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Etching an Iron Meteorite - Do's and Don'ts!

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#1 Glassthrower

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Posted 05 April 2008 - 10:42 AM

Etching an iron meteorite is an art and a science. It requires careful polishing of the surface in preparation of the etching process. The process itself involves one of two dangerous chemicals - nitric acid or nitol. Both of these should be used with thick rubber gloves and a respirator in a well-ventilated area. Both will eat human skin and lung tissue.

Having said that, please watch the following series of videos. These videos show huge slabs of Seymchan pallasite (iron siderite parts) being etched by Russians in a garage-type facility. Everything you should NOT do is present in this video. I respect the Russians' enthusiasm for the project, but I have to wonder if these people are still alive and in good health. Handling nitol/nitric in this manner is VERY DANGEROUS.

DO NOT ATTEMPT ETCHING USING THE TECHNIQUES SHOWN IN THE RUSSIAN VIDEOS!

http://etching-meteo...n.blogspot.com/

Now, having seen this potentially-disastrous method of etching, let's witness how it is properly done :

http://www.youtube.c...h?v=_Tmi5qZgIFQ

Notice Mr. Meteorite's careful handling of the slab in the bath - he moves it slowly and gently to avoid splashing the acid. He uses rubber gloves. Given the relatively small amount of nitric/nitol he is using, one could forgo the respirator assuming the room is well-ventilated.

Good luck and clear falling skies!

#2 molniyabeer

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Posted 05 April 2008 - 01:17 PM

Mike,

That Russian clip is truly frightning! You have to wonder what kind of damage that's doing to their skin and lungs.

The second clip is interesting but leaves out two key things. First, he does not identify his etching sollution (I know there are a couple of options there) and he also does not say how he gets all the ATF off the slice afterward (just lots of paper towels?).

Have you etched any irons and, if so, where do you get your chemicals?

Cheers,

#3 Glassthrower

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Posted 05 April 2008 - 01:50 PM

Hi Steve,

I got your PM, but I thought a public answer might help out some others as well.

I have yet to etch my own meteorite. I am keenly interested in the process and would like to try it, but I just don't have the time and place to do it now. So I watch, read and learn about it, but don't dare try it yet.

I do know of a couple of people who etch meteorites, but I have not used their services personally and I don't know what they charge for it. I'll check around today and see if I can scare up an "etcher" who has good references, a good "portfolio" of etches to show, and will do it for a reasonable price. I'll get back to you and let you know what I find out.

Watching those Russian videos give me chills.

Referencing H.H. Nininger's "Out of the Sky", I'll sum up what Nininger says about etching solutions :

Nitric acid is used in an aqueous solution that is 6% nitric acid. Stronger or weaker solutions can be used, depending on the meteorite and the type of etch desired.

Nitol is a solution of concentrated nitric acid and alcohol. It more readily attacks the skin than the aqueous solution does. If the Russians are using nitol, it's safe to assume they have no skin left on their hands. So either these etchers are skinless masochists, or they are using the aqueous solution. Either way, aqueous or not, they should be using gloves. And that dark, dank, small enclosed area does not look well ventilated.

At any rate, back to what Nininger says on etching solutions (pp. 130-131) - he says other chemicals have been used to etch, but they are inferior to nitric acid and nitol in several ways he does not specifically mention. The chemicals he mentions as being inferior are Bichloride of Mercury, Bromine Water, Picric Acid, and Hydrochloric Acid.

Given that nitric acid can be used to manufacture powerful explosives, I would imagine it is not easily acquired in today's post-911 world. Where the etchers get this stuff, I don't know. I never really looked into it, because I had no immediate plans to start etching.

Clear falling skies,

MikeG

#4 Shmals

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Posted 06 April 2008 - 11:14 PM

I love how he uses his bare hands during the process, then nearly drops the thing after all that work, followed by him wiping his face right after handling the chemicals... with that being said they do have one GIANT meteorite slice there! :bigshock:

#5 Glassthrower

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Posted 07 April 2008 - 12:32 AM

Yeah, did you see how he had to manhandle that thing around?! :lol:

Meteoritic iron is very HEAVY and I bet that slab weighed a couple of hundred pounds. No wonder he had to "walk it" into position on that grating where he was pouring the acid/nitol.

IMO, if the weather permitted, such an operation should be done OUTSIDE in the open air where ventilation is not an issue at all. Protective gloves should be worn and protective goggles/glasses as well - just in case some of the acid were to splash. It probably wouldn't hurt to wear a rubberized butcher's apron.

Regards,

MikeG

#6 upsguy

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Posted 07 April 2008 - 02:08 AM

Yeah, that acid there looked mighty hot! Wonder why the dude hadn't cried out in anguish?! :question:

Has anyone ever seen/heard of an iron slab, like the one in the video? How much $ would something that size cost? :question:

#7 molniyabeer

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Posted 07 April 2008 - 09:00 AM

Jim,

I think that falls into the "if you have to ask..." category!

#8 Glassthrower

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Posted 07 April 2008 - 09:17 AM

Wonder why the dude hadn't cried out in anguish?!


He's an alien mutant from the acid-world Canopus-4.

How much $ would something that size cost?


If you could travel over there to Russia and buy it directly from the source - probably less than you think and probably no more than a couple of hundred dollars.

On this side of pond, after middlemen make their profit and the retailer puts his price tag on it - thousands.

Regards,

MikeG

#9 Jim7728

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Posted 07 April 2008 - 10:37 PM

Mike, that was very interesting!

The use of transmission fluid was as a sealer was surprising but did make sense.

#10 Glassthrower

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Posted 08 April 2008 - 12:43 AM

Well, I don't know if I would personally use transmission fluid - I have heard/seen this several times, but it varies from person to person.

A couple of things to keep in mind with irons, especially those which are especially prone to rust or will be stored in a humid clime :

1) anything like WD-40, Sheath, transmission fluid, or even mineral oil will retard oxidation, but it will also penetrate the meteorite, in essence "contaminating" it. This is not a big deal with a classified iron like Sikhote Alin or Canyon Diablo - we know what it is, it's not going to be lab analyzed, and the presence of Earthly chemicals will not throw off any tests. Also bear in mind that these kinds of treatments leave their own mark - an iron meteorite treated in WD-40 or tranny fluid will always smell like WD-40 or tranny fluid, and may have an oily feel to it. This doesn't bother some people.

2) The alternative to treating your irons with a protectant chemical is to prevent rust from happening in the first place. This is akin to cleaning optics : instead of worrying about which brand of lens cleaning solution is best, just don't let the lens get dirty in the first place. The key is to purge any remnant moisture in the meteorite by treating it in 99% alcohol bath to chase out water, pat dry, and then bake the specimen in the oven at about 200-250 degrees for several hours to completely purge the meteorite of all water. After this, some people choose to "treat" the meteorite with an oil protectant, or seal it with a lacquer-type coat. Purging of the water should always be done before sealing or clear-coating. (don't seal in trapped water!) If you choose not to chemically-treat, then take your clean purged irons and store them in a sealed airtight container like tupperware. Place a packet of dessicant in the storage container to absorb residual moisture from the surrounding air. Handle the specimen as little as possible, wipe it clean with a microfibre cloth and then place it back in the dry storage container.

3) if it's a big centerpiece or display iron, then your best bet is to purge by alcohol and heat (if necessary) and then treat/seal it with something. You may get away with not sealing it if you live in the desert southwest, but displaying any iron in a humid environment warrants some kind of protection.

Regards and clear falling skies!

MikeG

#11 Jim7728

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Posted 08 April 2008 - 05:38 PM

Thanks again Mike! :)

Great information! :bow:

BTW, I don't think I was going to go the tranny fluid route with my incoming sample. ;) :jump:






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