K&Q electron miscroscopy preliminary results- facinating

[tom hansen]

Thanks again guys- here is another piece of information regarding our friend, the black pigment used in the paint on the cores. It is made of charred animal bones, which gives it the peaks of Calcium and Phosphorous.

Ivory Black: Bone Black. (PBk 9) The most commonly employed black pigment, it is made of carbon, calcium phosphate, and calcium carbonate, calcium sulfate, or other impurities. It has a brownish undertone as compared to the vine black series, but is cooler than Mars Black. Made by charring animal bones or (originally) ivory scraps which make it finer, more intense, and of a higher carbon content than bone. It is light and fluffy, but less so than Lamp Black. It takes up considerable oil in the grinding process (making it less suitable for underpainting), and it dries slowly, creating a soft, brittle film. It serves well as an all-around black and tinting color. It is the only member of the impure carbon group that is recommended as a permanent artist color. However, it is one of the worst pigments to use full strength or in nearly full strength as an undercoat in oil paintings: a film of any other pigment laid over straight ivory black is extremely likely to crack. It is probably better to use Mars Black for underpainting and Ivory black for glazing mixed with a fat medium to add flexibility.
Paris Black is an inferior grade of ivory black.
Lightfastness: I
Oil Absorption: Low
Oil Film: slow drying, soft, and brittle
Toxicity: Hazardous, do not breathe dust

[milsurp]

Thanks for spending your time and money to share this with us Tom, well done.

[Peter Wiking]

tom.
Would it work on other metals like zink and tombak ?

Thanks.
Peter

[Marc Garlasco]

Peter,
My thought EXACTLY! If so, well, I am calling all the engineering schools in NY tomorrow to get this set up for me...
Marc

[Brian S]

3. Frame RK- Here is a shocker- There is RHODIUM coating which accounts for the frosting, in contrast to previous views this was a myth.

Pieter and Stump trashed me when I spoke about this...

[Marc Garlasco]

Ah, but now you have PROOF!!!!

[Brian S]

Ah, but now you have PROOF!!!!

AYE MATEY

You're right Rich, but this a confusion thart exists as long as I collect.
A lot of people calling e.g. the white frosting on KC and Oacks (no restrikes of course) Rhodium frosting. This whithening is in fact the result of acid threatment.

Pieter.

I could play the "I told you so" game...

[tom hansen]

Craig- thanks and your welcome- I enjoyed doing it and it got me out of clinic for a morning. It was nice to have fun again being in a lab.


Oddly Brian, while in the lab the guy was puzzled about rhodium coating on the silver and so did a google search. What do you suppose came up? Old Brian on the WAF site getting toasted by Bill Stump for that very contention. The guy had a little chuckle about it. I have a photo of it- it is kind of funny.

[tom hansen]

Here is the SEM

[tom hansen]

in operation

[tom hansen]

Warren- the engineer

[tom hansen]

SEM again

[Dietrich Maerz]

Tom,

here's one of the prints you did send me. It's the RK-Frame and clearly shows the Rhodium content. You can for sure explain more.

Dietrich

[tom hansen]

Thanks Dietrich!



As far as the process goes, a beam of electrons activates material on the surface of the piece being analyzed, reflecting some of the electron beam and= causing some partial vaporization of the material (a very small amount) which allows the elemental analysis of the substance being analyzed as well as a VERY detailed picuture. The good thing about it is that it can analyze a very small spot, which will avoid contamination by any area which may have adjacent rust and to avoid areas of carbon accumulation or oxidation (patina).

[Brian S]

Brian's used to getting roasted by experts on this site.