25mm holes through 1m wide walls?

[Lurch]

I cored all the holes for a boiler install in 0.6m stone walls and ended up needing a new core drill, SDS drill, 117mm core bit and 43mm core bit. Also none of the holes were exactly where I wanted them, and it took me 1/2 day just to drill the holes.

For a 25mm hole I would run a 32mm core, but take a couple of new bits and make sure your drill isn't about to give up anyway! Stick a length of pipe between the drill and core bit to sleeve it on the way in, if the middle is rubble then you shouldn't have to battle with trying to keep it clear once you're beyond half way through.

 

[kerching]

I saw that on the CEF tv behind the counter, I seem to remember it was flawed in some way??

Found it...did not think it was by Gripple though

http://www.gripple.co.uk/images/Markets/Building Services/Products/Thru-In-1® Sleeving System/Downloads/BUS-BROC-MEP-TI1-ENG.pdf

does not look like it is long enough for you, but.   Knowing your 'furtling abilities' I feel sure you could plagiarise it and cobble something similar to suit your needs

 

[Lurch]

That's kind of what I was meant with the sleeve behind the core, didn't realise someone had turned it into a product, that's another million I could have made.

 

[Marvo]

There are SDS drilling/sleeving systems available, not sure how good they are though...http://www.gripple.com/gb/en/p175/a152/thru-in-1-28-mm-sleeve