Enlarging a hole

[eddystone]

Like this; need to enlarge inside skin by maybe 4mm diameter outer skin more like 8mm diameter increase. Both layers about 3mm thick

 

[rudolph_hart]

The standard answer to enlarging a hole is to fill it (tap in a suitable sized piece of wood) and re-drill with a suitably-sized holesaw. With such a small increase you'll have to be careful to start accurately on centre, though.

Pete

+1.
Did this successfully when changing Depth transducer on my Dehler a few years ago.

 

[Dodgy Diver]

you can put 1 hole saw inside another one , then the 30mm will keep it as a guide and entered , then the bigger one will cut ?

 

[eddystone]

Dremel sanding cylinder worked perfectly

 

[Daverw]

Or small flap wheel in a drill

 

[jon and michie]

Easy - larger piece of wood placed over the existing hole - re mark the centre of the hole then use a hole saw