Drilling a hole in bucket lid for an airlock grommet

[AndrewJB]

I decided to purchase a new fermenting bucket last weekend but the lid didn't come with a hole pre-drilled for an airlock grommet. (This one - https://www.the-home-brew-shop.co.uk/30-litre-fermenting-bin-with-litre-scale.html)

What's the best way of drilling the hole? The yellow grommet I picked up from the shop is designed to fit a 15mm hole but I have some spare black grommets designed for a 12mm hole.
I was thinking about using a forstner bit but I'm not sure whether I should be using a bit designed for metal instead.

I do also have access to a pilar drill as well.

 

[An Ankoù]

I decided to purchase a new fermenting bucket last weekend but the lid didn't come with a hole pre-drilled for an airlock grommet. (This one - https://www.the-home-brew-shop.co.uk/30-litre-fermenting-bin-with-litre-scale.html)

What's the best way of drilling the hole? The yellow grommet I picked up from the shop is designed to fit a 15mm hole but I have some spare black grommets designed for a 12mm hole.
I was thinking about using a forstner bit but I'm not sure whether I should be using a bit designed for metal instead.

I do also have access to a pilar drill as well.

Which size grommet does the stem of your airlock best fit?
There's no mystery to drilling the hoe, just use a drill of the correct size and then rub off any burrs with a bit of sandpaper.

 

[Hazelwood Brewery]

I first drill a hole and then enlarge it using a tapered reamer but if you have a tapered file it could do the job if you don’t rush it. Make the hole just big enough for the smaller end of the bung to fit with a piece of fine sandpaper wrapped around it so you can finish the job and obtain a good fit.

 

[MashBag]

Cone step drill.. Brilliant

 

[AndrewJB]

Drilled the hole yesterday using the 12mm Bosch Professional Forstner bit using a benchtop pillar drill. The lid was clamped down and there was wood under the lid in the drilling area.

The hole was far cleaner than I was initially expecting, looked as good as the pre drilled lids from Young's.