Easy way to make downlighter hole bigger?

[davidr]

i'm upgrading downlights in plasterboard and need to make existing 60mm holes 75mm for new downlights with same centres. i've got right size hole saw for drill but how do I make them bigger ?

thanks

 

[Spark123]

I'd do it by getting a piece of wood, drilling a 75mm hole in it and use it as a guide for the hole saw over the hole to get it started. Take care that the wood doesn't spin and get your fingers.

 

[GarethW]

Drill a 75mm hole in an old piece of plywood/mbf/chipboard,ect make sure that the board is big enough for you to place your hand next to the hole.
Hold the board with lots of pressure on the ceiling and drill your enlarged hole.

 

[PrenticeBoyofDerry]

how many holes and do you have access from above?

 

[davidr]

how many holes and do you have access from above?

Four holes and yes, I can get into loft area directly above ceiling

Thanks all
David

 

[PrenticeBoyofDerry]

I normally template hole and cut with dry-wall saw but......
You could make a template, like this:
If you can cut a 60mm piece of ply or plasterbord (ideally the thickness or approx of your ceiling) with 60mm hole cutter, so you have 60mm disc, that fits snugly in to exiting holes.
Then cut a bigger piece of timber/platerboard, this can be any shape, so it overlaps the 60mm disc and the intend 70mm hole. Align the two together and fix/screw up together. Pilot a central hole through both these pieces, so it takes the holesaw guide/pilot
Then take trip in to loft, place the template in to the holes 60mm hole, 60mm side down, so snug in existing hole and resting by means of larger piece, put a weight on top to restrict movement of template, but don't cover guide hole, then you can drill from underneath.

 

[Scoby_Beasley]

I was gonna say... but PBoD beat me to it!

It may seem like the long winded way (up n down loft) but infinitely better than trapped fingers/plank of wood spinning above yer head!!

 

[RF Lighting]

You can get a holesaw arbour with a longer thread. This allows you to put the 75mm holesaw on and then fit the 60mm holesaw inside it.

The 60mm holesaw then becomes a 60mm pilot bit and allows you to drill your 75mm hole.

 

[Scoby_Beasley]

You can get a holesaw arbour with a longer thread. This allows you to put the 75mm holesaw on and then fit the 60mm holesaw inside it.

The 60mm holesaw then becomes a 60mm pilot bit and allows you to drill your 75mm hole.

Well, there you go!! Any link RF?

 

[RF Lighting]

http://www.reloadtools.com/main.htm?pro.htm


I've had one for years. I got it from the wholesalers, but haven't seen them on sale for ages. You might have to do a bit of scouring on the internet!

 

[davidr]

I normally template hole and cut with dry-wall saw but......
You could make a template, like this:
If you can cut a 60mm piece of ply or plasterbord (ideally the thickness or approx of your ceiling) with 60mm hole cutter, so you have 60mm disc, that fits snugly in to exiting holes.
Then cut a bigger piece of timber/platerboard, this can be any shape, so it overlaps the 60mm disc and the intend 70mm hole. Align the two together and fix/screw up together. Pilot a central hole through both these pieces, so it takes the holesaw guide/pilot
Then take trip in to loft, place the template in to the holes 60mm hole, 60mm side down, so snug in existing hole and resting by means of larger piece, put a weight on top to restrict movement of template, but don't cover guide hole, then you can drill from underneath.

Brilliant ! thanks very much to all, this is the way I'll go

 

[17thman]

can we have a thread on making the cut outs smaller? without using those horrible flanges or overboarding?

 

[RF Lighting]

There's already a step by step guide in the wiki...

 

[studentspark]

Cut some strips of plaster board, that will fit through the existing hole, not to long.

Put some grip fill on each end

Place strip through hole and gently pull down on strip for grip fill to make contact with ceiling, let it go off

The strip will support the drill bit.

Drill new hole.


You can drill a pilot hole through strip, but you will need to centre this is the 60mm hole

 

[sparkybird]

surely if it's plasterboard it's much much easier and quicker to use one of these??

http://www.tlc-direct.co.uk/Products/DR68482.html