Hi guys, I seem to have a problem with Tamiya X-11 Chrome/silver. Every time I spray with it I get a really bad result which look very blotchy and dithered.

I've tried all sorts of thinning and mixing with other colours but it always looks like this. I get the same result with Humbrol 11, it's like the silver pigments just don't want to blend into a single colour.

Is this just the nature of these paints and I should use something else (going to try model master metalizer) or am I doing something wrong?
See pic:.. click for bigger view