[meteorite-list] Big-Ass Purple Campo

From: Bob Martino <martino.6_at_meteoritecentral.com>
Date: Thu Apr 22 10:23:50 2004
Message-ID: <002001c2f0a0$f5ee1650$0300000a_at_TheMonolith>

All,

And now for an update on the Big-Ass Campo formerly known as "Rusty."

As you may recall (those who care, anyway), I bought a 19-pound Campo at the
Tucson 2003 show this year. No "New Campo" this, it was definitely an
Old-School specimen. Totally covered in rust.

I contacted Bill Mason and bought one of his new Meteorite Treatment Kits.
Unfortunately, I've had mixed results with it.

Yes, the rust-eating acid worked very well indeed. Unfortunately, the
instructions included with the kit left a bit to be desired. In one place
they say to neutralize the acid next, then soak it in alcohol. In another
place, it wrongly states to soak in alcohol first and _then_ use the acid
neutralizer. (Guess which instructions I followed.) I also followed the
instruction set which didn't happen to mention that the acid neutralizer
needs to be diluted with water first (In one place the instructions say
dilute 10:1 with water, and in another it says 20:1). The result was a
sticky meteorite with way too much neutralizer on it. Thus, when the oven
baking was in progress, my house was filled with a nasty burning chemical
stink. The heat also apparently destroyed the neutralizer chemicals, leaving
me with an ugly white deposit on the specimen (The fact that the cat grew
another head is probably just a coincidence).

So I went back and re-did the whole thing. At least the acid treatment went
fast because most of the rust was already gone. I also took the time to work
over my 4-inch long Nantan with the rust remover (It's now a nice 2-inch
long Nantan). I got the order of treatment and the concentration of
chemicals correct this time, I think.

Everything went well until the final coating with the spray-on sealant. Now,
my Nantan and my Campo are purple.

I can think of perhaps three reasons for this:

(1) I left the two specimens in the sun all day to dry & cure the spray
coating. Did a chemical/color change occur because of light, heat, or both?
(2) Perhaps the acid neutralizer was still too concentrated. There may have
been a reaction between the neutralizer and the spray-on coating.
(3) Perhaps the spray-on coating is simply too thick. I used four coats. The
instructions _did_ say "spray on more layers to add mil thickness," but then
again, they failed me before.

There is nothing in the instructions warning about Purple Haze or how to
avoid it.

Has anyone else have this problem?

So now I'm faced with removing the coating with acetone and trying yet
again. I'm also wondering how the acetone will affect the special
rust-inhibiting chemicals applied to the specimen by the various treatment
steps. Will I have to start all over again, or can I just spray on a new
coating and not worry? More important, how do I prevent the Purple Haze from
returning?

-----
Bob Martino, Tucson, AZ

Can you really name a star? Read the Truth!
http://home.columbus.rr.com/starfaq/
.
Received on Sat 22 Mar 2003 01:29:17 PM PST