Well, I think I finally licked the issue with white spots showing through the porous pumice. I made a goop of water, PVA, burnt umber craft paint, and a bit of playground sand (just for laughs).
And here it is with a barely noticeable dry-brush of "spice brown." More dry-brushing to come, but it's beer-o-clock here...
Here's a shot of various dry-brush techniques for the logs. Brown base, Brown-Black base, and Black base. I'm trying to decide what look to go for. Newly cut logs, ancient logs, or something in between.
I may defer this decision until more of the dry-brushing is done on the base to make sure the fence stands out color-wise.
Not as much progress as I'd hoped, but I was sick again dammit. Twice in two months. I may have to start eating apples again...