On 22/03/2014 17:41, Lobster wrote:
I've got an old cherry tree stump which I really want rid of. It's
probably about 10" high by 15" across, and the problem is that it's in an
awkward position at the foot of a banked area, and surrounded by paving
stones, so would be very disruptive and difficult to dig out. It's
inaccessible to a tree stump grinder (other than maybe something hand-
held).

Burning it out seems the way forward, and I've tried several times (over
years), burying the thing in burning coal. Trouble is the stump doesn't
really burn much as such; it just chars over, and has got quite dished on
top, but there's a lot more to go. Anyway, it occurred to me that maybe I
could try again this summer but first impregnate the remaining timber over
a period of time (maybe honeycombing it with a drill first) to encourage it
to burn properly. Anyone tried this? What would be good to use, that
wouldn't just evaporate off?

I'm not after getting the whole thing out - if I just get the stump below
ground level and cover it with a plant tub or something, that would be
fine!

Or any other constructive ideas!?

You can get angle grinder disks which are similar to a proper stump
grinder, basically a ring of chain-saw chain wrapped round a hub.
Sometimes used for "carving".

Drill a lot of parallel deep holes with a big (say 25 mm) auger to
remove a large proportion of the material?

I have used a 1 inch chisel in a 4 kg SDS drill to attack similar things
in the past.

As another poster said, saltpetre (potassium nitrate) is a good
oxidising agent if you can saturate the stump with it before applying
fire. Potassium permanganate is another possibility, perhaps easier to
obtain. When trying to purchase such things in kilogram quantities,
suggest blacking up, put on false beard, and speak with funny accent. (Not).