My stone built Victorian barn has a huge truss across its centre. Because the roof is made from limestone flags, varying from 2" thick at the bottom to 3/4" thick at the top, there are two purlins a side hanging off the truss. The way the purlins were fixed to the truss is that a hole about 2"...
Try using "Celcon" blocks, lightweight aeriated concrete blocks, available from any builders merchants. They can be cut with an old saw or a line of holes drilled in them and then cut. They do degrade but are 1/10 the price of proper refractory bricks.
As a teaching your Granny to suck eggs...
Did you mean a fly cutter? I would buy (from a market stall) a pack of cheap diamond files and touch the "blades" up to give them a proper cutting edge and side relief so they do not rub and over heat. I don''t the term blade, its like a knife blade , something which is flat and tapered in all...
While the "Eccentric" tool has had many good reports, it is expensive and I feel that one should have at least two if not three sets of lathe tools, one for brass, one for mild steel and one for aluminimun , which would do for most plastics. The same comments go for replaceable tipped tools...