In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust.

Today I tried a new method (for me)
I purchased a couple of these for my multi-tool

https://www.saxtonblades.co.uk/fein-...-end-cut-blade

https://tinyurl.com/yypkfmba

and on the slowest speed cut the outline for two double 35mm back boxes
and the channel for the wiring. This was into soft brick overlaid with
10mm of old fashioned (horse hair) plaster. A few bricks were more like
cinder and were harder. While it did create some dust and a mask is
advisable most of the dust just dropped to the ground rather than
becoming mainly airborne. If doing the same again I may consider a spray
of water to further contain any dust.

I also used the multi-tool to cut diagonal slots in the "waste" area of
the back boxes. The material to be removed came out fairly easily with
the use of a scutch chisel and lump hammer leaving very clean edges and
corners.

https://www.toolstation.com/draper-scutch-chisel/p18718

Cutting the back box outline to a depth of 35mm+ probably took 10x
longer than with a angle grinder but possibly saved 10x the time
cleaning up the dust afterwards.

The blade does show signs of damage but probably could manage the same
again before discarding.

On tip is to often move the blade out of the work to clear the debris.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust.

Today I tried a new method (for me)
I purchased a couple of these for my multi-tool

https://www.saxtonblades.co.uk/fein-...-end-cut-blade


https://tinyurl.com/yypkfmba

and on the slowest speed cut the outline for two double 35mm back boxes
and the channel for the wiring. This was into soft brick overlaid with
10mm of old fashioned (horse hair) plaster. A few bricks were more like
cinder and were harder. While it did create some dust and a mask is
advisable most of the dust just dropped to the ground rather than
becoming mainly airborne. If doing the same again I may consider a spray
of water to further contain any dust.

I also used the multi-tool to cut diagonal slots in the "waste" area of
the back boxes. The material to be removed came out fairly easily with
the use of a scutch chisel and lump hammer leaving very clean edges and
corners.

https://www.toolstation.com/draper-scutch-chisel/p18718

Cutting the back box outline to a depth of 35mm+ probably took 10x
longer than with a angle grinder but possibly saved 10x the time
cleaning up the dust afterwards.

Indeed, angle grinders and masonry inside are not to be recommended. If
you must do it, then a wall chaser fitted with just one disk will do a
very much better job of containing the dust.

I usually use similar carbide/diamond blades for sinking holes through
tiles, but for "normal" walls (or once thought the tiles), I normally
use a small SDS chisel to sink the perimeter to depth (marking that on
the shaft with a ring of tape), then a wide SDS chisel to knock out the
infill an plane down the back. Its a reasonable trade off of speed and
mess.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust.

Today I tried a new method (for me)
I purchased a couple of these for my multi-tool

https://www.saxtonblades.co.uk/fein-...-end-cut-blade


https://tinyurl.com/yypkfmba

Not compatible with DeWalt:-(



--
Adam

On 09/10/2020 17:17, alan_m wrote:

Cutting the back box outline to a depth of 35mm+ probably took 10x
longer than with a angle grinder but possibly saved 10x the time
cleaning up the dust afterwards.

I've some to do, how long roughly?

(I get that my mileage may vary)

On 09/10/2020 19:45, R D S wrote:
On 09/10/2020 17:17, alan_m wrote:

Cutting the back box outline to a depth of 35mm+ probably took 10x
longer than with a angle grinder but possibly saved 10x the time
cleaning up the dust afterwards.

I've some to do, how long roughly?

(I get that my mileage may vary)

Probably 30 minutes to cut 3 metres of outline to average depth of
around 30mm (35mm+ for the back boxes). Possibly about the same to
knock out the waste with the chisel. I wasn't particularly in a hurry
and was attempting to achieve a neat result, which I did. I found some
way into the job that repeatedly removing the blade from the slot (with
the multi-tool still running) removed debris and was actually faster
than trying to cut a longer part of the outline slot without
withdrawing the blade. I was running the multi-tool at its slowest speed.

What I found helpful was to first make a shallow outline slot of maybe
5mm depth all around the area to be cut out before plunging in the tool
to get a deeper slot

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

I don't think this is a new idea though, but the equipment may be. When
back in the 70s we had this house rewired they cut the edges round using
some kind of hammer tool and then just gunged out the middle. That was a
technical term used by the elecctrician.. grin.
Brian

--
--
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"alan_m" wrote in message
...

In the past I've used the angle grinder to chase out electrical back boxes
and have created an amazing amount of dust.

Today I tried a new method (for me)
I purchased a couple of these for my multi-tool

https://www.saxtonblades.co.uk/fein-...-end-cut-blade

https://tinyurl.com/yypkfmba

and on the slowest speed cut the outline for two double 35mm back boxes
and the channel for the wiring. This was into soft brick overlaid with
10mm of old fashioned (horse hair) plaster. A few bricks were more like
cinder and were harder. While it did create some dust and a mask is
advisable most of the dust just dropped to the ground rather than becoming
mainly airborne. If doing the same again I may consider a spray of water
to further contain any dust.

I also used the multi-tool to cut diagonal slots in the "waste" area of
the back boxes. The material to be removed came out fairly easily with the
use of a scutch chisel and lump hammer leaving very clean edges and
corners.

https://www.toolstation.com/draper-scutch-chisel/p18718

Cutting the back box outline to a depth of 35mm+ probably took 10x longer
than with a angle grinder but possibly saved 10x the time cleaning up the
dust afterwards.

The blade does show signs of damage but probably could manage the same
again before discarding.

On tip is to often move the blade out of the work to clear the debris.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be. When
back in the 70s we had this house rewired they cut the edges round using
some kind of hammer tool and then just gunged out the middle. That was a
technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.


--
Colin Bignell

On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
Bob Eager wrote:
On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!

+1

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 10/10/2020 09:27, Bob Eager wrote:
On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!




I'm always worried on this 100 year old house bashing the hell out of
walls (brick lime mortar or lathe and plaster) for fear of creating more
cracks, especially of the other side of the wall which has just been
decorated.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

In article ,
alan_m wrote:
On 10/10/2020 09:27, Bob Eager wrote:
On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!




I'm always worried on this 100 year old house bashing the hell out of
walls (brick lime mortar or lathe and plaster) for fear of creating more
cracks, especially of the other side of the wall which has just been
decorated.

My BiL, when chasing out the party wall to take a cooker point hit rather
too hard and the next door neighbours . looking through the hole said "Will
you take your brick out of our bath."

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.

--
*If they arrest the Energizer Bunny, would they charge it with battery? *

Dave Plowman London SW
To e-mail, change noise into sound.

On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


Not much use IMHO.

--
Adam

On 10/10/2020 11:24, charles wrote:

My BiL, when chasing out the party wall to take a cooker point hit rather
too hard and the next door neighbours . looking through the hole said "Will
you take your brick out of our bath."


A friend did similar with a cooker socket back box but on an internal
wall. There wasn't a hole but a bulge in the other side of the wall
where the plaster was held on only by the wall paper.

I found by cutting the outline grooves with a multi-tool first that I
didn't need to hit the wall square on to remove the waste. With a long
handled Srutch chisel I was hitting the brick sideways at an angle 30
degrees to the horizontal.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 10/10/2020 13:44, ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


Not much use IMHO.



They seem only to be demonstrated going into light soft aerated concrete
(breeze) blocks



--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

In article ,
ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall
box.

Seen these and do wonder how well they work.


Not much use IMHO.

What I suspected. ;-)

--
*If only you'd use your powers for good instead of evil.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
alan_m wrote:
On 10/10/2020 13:44, ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


Not much use IMHO.



They seem only to be demonstrated going into light soft aerated concrete
(breeze) blocks

You don't need anything clever with those.



--

--
*Husbands should come with instructions

Dave Plowman London SW
To e-mail, change noise into sound.

On 10/10/2020 16:34, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall
box.

Seen these and do wonder how well they work.


Not much use IMHO.

What I suspected. ;-)


It really does depend on the brick.

If it is red brick you get red brick dust and are left with nothing to
fasten the back box to, if is black brick you are left with black brick
dust and nothing to fasten the the back box to.

Other coloured bricks are available.


--
Adam

On 09/10/2020 19:22, ARW wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust.

Today I tried a new method (for me)
I purchased a couple of these for my multi-tool

https://www.saxtonblades.co.uk/fein-...-end-cut-blade


https://tinyurl.com/yypkfmba

Not compatible with DeWalt:-(



"Perfect for chasing into plaster and some bricks for electric
sockets/cables "

And only suitable for 'some' bricks, which means the soft ones
that could be drilled, chopped out easily anyway.

On 10/10/2020 09:27, Bob Eager wrote:
On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but the equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!



Mark box outline+5mm on wall, put tape on SDS bit for depth required (or
set depth bar on SDS drill), drill many holes to desired depth, use a
scutch chisel and lump hammer to knock-out between holes, and a wide SDS
chisel to "plane" the bottom of the hole flat.

On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.

I bought one many years ago, before I knew what I was doing. OK on light
block but useless on brick or dense block, lots of dust too.
I must put mine on feebay so someone else can find out how useless they
are ;-)

On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


I've only watched them being used. The chap doing the work was recessing
into HD concrete blocks. It was a two-part job. First, he used a
circular cutter, which looked a bit like the front end of a tunnel
boring machine with a pilot drill in the centre, to cut a hole to the
right depth. The pilot hole provided position for the sinker tool, which
quickly converted the round hole to a square one. It seemed both quick
and effective.

--
Colin Bignell

On 10/10/2020 11:24, charles wrote:

My BiL, when chasing out the party wall to take a cooker point hit rather
too hard and the next door neighbours . looking through the hole said "Will
you take your brick out of our bath."

Similar thing happened in reverse for my son in law back in his bachelor
days when the pub next door was having some alterations done. They kept
him happy until the damage was fixed by passing pints to him through the
hole.

On 10/10/2020 13:44, ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


Not much use IMHO.

ok on soft "cement foam blocks" or similar, not much cop any anything
hard. IMLE.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 10/10/2020 16:37, Dave Plowman (News) wrote:
In article ,
alan_m wrote:
On 10/10/2020 13:44, ARW wrote:
On 10/10/2020 12:40, Dave Plowman (News) wrote:
In article ,
nightjar wrote:
On 09/10/2020 17:17, alan_m wrote:

In the past I've used the angle grinder to chase out electrical back
boxes and have created an amazing amount of dust....

You can buy box sinking tools for use with hammer drills that cut the
hole exactly to the right shape for a single or a double gang wall box.

Seen these and do wonder how well they work.


Not much use IMHO.



They seem only to be demonstrated going into light soft aerated concrete
(breeze) blocks

You don't need anything clever with those.

True, but the main attraction is the right sized hole cut cleanly and
fast. So they have a place if you need lots of cut-outs in the right
kind of wall.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 10/10/2020 18:10, wrote:
On 10/10/2020 09:27, Bob Eager wrote:
On Sat, 10 Oct 2020 06:27:28 +0000, jon wrote:

On Fri, 09 Oct 2020 20:52:26 +0100, Brian Gaff \(Sofa\) wrote:

I don't think this is a new idea though, but theÂ* equipment may be.
When back in the 70s we had this house rewired they cut the edges round
using some kind of hammer tool and then just gunged out the middle.
That was a technical term used by the elecctrician.. grin.
Â* Brian


I've done it quite successfully by hand with a cold chisel and hammer.

Easier with an electrician's bolster!



Mark box outline+5mm on wall, put tape on SDS bit for depth required (or
set depth bar on SDS drill), drill many holes to desired depth, use a
scutch chisel and lump hammer to knock-out between holes, and a wide SDS
chisel to "plane" the bottom of the hole flat.

I've also used a sds drill with a 20mm hole cutter. Mark the centres of
8 holes (for a 2 gang box) and then drill the 8off 20mm holes to the
required depth. The hole cutter plus the pilot drill hole removes much
of the waste just leaving narrow pillars of brick that can easily
removed with leverage or hitting with a chisel. Only the corners and
edges then need to be cleaned up afterwards. I found with this
technique that drilling all the pilot holes first was advisable.

As I indicated before I'm very wary about hammering the internal walls
in my house too hard as I'm sure that some of the 100 year old plaster
is only held on by its own will power On walls where I have removed
plaster in the past it came off very easily.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

In message , at 14:21:30 on Sat, 10
Oct 2020, alan_m remarked:

My BiL, when chasing out the party wall to take a cooker point hit rather
too hard and the next door neighbours . looking through the hole said "Will
you take your brick out of our bath."


A friend did similar with a cooker socket back box but on an internal
wall. There wasn't a hole but a bulge in the other side of the wall
where the plaster was held on only by the wall paper.

We've just had our bathoom refurbished (I didn't do the work myself) and
it turns out the old bath rim was set into a slot in the wall between
the bathroom and a bedroom. With only wallpaper on the bedroom side.
--
Roland Perry

After serious thinking nightjar wrote :
You can buy box sinking tools for use with hammer drills that cut the hole
exactly to the right shape for a single or a double gang wall box.

They only work where the wall is breeze block or similar.