Repairing metal back box screw hole

psd99

psd99

psd99

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7 Sep 2008
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The left hand screw in thing fell off
Absolutely pita trying to get it back into place with pliers etc

bought some new lugs online but don’t fit properly

What are the best options to fix this? The right hand side screw is ok though
 
I'd just replace the box, they are about 40p. I wouldn't want a combustable material like wood inside the box. Should just be a case of isolating the power, disconnecting the cables, carefully cutting round the edge of the box with a stanley knife to separate it from the plaster, then pulling the box out. The hard bit is usually the cables entering the box can wedge the box in place so you have to rotate the box out. I usually make the plaster gap slightly bigger on the opposite side to the cable entry to make it a bit easier.
 
Get a self tapping screw and wind it in - Or find next size up screw to one already in there and a tap -drill it -tap it and done.

As said above -just get old box out and renew it -bit of a pain doing it but you won't have a problem further down the road.
 
Abyss said:
I wouldn't want a combustable material like wood inside the box.
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Easy enough to switch out the back box.

Wood was commonly used for mounting switches back in the day, so its not terminal to use wood :)
 
When u mean drill and tap
What do u actually mean? Like screw into the back box/wall?

The box is quite far into the wall any ideas which screw i would need?
 
Fwiw looking at the replies
Replacing the box might be the best long term solution but are they usually really stuck into the wall with all of that bonding thing around the socket?
 
psd99 said:
Fwiw looking at the replies
Replacing the box might be the best long term solution but are they usually really stuck into the wall with all of that bonding thing around the socket?
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Usually just unscrew it and with a bit of wiggling around it will come out, use a sharp knife to go around the edge of the box so you don't peel away any paint.... don't cut any cables though!
 
psd99 said:
When u mean drill and tap
What do u actually mean? Like screw into the back box/wall?

The box is quite far into the wall any ideas which screw i would need?
Click to expand...
I mean drill a hole in the back of the actual metal backbox and then tap the hole with the correct thread, then use an extra long screw that will reach the back of the box.
The easiest solution is to use the thing from the link I posted above.

The "best" solution is to replace the box but it depends how well it is fitted into the wall and how willing you are to patch up whatever damage you cause removing/replacing it
 
I took the lug from another backbox and used JB Weld. It held strong enough to get the screw in so the faceplate looks fine.
Bit of a bodge but so what. Just don't over tighten the screw.
I think I might have used some tape or a prop to hold the lug in place while the JB Weld set.
 
I've never seen a backbox that would come out easily. Another vote for JBweld on a spare lug.
 
Drill 3mm hold in back of box in line with where it needs to go, and run re-threader through, use longer plate screw, bare in mind, that if this is the adjustable lug, then you'll loose most the the adjustment, so you've got to get it pretty much right where it needs to be
 
https://www.toolstation.com/extension-stud/p79641

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Join however many of these extenders together. Drill a small enough hole in the rear face of the box for this to tap into should hold firm enough.
 
Easiest way is to glue a lug from another box behind the threadded one so the threadded screw can tap into that and it can't pull through when tightening it. You don't even need to glue it really, just hold in position behind the existing with insulating tape wrapped around both, cut a small hole for the screw to pass through, job done.

Or just glue/tape a nut behind if you have the right size but it's a bit more fiddly.
 
all of the answers with the exception of "replace it" are going to cost you far more in time, money and effort than simply replacing it. It takes about 10mins to change a knockout and that's being generous.
 
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