Burnishing

I learned  to work with ACS by myself and with some books (no classes available in my area). I find very useful informations about almost everything I need except about the busnishing process.   If I use a metal or agathe busnisher, how much pressure do I have to use ? For how long ? Something else I should know ?

[Metalman]

Generally you can use a fair amount of pressure when you burnish.  I use those rubber blocks [R&T#69-124] to support the work.  As I think about it, I gueass i use a gentle pressure at first to get the surface brightening up and then I go over it a couple of times - harder and harder.
This is after firing - I am working the metal.

Now you can burnish before you fire to refine the surface - this is a good thing to do but you must be much more gentle with the unfired Art Clay Materials.
Hope this helps - let me know