The only way I have been able to get ferric chloride is to order it in the powder form..I have a pound coming..Does anyone know what they usual powder=water ratio is? What works best for you?

Firstly, add the FeCl TO the water, NOT the water TO the FeCl!
1 pound of Fecl to 1 pound of water. Use distilled water.
Now, that will give you what is called 42 Baume, which is a "strength" of solution.
This solution can then be mixed with distilled water at about 3:1 - H2O/FeCl for a good etching mix.

42 M actualy
(roughly)

Ive found a good 4:1 ratio works for me. Mix 1 lb of the powder with 4 gallons of distilled water

I'm not familar with the powdered stuff i have always bought by the gallon which goes a long way. Here is a link look at the top of the page for where to buy.

Bob

Ferric Chloride

Hello everyone this is Alex from Australia,

I know its late to reply here, but here is my advise on mixing ferric chloride 

Thumb Rule: Always mix powder in water , never pour water on chemical ,

Mix Ferric chloride in open area, 

Always wear mask and gloves  

RATIO

We are Mixing 55 pounds of bag in 35 ltr of water 

We are doing etching through Photoetching machine made by etchcut,India, capacity of tank is 240 ltr

so we mix around 6 bags with 210 ltr of water will make it almost 240 ltr 

By the way we do all type of Iron cuttings of sheets, generally we make 3d models from last 10 years using this wonderful machine here is the ref pic enclosed of 3d model