Core drilling brick wall - very slow.

[GB]

Stuck it under a waterfall and waited 1000 years?

[whisky-dave]

in the hebrides rather than an axe which would have broken the ring.

Nah I saw a program which showed how it was done on the isle of sky, didnlt take long for a small hole. T;ws the northerner with balck hair can't remm ebr his name but he has a funny accent ;-) It was a 3 part progam about how people lived there 3000+ years ago.

[Martin Brown]

The ones that are particularly difficult to core drill are old early bricks that still have some small roundish flints and fine pebbles in. The guy who installed my wood burning stove took around 2 hours and wrecked one core drill to go through a 3 brick solid wall of this stuff.

Essentially some of the pebbles work loose in the brick and spin around until they shatter or jam the drill thumping the guy using it. It is a bit like the hardened anti saw rollers put into some door locks.

Sometimes the pebbles can put up a lot more resistance to cutting than the clay brick if they are high in quartz or other hard minerals.