Which bit/method to enlarge 15mm hole to 26mm hole

[RichTeaBiscuit]

Hello,

I have a hole (where the peephole was) in my door that I want to enlarge to 26mm.

The outside is made out of some sort of plastic and the inside is foam of some sort. I don't want to shatter the plastic on the other side of the door.

I tried using a flat wood bit, but because the hole that exists is quite large, I didn't gain any traction and just tore off the paint around the hole. I assume I'll need a different type of bit, I have a 25mm masonary bit which I assume won't work. Which would be the best type to get for the job?

Any advice?

Photo attatched

 

[JohnD]

Hole saw.

Start from the outside. Finish from the inside. Plug the hole first so the pilot follows it.

Tell us what the hole is for.

 

[RichTeaBiscuit]

Thanks, what do you recommend using to plug the hole?

It's for a camera that works with my CCTV setup.

http://www.networkcameracritic.com/?p=2371

It's 26mm wide.

 

[RichTeaBiscuit]

 

[^woody^]

Endmill, or their more modern name a hinge cutter

 

[RichTeaBiscuit]

Thanks, if I fill the hole with polyfiller then drill, will that work better?

 

[JohnD]

a round piece of wood would be better. You can tap it in, doesn't matter if it is a tight fit because you will be cutting out that part. You need to be sure that your cutting tool will not skid or wander while you work.

 

[rsgaz]

26mm cone drill...

http://www.ebay.co.uk/itm/390015951562

Gaz

 

[RichTeaBiscuit]

The hinge cutter and piece of wood worked perfectly.

Now if I had only tried that first time round I wouldn't have taken off so much paint!

Cheers guys.