[meteorite-list] dronino (in)stability: a solution ?

From: Zelimir Gabelica <Z.Gabelica_at_meteoritecentral.com>
Date: Thu Apr 22 10:29:56 2004
Message-ID: <1.5.4.32.20030916162121.007032b8_at_pop.univ-mulhouse.fr>

Hello Steve, Matteo, List,

Dronino seems to be very versatile to rusting indeed.=20
-I got a small slice from Sergey Vasiliev in May 2003 with not any rust
problem so far (now about 4 months after).=20
-I purchesed 2 other slices in Ensisheim (June 21) from Serguei (Serge)
Afanasiev and one month after they both were fully covered with rust,
basically all around the silicate inclusions.
- I purchased another small slice from Vasiliev in Ensisheim and today it is
just as fresh as in June....
=20
Apparently either every Dronino piece is intrinsicaly different or it is a
problem of cutting method and precautions taken after cutting, but probably
not a storage problem because all the 4 slices were stored in the very same
drawers and boxes, with just, as (poor) protection, a silica bag in between
the cotton wool and the plastic box bottom.

Having nothing to loose with Serge's slices and not having on hand any
reliable recipe nor chemicals, I directly tried the first commercial product
I found in a Department Store (in Belgium).=20
It is a tube of compact (wax-like) "paste" named "STRAHLDUR" (German brand
?) sold for a few euros as a "mirror finish without polishing" for current
domestic houseworks...

Operatory conditions, as written on the tube and box, in 6 languages (also
in italian, Matteo!), suggest to "apply Strahldur" on a WET sponge for
"stainless steel, copper, brass, tin, chromium, aluminum, but also plastics,
enamel, glass, tiles bathroom fittings, sink, hot-plates, oven grill,
toaster, kettle, IRON, cutlery, resopal kitchen furniture, refrigerators,
window frames, garden furniture, and much much more"...moreover: "it removes
RUST from chrom plated parts and dirt from wheel rims"...
It so continues:
"Wash the object (with a wet sponge) and dry (wipe off)...ready!"...
Any warnings ? Not really. They write: "Strahldur contains NO ACID and is
gentle to the skin"...
Composition ? "contains "mineral polish" (?), emulsified paraffin, natural
soap, "cleansing raw materials" (?)...and a "fresh orange fragrance"
(probably to remove tha latest doubts of a semi-convinced housewife"...).

As a chemist, I realized that the paste could prove relatively harmful to
most of metallic objects. And the metals cited above (including rust!) can
mostly be involved in a meteorite as well!
Without preliminary trials on any other meteorite, I just then removed most
of the superficial rust from my 2 dirty Droninos with a razor blade (dry
conditions) and then applied Strahldur with a DRY cloth (I IGNORED wetting
for obvious reasons) for about 2 minutes, by gently rubbing all around the
slices. Then just gently polished with another soft cloth so as to recover
the initial mirror-brillant polish.
The slices immediately recovered their initial aspect and were mint again!

This treatment was performed 5 weeks ago and I just checked the 2 slices
today: perfect with not any trace of rust! (remember that rust appeared 1
month after purchase of the mint slices).

This can be a first step towards a solution of rust removing from our
polished iron slices and, in particular, Dronino.
 I am however cautious and prefer waiting for more time but so far this kind
of simple treatment appears fairly promising.=20
I will, of course, keep you informed. But the message here can be that,
instead of using complicated and harm chemicals (such as preliminary I
wanted to use in a laboratory), it is perhaps preferable to put our faith
into very common cleaning products for housewifes. They are, by definition,
not dengerous, must be efficient and, especially, polyvalent, thus for a lot
if different uses, probably including meteorite cleaning, rust removing and,
possibly, further protecting through some film (my speculation).

I almost forgot.
 I further tried this product to remove some rust spots from an etched iron
involving Widmannst=E4tten pattern.=20
As all my Gibeons are "desperatly" stable, I tried to treat a slice of
SPEARMAN (Om IIIAB, Texas). Rust was immediately gone but the W pattern
remained untouched!=20
This is (for me) an even more promising result as it was always a nightmare
for me to have to remove rust from a slice through some chemical (acid) and
then re-treat with Nitol (or FeCl3) to recover the W pattern.

Glad if this helps and happy to answer any further question or comment,

All the best,

Zelimir


------
At 04:51 16/09/03 -0700, Steve Arnold wrote:
>Hello again list.Could someone please let me know how stable the DRONINO=20
>meteorite is?I mean versus campo, nantan, and some other iron pieces.I am
>trying to decide whether or not to buy some.I, like mike blood like to
>collect only stone or stoney-irons, but like to take a chance on a good
>stable iron piece.Let me know.

> steve arnold
------
On Tue, 16 Sep 2003 04:58:39 -0700 (PDT), Matteo answered:

Hello

Dronino have high problem with rust, I am under search
a method for stop this.
Regards

Matteo
******************************************************
Prof. Zelimir Gabelica
Groupe S=E9curit=E9 et Ecologie Chimiques (GSEC) - ENSCMu
3, rue A. Werner
F-68093 MULHOUSE Cedex, FRANCE
Tel: +33 (0)3 89 33 68 94
FAX: +33 (0)3 89 33 68 15
e-Mail: Z.Gabelica_at_uha.fr
******************************************************
Received on Tue 16 Sep 2003 12:21:21 PM PDT