They also
used a drum, and the article described how they coated the drum
with the mixture of oxide and -something- with a normal painter brush, by
hand...
That -something- is mentioned in the article, I forgot what it was.
Yes, that -something-. That is what is the mystery.
The binder for a marine grade paint would probably work fine.
What is it? Some kind of durable acrylic?
Peace... Sridhar