Wood'nCoal wrote: although if I really fire it too hot I'll end up with a clinker too large to pass through the grates.
Not sure where the coal came from but it was red ash and the new customer had a clinker the size of soft ball.
That was one nice thing about the white ash, rarely had troubles or complaints from anyone. From a dealers perspective even if the Superior is has a higher BTU than the best white ash I wouldn't want to be delivering it. Other than the a few loads where the customer had a legitimate complaint which was really rare the biggest problem I had was the one fall they were putting out some really low ash coal around 6% and people were having trouble keeping it lit.
Most were quite happy with it but some needed a little guidance to get it burning right.
My Uncle put some coal in my Grandmothers once the stuff was so hard it wouldn't burn.
It's pretty easy to spot the red ash, it has duller grayer look (not to be confused with bone). The white ash is pitch black and really shiny, the hardest will have the consistency of glass.