hole driller

[Norman]

I want to fit a cooker hood. It requires a 5"venting kit ( which I still have to get) It is to go through a kitchen wall, that is built with dense blocks rather than brick. I need to put a 5" hole though the wall, and went to hire a diamond drill cutter. They only hire them for the day, and once all the bits I need are added on it's around £50.

Would it not be possible to use a long smaller drill , and work my way round the 5" circle, and then knock the centre out (hopefully) or is it better to pay the £50.00

Thanks

[EricP]

(Bottom item.)

[Palindrome]

You can buy inexpensive core drills to use with an electric drill. But, unless the electric drill is intended for driving such size core drills, you are likely to wreck it in the process. Also watch the arbour size. Many core drills have too big a diameter for a lot of electric drills. You can turn them down on a lathe - if you have a lathe.

Drilling a series of small holes can work very well. But I wouldn't do it without an SDS-type electro-pneumatic drill. And it will take a lot of time and many, many rude words.. It isn't as easy as it sounds. A normal hammer drill? Forget it.

So, I would suggest hiring the professional tool for the job*. It will do it quickly and easily and produce an excellent result.

*If you already have an electric drill rated for driving that size core drill, then you probably wouldn't be asking the question.

[ARWadsworth]

It depends on how neat you want the hole and how much making good you are prepared to do if some of the dense block breaks away. It is a technique I have used many times successfully. Usually a pilot hole through the centre of the hole from inside to out and then work around the circle from both inside and out if you have a cavity wall.

Adam

[John Fox]

I've used both approaches in the past.

Hiring a drill is much easier and give a neater hole. Watch the torque on them though, they have a heck of a kick.

An ordinary hammer drill takes a lot longer and as someone else pointed out, consumes a lot more rude words.

John Fox

ARWadsworth wrote: