[barrel browner]

I have been using Ferric chloride for many years as part of a metal finish, it used to look darker than it does now the modern stuff looks watery and works nowhere near as well.  A producer informed me that it is now made with mill scale and Ferrous sulphate.  If this is the case it is no good for what I need it for, can you still have it made the old way and how did they used to make it. I would be grateful for any advice / information.

[Borek]

the modern stuff looks watery

I suppose that means you buy a solution of ferric chloride, not the solid?

Do they give the concentration of the stuff? Has is changed?

[barrel browner]

Hi I have various strength solutions of Ferric old and new, the problem for me is with the new way it is made.

[Borek]

Depends on the point of view.

Technically it doesn't matter how the material that works OK was made, what matters is its exact composition. This in large part depends on the production method, no doubt about it, but in general you should be able to get the effect you need by using iron(III) chloride from any source, just with correct additivies.

Not that I know what they should be, what I am saying is that there is a chance you are asking a wrong question.

Most recipes I quickly googled (in Polish, so they probably won't be of any help to you) start with FeCl₃ but they call for numerous, different additives, like FeCl₂ or HgCl₂ - so for example could be the previous solution contained a different amount of Fe(II), which made it work better.