulting in a copper utensil produced.
Forgive me for holding out until then.

Well, you are going to have a long wait, since I am not in the smelting business. No apprentice or slaves, you see. Feel free to try it yourself, though. I recommend high-octane extra virgin olive oil.

Forester wrote:Well, you are going to have a long wait, since I am not in the smelting business. Feel free to try it yourself, though. I recommend high-octane extra virgin olive oil.

Virgin? I'm on it! Don't move!
I'll run to the store first thing monday!
(Please send your postcards to the National Burn Unit, 4th floor, IC Ward 17 "The Fridge")

Good exchange!

Sounds like something the 'Mythbusters' should take on!

Hey...can anyone read ancient egyptian here?...the ancient illustrations shows them blowing through tubes but does it say anything about atomized olive oil? I have seen copper smelting using the tube blowing method for charcoal (to get more oxygen to the fire). I am still totally mystified how they could smelt without any charcoal as a medium for burning. To sustain a flame you would need an atomizing olive oil fuel injector. I am not sure this would even work. Remember we are not talking about conditions under pressure like in a car's engine here. I am as yet at a loss. Wish we had more info from the dig itself about this question.

Hey...can anyone read ancient egyptian here?...the ancient illustrations shows them blowing through tubes but does it say anything about atomized olive oil?

I never said ancient Egyptians blew olive oil throught tubes. I posted that particular link to illustrate that they did in fact use long tubes to force air into the copper smelters, and that contrary to what one poster said, residual ash would be found for temperatures required for copper smelting if wood/charcoal were used. Read the whole thread. The issues here are:

1. As per the header story, early Crete people seem to have used olive oil as fuel for copper smelting, instead of the expected charcoal used in other places (such as Egypt)

2. Some members questioned whether olive oil could have even been used as fuel, instead of charcoal or wood.

3. I described a possible way olive oil could be used. It was my idea only. I do not think that you need any kind of "atomizing olive oil fuel injector." No, we are not "talking about conditions under pressure like in a car's engine here." Some oil blown through some long tubes as a spray may suffice, with nothing more than lung power, and provided the tube is long enough, it could be done without burning the blower.

4. Yes, I also wish there were some more info on the dig. I am simply throwing out ideas and having fun speculating about how it could have been done, given the constraints and available technology involved. Any alternative ideas would be welcome. How do you think olive oil might have been used as a fuel for copper smelting?

above Guest = Forester.

I was being light about the reading egyptian thing there...please dont take it wrong at all.

I do wonder about the atomized olive oil. In theory this could provide a good fuel/air ratio. My concern is that this might produce a puff of flame, but how would the olive oil being blown in by lung power be able to sustain a flame in discrete puffs? I brought up a fuel injector sort of idea as an illustration of a steady stream of atomized olive oil delivery system. Just wondering how that could be accomplished.

My guess is we are missing some critical piece of information here (probably just left out of the article) that would clear the whole thing up. It could even be something as simple as the writer of the article used the word "charcoal" when what was really meant was "coal". It could all be something as simple as that, right?

Forester, you have really done your homework!
My hypothesizing has been met by your scholarly findings.

Just to clear up where I was coming from. If you fire ceramics at 2300 degrees farenheit using a "groundhog" kiln, a very powerful draft is created, and the wood is virtually vaporized, and I suppose any remaining ash is carried out. (Some fly ash sticks to the pots). At the end of the process, when you look inside the kiln it looks clean of ash. (I suppose there may be small traces. And if you check the areas around kilns you no doubt find wood scraps and piles of unused fuel! Hard to believe the archeologists coulld actuly find residue of olive oil in the ovens!)

But you wouldn't find the thick layers of ash that the archaeologists found. So the Egyptians were clearly using a different process that did, indeed, leave ashes, and which I did not understand.
I was impressed to learn that they used blowing tubes!
But, going back to the groundhog kiln technology, the draft increases as
the temperature rises, and you don't need bellows or any forced air. THe heat draws the oxygen through the burning fuel. This technique might have lowered the death rate among assistant copper smelters!
However, there may be many reasons why it would not have worked.)
This is what I was thinking of before reading all your posts.

My guess is we are missing some critical piece of information here (probably just left out of the article) that would clear the whole thing up. It could even be something as simple as the writer of the article used the word "charcoal" when what was really meant was "coal". It could all be something as simple as that, right?

Yes, this is like an equation O + M = C in which O = olive oil and C = copper and the M= the mechanism for doing so.

We have evidence for the O and the C therefore one has to deduce the mechanism. The ancients were far more clever than we give them credit for and this would have been one of the major economic interests of the time, certainly the king would have been deeply interested in the production of metal!

The notion of the tube seems far-fetched at first glance but I have seen glass blowing demonstrated in Venice at comparable temperatures and the artists did not look as if their lips had been burned off.