Jack
Limewash recepies are pretty simple after you have been able to sort out which lime you you want or are able to purchase, and which ground is actually appropriate for limewashing.
Suppose you have the answers to these two problems then you will find yourself with either a powdered lime or a lime putty.
If the lime is dry it is a good idea to convert it to lime putty first and let it sit for a couple of days or more. At this stage the putty will last a very long time provided that it is stored in a closed container.
Then all you have to do is to mix the putty with water until it looks like milk. You can add pigments to the mixture if you want colors in your limewash. Choose a lime proof pigment. All earth pigments are lime proof and make beautiful colors. I can tell you more about that if you need.mix the pigment thoroughly with water to make a paste before you incorporate it in the limewash.The amount of pigments can only be a fraction of the volume of lime putty, or it will not be binded.
To paint the walls you will need a big heavy brush such as the ones that are used to glue wallpaper. You may be able to find one that is specially designed for this purpose. Do not forget that lime is caustic to brushes. Rinse your brushes very well after use and wash them with soap.
For more binding power in your limewash you add casein or make your limewash with skim milk.
If you want your lime wash to be more waterproof and sturdier you can add a fraction of linenseeds oil.
Lime wash is very flexible and could be used as a base for all kind of paint recepies. In France they are paints on the market which are a combination of lime and acrylic. I would not go that route because it defeats the whole purpose of using lime which is (on top of beauty, bacteriacidal properties and the lack of negative environmental impact) to allow breathability. Also a plain limewash has a powdery look that is sort of taken away if we add synthetic resins.
A lime/ linen oil combination is also less powdery but it feels right and it is a good choice for a bathroom.
A lime / casein combination stays powdery and had enhanced adhering power.
Do not forget that no limewash will "stick" to a wall that is not porous (looks darker when you wet it) and you should always wet your surface before you limewash it!
I hope it helps. You will find more info browsing through this site or the limeonline site.
Myriam