Hi Phil,
i don't know what type of flux you are using down under.
I use a boric acid (hydrogen borate)[borax derived] / denatured alcohol mixture.
you add just enough denatured alcohol to dampen the mixture to make the paste.
i'm not sure what water does in combination with your flux
When my silver solder paste starts to get a bit dry I usually add a few drops of tap water to moisten it up again. Am I doing the wrong thing?
Cheers Phil