Sinking a patress

[FatGit]

Hi,

Looking for some advice. I have arround 20 currently surface fixed sockets and switches to sink in a 1930s semi. However, I don't want to re-decorate
Just wondering how you cut the boxes without destroying the wallpaper. I was thinking of scoring the outline of the box on the paper and then making the hole with an armag box sinker, which I can hire for £16 for the w/end. I do have an SDS drill etc.

Cheers!!

 

[electronicsuk]

Sorry, can't be done.

 

[FatGit]

Oh
I'm sure it was done when the lecky board did my parent's rewire but I'm probably mistaken.

 

[electronicsuk]

You can probably get close, but there's always going to be a gap around the hole you sink for the patress that you'll need to fill in, and the wall is never going to crumble in a predictable manner. This applies even if you use a sinking tool.

 

[securespark]

Sorry, can't be done.

Er. I beg to differ. I've done it. Several hundred times over the course of my career. You have to be VERY careful, but it can be done.

 

[RF Lighting]

The only time you can do it for sure is if you have dot and dab walls.

 

[crystal ball]

Sorry, can't be done.

Er. I beg to differ. I've done it. Several hundred times over the course of my career. You have to be VERY careful, but it can be done.

Yep, I used to work with a spark who could chop a box in so tight you could not get a fag paper in the gap, took a while but saved loads of time making good.

I think he used a sharp wood chisel to start, depends on plaster condition too

 

[FatGit]

Sorry, can't be done.

Er. I beg to differ. I've done it. Several hundred times over the course of my career. You have to be VERY careful, but it can be done.

How do you do it? Sinking set? SDS drill and chisel? Hand chisel?
Thanks again!

 

[securespark]

Nope. You can't use any power tools, except maybe a drill, but only very carefully. Sharp implements are very important.

PS to the OP - you may find some boxes attached to conduit behind the surface boxes. If you do, you'll have to have a rethink.

 

[FatGit]

Hello again
I've looked behind it and the wires are 'normal'. Just white T&E with the 'old' colours.

 

[Lectrician]

I always use a 5mm SDS drill to stich drill around the outline of the metal box on the wall - Then use an old wood chisel or my smallest cold chissel if thw wall is hard.....

Put tape on the drill bit to mark septh - wrap the tape the correct way to ensure it doesn't unwind!

If you are lucky you will get no split out at all.

If the plaster has blown - even slightly, it is going to make a little mess and filler will be required.

I fit is a dodgy old wall, more than filler may be required!

It is a skill that needs to be mastered. I can usually sink boxes in with ease to block walls - brick is another matter - it is all skill.

Dry lined dot/dab walls are easy as pie - Stud walls even easier It is the lathe and plaster you need skill on

 

[ColJack]

you can't use an SDS box sinker if the wires are already in.. you'd chop them off with the tool..

an old 3/4 wood chisel to do the job is great..

with the cables in situ, the hole will need to be slightly bigger to get the box in without damaging the cables, but socket and switch front are bigger that backboxes anyway so you have some room for manouvering and filler the gaps up after...

 

[FatGit]

I was going to put the new box a little below the current one, to avoid damage to the cables. They come in from the top.

 

[Steve]

forget it on thermalite. The wall will crumble away the moment you bring a drill near it!

 

[FatGit]

I don't think it is thermalite. Looks quite solid.