fixing electric socket to tiled wall

[pooksahib]

Hi. For years, my parents have had this socket in their utility room. The screws are round-headed and don't allow the plugs to be fully inserted. Apart from having to jiggle the plug occasionally, it didn't bother them.

It bothered me, though, so I intended to replace the screws. I took one out but now find that it won't go back – it seems like there's just fresh air behind the plate, nothing to bite into. Can anyone suggest what has happened here (i.e. why were inappropriate screws used) and how best to fix it?

Many thanks for any advice offered.

 

[Burnerman]

Maybe the screws were too long in the first place but if you remove them both and gently pull the socket away, you'll see the lugs that the screws fit into. They do tend to float a little to allow the socket to be made level when fitting.
John

 

[Tigercubrider]

I assume that you turned off the power at the mains?

If you visit a DIY shop or look online you can see a metal back box to understand what should be in there
Presumably there is one.

You can buy replacement screws in the same aisle and it is possible that somebody has bodged it with screws that are too long. The problem may be that the screw bottoms out on the box before being tight.

 

[foxhole]

You have missed the threaded lugs they screw into, can be a fiddle with long screws.

 

[pooksahib]

I'll be damned... It took a bit of jiggling but it does screw back in after all. I'll see about getting proper screws now. My thanks to you all.

 

[Tigercubrider]

Sometimes people use what they have to hand (bad)

You may find it easier to change the screws one at a time, so that the front plate stays in position.
they are cheap so if you don't know the length start with 25mm

 

[pooksahib]

Well, this is depressing... I bought some 'switch box' screws (50mm, flat head). I can screw in the existing 'round head' virtually all the way by hand. The new flat head sticks almost immediately and can't be turned even with a screwdriver. The screws look identical bar the head.

Can anyone suggest why the new screw won't 'take' and what I might try to fix this problem? (e.g. run a file around the tip...)

Many thanks.

 

[Tigercubrider]

It's possible that the wrong screws were used and have re -tapped the holes in the box.
Rather than try to "fix" the box you could try cutting the original screws that were in there.

To do this, first examine the end of the screw to ensure that it isn't messed up.
I would visit B&Q or better still a decent ironmonger where you can try various nuts on the thread.

When you have the correct nut for that bolt, you know it's size incase you mess up.
ensure that the nuts run all the way up the bolt to check that the entire thread is what you need.

You need to find a vice and hacksaw. A dremel and cutting wheel is ok if you practice on some spare stuff.)
Thread a couple of nuts onto the bolt and use them to hold the bolt in the vice.
Some molegrips on a work surface might do but a vice is better

The nuts need to be right at the edge of the vice and you will cut the thread right where the nut is, using it as a guide, and cut the end leaving the nut on the bolt.
Then spin the nut off and it should clean up the thread so that it fits into the mains socket but is now shorter.

This will work if the original bolt is the right thread but too long
not if it's the wrong thread that's been forced.

a last resort is to use your new bolts and force them into the metal back box but if you mess up, the box has to come out.
In theory the bolt deforms the thread of the box to form a new thread. Or total failure.

 

[phatboy]

It's possible that the wrong screws were used and have re -tapped the holes in the box.
Rather than try to "fix" the box you could try cutting the original screws that were in there.

To do this, first examine the end of the screw to ensure that it isn't messed up.
I would visit B&Q or better still a decent ironmonger where you can try various nuts on the thread.

When you have the correct nut for that bolt, you know it's size incase you mess up.
ensure that the nuts run all the way up the bolt to check that the entire thread is what you need.

You need to find a vice and hacksaw. A dremel and cutting wheel is ok if you practice on some spare stuff.)
Thread a couple of nuts onto the bolt and use them to hold the bolt in the vice.
Some molegrips on a work surface might do but a vice is better

The nuts need to be right at the edge of the vice and you will cut the thread right where the nut is, using it as a guide, and cut the end leaving the nut on the bolt.
Then spin the nut off and it should clean up the thread so that it fits into the mains socket but is now shorter.

This will work if the original bolt is the right thread but too long
not if it's the wrong thread that's been forced.

a last resort is to use your new bolts and force them into the metal back box but if you mess up, the box has to come out.
In theory the bolt deforms the thread of the box to form a new thread. Or total failure.

I find this to be generally poor advice except for leaving a but on the bolt when working.

I usually cut screws down in the cutter part of pliers, it's neat enough for the job and takes 2 seconds. I don't bother with a nut on it though.

NEVER force the screws in, if they don't go there is a reason. My guess would be imperial threaded box. In which case you can get an m3.5 thread cutter for a couple of quid and gently re-thread the old box. Easy peasy.

 

[JohnD]

I was taught to always put a nut or two on a bolt or stud before cutting it. It can save a lot of time trying to wangle a nut onto the damaged thread afterwards.

yes, and this is the lug rethreader

 

[pooksahib]

Thanks for the tips. I don't think the length of the existing screw is the issue, I reckon it's simply that it's round head is just a tad too big. I bought a pack of 'switch box' screws (flat head) which comprised 4 screws and 4 nuts. The new nut slips easily up and down the length of the OLD screw but new nut/new screw only just goes on then stops.

That suggests to me that the thread at the tip of the new screw is 'different' and so won't work in the existing setup. Does that make sense?

 

[DaveHerns]

Switch screws with nuts ? Think you have the wrong product

 

[pooksahib]

The packet says Switch Box, the screws resemble the existing ones so I'm satisfied I have the correct product. True, I couldn't see any reason for the nuts...

 

[DaveHerns]

Switch off the mains , pull the socket forwards and take some photos of what's behind. Can you measure the depth to the back of the metal box?

 

[Burnerman]

The official thread is 3.5mm - maybe you just got one cross threaded? Try the nut on the original screw to see if they are compatible.
John