I have looked for these in the past when trying to fit something that required a deeper back box than what was in the wall. I couldn’t find anything so I ended up creating my own by modifying a standard surface mount box.
First, I carefully drilled straight through the threaded brass bushes and through the back of box with a 4mm drill to allow clearance for the 3.5mm screws. I then cut the back face out of the box using a Dremel (this can be done with a hacksaw by putting the blade through the knockout and then fitting to hacksaw frame). Any sharp edges should be removed with a file or a piece of abrasive paper.
Don’t forget to get some extra long 3.5mm screws. I bought the 75mm length as they are much easier to shorten than they are to make longer (Screwfix Cat No: 2792H)
By using this method to create your own spacer, you will have a wide choice of depths (>=16mm). You will also have a better chance of being able to find something that best matches the corner profile of your face plate. MK, LAP, BG, Crompton etc. all have slightly different corner profiles!
Answered by: Kryten1967
Date published: 2020-04-22
