Question about Shades

[Ammonius]

Recently, I have noticed a trend:

If I thin some Agrax Earthshade with water (about 2:1 water to Shade), I get grey-white residue in the recesses of my models instead of the expected thinned brown layer. Here are some bullet points:

 

This seems to happen with Tap water and distilled.

This happens on grey paint that has had at least overnight to dry.

This happens even when I try to minimize "puddling"

 

Not long ago, it seemed that I could make a batch of thinned shade, and really slop it on, and all was well. Lately, it is a real problem. Has anyone encountered this? Is there a shelf life on the new shade formulas?

 

Any help will be appreciated, I feel like I'm missing something obvious.