diamond

Hi Anyone ever tried engraving ceramic tiles? I have just engraved a pattern on a glazed ceramic tile on a CNC machine with a diamind drag bit, should the surface be sealed and if so, what should be used. The one I have done will be used as a trivet, but I would like to create some more for...

Just bought this off eBay for £35 inc P&P (Included hex arbour kit not shown) as I need to drill a 6"/150mm hole through a wall for a short piece of 6"/150mm (External diameter 156mm) solid ducting what is to be used as a exhaust outlet for a portable AC Unit. 152mm Core Drill by eveares posted...