Making a 19mm hole bigger

[chriselevate]

Hi guys,

I've used a drill to make a 19mm hole in a piece for chipboard (the stuff that is covered). The hole is too small and need to be made to 25mm.

How would you go about doing this seeing as the centre of the hole is now cut out?

Thanks for any help you can give guys

 

[big-all]

use double sided tape attach 6mm or more mdf/ply/wood to the face and start again

 

[DC77]

Cone or step drill such as:-
http://www.screwfix.com/p/cone-drill-bit-set/45562?_requestid=3134840
or:-
http://www.machinemart.co.uk/shop/p...c-hss-stepped-cone-drill-set?da=1&TC=SRC-step drill

DC

 

[wotan]

Glue a piece of dowel into the hole plane flush, then find centre and using a hole cutter start again.

Wotan

 

[Dave54]

Drill a 25 mm hole in a piece of scrap, and clamp that to the work piece with the new hole centred over the existing hole. Bit dodgy if you're using a spade bit though I'd have thought.

 

[foxhole]

Drill a 25 mm hole in a piece of scrap, and clamp that to the work piece with the new hole centred over the existing hole. Bit dodgy if you're using a spade bit though I'd have thought.

Wrong way round, place timber over a scrap and use that to centre 25mm bit.

 

[foxhole]

Glue a piece of dowel into the hole plane flush, then find centre and using a hole cutter start again.

Wotan

Won't be able to plane without damaging surface.

 

[foxhole]

Cone or step drill such as:-
http://www.screwfix.com/p/cone-drill-bit-set/45562?_requestid=3134840
or:-
http://www.machinemart.co.uk/shop/p...c-hss-stepped-cone-drill-set?da=1&TC=SRC-step drill

DC

Can't guarantee keeping hole centered as it may wander without drill press.

 

[foxhole]

use double sided tape attach 6mm or more mdf/ply/wood to the face and start again

Would need to be attached to rear as face fixed would allow drill to wander as soon as it penetrates top ply etc.

 

[big-all]

use double sided tape attach 6mm or more mdf/ply/wood to the face and start again

Would need to be attached to rear as face fixed would allow drill to wander as soon as it penetrates top ply etc.

all depends
a hole saw no probs
a spade bit would be best with 12mm plus board thickness to reduce the chance off "chatter" enlarging or distorting the hole all depends on how accurate the hole needs to be

 

[Dave54]

Drill a 25 mm hole in a piece of scrap, and clamp that to the work piece with the new hole centred over the existing hole. Bit dodgy if you're using a spade bit though I'd have thought.

Wrong way round, place timber over a scrap and use that to centre 25mm bit.

Probably didn't make that very clear. The point is that you use the 25 mm hole as a guide for the 25 mm drill. So you put it over the 19mm hole. As long as the piece with the 25 mm hole is clamped it stops the drill wandering about. You could use it with any type of drill including hole saws, and hinge sinkers. I've done it lots of times. It works.

 

[foxhole]

Lets hope he gets his big hole.