New hole in galvanised tank

[Wingedcat]

Hi, I need to make a new hole in a galvanised tank to fit a 22mm tank connector. Any thoughts on the best way of doing this? I was thinking

bearing in mind the pipe is 22mm, the tank connector will necessitate, I would think, another 3mm or 4mm to the diameter of the hole, so what size hole will I need to drill?

Will the 25mm electrician's holesaw be best do you think? Or can anyone think of a better way of doing this?

Thanks

[Andrew Mawson]

thinking

If it is a 'domestic' galvanised tank, then they are relatively thin and a hole saw should work fine. If it is more 'commercial' then they can be up to 1/4" thick and quite a pain to cut (yep been there !)

If it is domestic, in your own home, and you plan on being there a year or two then I'd seriously consider changing the entire tank for a modern plastic one - they make quite a mess when they rust through!

Obviously the issue of size is one for you to measure and choose accordingly.

AWEM

[Wingedcat]

Thanks for the advice. I'll have a look at the tank to see if it is showing signs of rusting through, but I don't really fancy replacing it as it is squashed into the airing cupboard directly above the HW tank at the moment so I would be very surprised if a replacement plastic version would slot into the same (very limited) space.

Regarding the size, I suppose I want to avoid buying the plumber's holesaw kit (with holesaw sizes of 19, 22, 29, 38, 44 and 57 mm)

If the electrician's kit (with sizes of 16, 20, 25, 32, 40 and 51mm) will contain the correct size holesaw for a 22mm tank connector. Or vice versa.

[Dave Plowman (News)]

Q-max punch. Costs about a fiver and is easier to use than a hole saw.

[nightjar]

The thread should be 7/8" BSP, which is what the 29mm hole saw in the pumbers' kit is for.

Colin Bignell

[The Natural Philosopher]

That cheap? If so, go for it. By far the best option in sheet metal.

[Dave Plowman (News)]

Rapid price. Of course you'll need an allen key too if you've not got a suitable one.

[Wingedcat]

Thanks all, very helpful. Will go for the 29mm Q Max punch. I have an

8mm allen key from when I had to remove the brake caliper on my Ford Escort, so no worries there.

[Guy King]

The message from "Wingedcat" contains these words:

Bet that's a 7mm!