Today I bought a 14" abrasive cut-off saw from (gulp) Harbor Freight.
I am loathe to buy orange power tools(except Fein). It better be yellow (Dewalt) or Red (Milwaukee).
But $50 (on sale; half price) for a brick biter can't be beat. I figure I'll burn it up on the oven. But it's less than renting or buying a wet saw.
It's a cheap tool. Literally and figuratively. $20 buys you a box of 5 cutting disks, enough to finish your dome.
Wear a dust mask, goggles, and earplugs. And do it outdoors. But it will bite a firebrick in half in about 15 seconds. The cut is smooth.
The sale ends May 30, 2006.