David wrote:

I tend to think they put some laquer on the pipe at production to keep
it shiny. I do outdoor sculpture with copper and first use fine steel
wool to get down to bare metal, chemically clean with good old malt
vinegar (how people use that stuff as food flavouring !) and then with
a bit of practice apply a cupric nitrate solution. Hey presto 3 years
worth of patination in an hour. If you want to keep it a plain old
brown just apply some wax to keep the acid rain away.


What is the stuff that make it stink of rotten eggs and turns it black?
Presumably a sulphite of some sort?

OI had mnoe of those 'copper picture' kits years ago. A layer of laquer
has kept if a good mixture of copper and black for years...