by magisticus » Sat Dec 16, 2017 3:18 am
It is worthwhile to understand first where such stone would likely come from which would be the bi-product of metal spiraling and therefore be held in abundance by people who engage in metal spiralling and not be worth much. Given how high you can get stone quality the clay quality in your tar kiln is less consequential.
Metal is up to q500s, finery forges q300s so there will be stones in the 400s. Unless using bone clay some of which is above 200 you are unlikely to get clay above q50 and that is not nearly enough gold to buy you that much bone clay. That said the clay counts for half the quality of the tar kiln and the tar kiln counts for quarter of the quality of the coal, so it takes 8 levels of clay to get 1 level of coal (q50 clay improves your coal by 6 levels, q200 clay by 25 levels which when your coal is around q300 is not a huge difference). Given that as you spiral, if that is what you intend to do, you get better quality stones and can build better quality tar kilns there isnt imo much point in investing bone clay in one stage of tar kiln.
To get better quality coal it would be more sensible to buy a better quality saw and/or the ability to make better quality trees to cut up with it. Ie assunimg you have q200 trees, a q100 saw would give you q131 coal in a q100 tar kiln and q181 coal in a q300 tar kiln whereas a q350 saw (which you could easily buy with those quills) would give you q223 coal in a q100 tar kiln and q273 coal in a q300 tar kiln.
As to the kiln, there are public kilns at community fair and aurora that will be better quality than anything you can build yourself.
I'm sure however that there will be plenty of peops prepared to extort your quills from you if that is really what you want!