I was requested to make a mokume ring for a ring and what I’ve
found is nirtic acid is recomended for etching the surface to
give the diferent colors more distinction. A satin finish
helps, but…
I also have a chunk of iron meteorite(sic?) and once I’ve heated
it up I’m afraid that I’ll ruin the nice texture. But I know the
texture or finish can be re-applied, or etched with nitric acid.
Hi Calvin,
First of all, DON’T heat the meteorite! You’ll spoil the
texture, and it cannot be restored. These texture, which is
actually a grain etching of the structure of the iron - nickle
composition called Widmanstetter’s figures, has taken several
million years to form (1 million years per 100 C cooling down).
The metal then consists of two types of crystals, one with much
nickle alloyed with iron, one with very little nickle. These two
alloys react to the etching in different ways, thus showing the
figure. Heating up means changing the structure of the metal -
adios figure.
For etching, I have used a 5% solution of nitric acid in
ethanol, as a solution in water can result in brown splots from
troilite inclusions. You can cut, saw, turn, file, sand the
meteorite, as long as no heat builds up.
Regarding nitric acid, be careful, best buy ready solution, as
the concentrated stuff is very harmful. The fumes that come off
it enter your lungs and become acid again. There has been a
death reported of a student working night shift in a factory
where brass parts were produced. They used a mix containing
nitric to pickle the parts. A pot dipped over and all the acid
was spilled on the floor. So far no great danger - but the young
man used a rag to clean up. This (organic stuff + nitric acid)
resulted in NOXes gasing off. He was dead some hours later, and
there could have nothing been to help him. The fumes from
concentrated nitric acid can react with organic matter nearby so
spontaneous combustion can set in. So be careful, Markus