Step 3: Chop the top off
Originally I was going to remove the valve before I started this part but I had trouble getting a spanner around it as there is a safety valve on one side and the gauge on the other, I pulled the gauge off with pliers but it had a long brass section sticking out which got in the way. on the other 2 sides was the handle.
If you can get a spanner around your valve I would recommend heating the bottle where the valve connects, they seal these valves with a liquid weld which will return to liquid when heated up, this will make it a little easier to get off. I would also recommend using a length of steel pipe on your spanner to give you extra leverage.
ok back to the cutting, you need to allow enough on the top of the bottle for about 2 inches of refractory, I measured up 5 and a half inches from the top of the centre seem and marked them with a mark pen.
cut along the marked line using your angle grinder with a cutting disc, I managed to con my brother in to doing most of the work for me while I cooked him dinner ;-)
once the top has been cut off grind off the sharp edges with a grinding disc
here is by brother grinding the sharp edges off.