tacky @ 400 degrees

So I am in the kitchen this morning SCRUBBING and SCRUBBING and SCRUBBING that roasting pan from yesterday's pork smoking. What I have noticed is that the ash deposits that are on the pan are really tacky and really stuck on. I just read Tim Roan's article "Matter" in the latest Log Book (Issue 41, 2010) about natural clays. The first sentence "Clay is ubiquitous" has me thinking that this is true with wood ash too. The compositional make-up of ash in this smoking was mostly birch, with a bit of maple mixed in and just like clay, its make-up will determine its glaze properties. This is not just determined by the "trees" but also the minerals that are found in the earth that the trees live in. In this case there is probably a high copper and iron content in the make-up of the ash as the water source (artesian well) for our house is just below those trees and our water has this make-up.
So where is this post leading? I am planning on some reconnaissance. I will be testing the fired quality of this ash at LOW temps (cone 04 or about 1900 degrees). I want to know if ash sprinkled into the glazes on my earthenware pots will cause any changes to that glaze. I am hoping to have a few students join me in the testing and recording of the results (maybe even ask one of the Chem teachers to join us in the fun).