stuart noble wrote:
On 13/05/2013 21:12, John Rumm wrote:
On 13/05/2013 20:54, Tim Watts wrote:
On Monday 13 May 2013 19:25 imanc wrote in uk.d-i-y:


I'm trying to fit 4 25mm back boxes into walls. I've pepper potted
the area with the drill

To a fixed depth? I wrapped tape around my drill as a depth marker
when doing this.

then used a cold chisel to clear out the plaster and
brick. However, the result is not smooth. There's a lumpy mess and
some cracked brick that is stil somewhat firm, and the back box
doesn't seat right. With one recess the back box is about 5mm too
deep. I'm wondering if I can build up the chase with some polyfilla or
something to make it straight and the right depth before fitting
the back box?

I know that an SDS drill with correct chiselling attachment would
do a much neater job, but I don't have one to hand.

I've got 3 more holes to chisel out so any advice would be
appreciated!

I had the same problem on the odd occasion - when too enthusiastic
with the
SDS or the bricks were a bit crap. Mix a bit of 4:1 mortar and lob
it in the
back of the hole. Bed the box in to this. If you add a bit around
the side
you can not bother with the fixing screw(s).

I keep an old bag of bonding plaster for such occasions... slap it
in, it goes off quick.


Industry standard IME. I guess that's why our electrical wholesaler
has it stacked by the front door.

Bloody good stuff that out of date bonding.

--
Adam