Hi Chailatte,
I like your post, but I wasn't suggesting buying 500 litres of kerosene just for the sharpedge. We have oil as our central heating fuel and the 500 figure comes from the fact that most companies have that as a minimum delivery quantity. At that quantity the typical price per litre is around 60p. I suppose it can be bought by the gallon in a hardware shop but as has been said, those sort of outlets are rare these days and the cost would probably be significantly more. We used to have a hardware store in our local town, just as people remember - big wooden counter with the very helpful and knowledgeable shopkeeper standing behind dressed in long brown warehouse coat. We knew they sold kerosene (or paraffin as we always called it) because the shop stank of it.
There even used to be a van which drove down out street on a weekly basis, which had a paraffin tank inside. The driver would open the back doors of the van and there it was - a big tank with a brass tap at the bottom. We would fill our own containers. That van stank too.
Our local garage has the usual petrol and diesel pumps, but at the back of their yard they have a pump for red diesel and one for kerosene, so it might be that there are lots of these are around but people wouldn't know about them. We buy red diesel there but as I said, we get the kerosene delivered.
I am still undecided about which oil to get for the sharpedge though. The tempting thing about tractor hydraulic oil is the fact that I have a 25 litre drum of it in the shed, but I don't want to clog up the sharpedge stone if it is not a suitable cutting lubricant, hence my original post. Decisions, decisions ...
K