Drilling Galvanised Steel Tank

[Paulus]

I have just been out to look at a job where the customer wants a shower pump installing. She has a galvanised steel water tank that looks in vey good nick. I have never drilled one of these before as I would usually replace the tank but this one has been built into the top of the airing cupboard and goes part way into the roof space. I would have to basically destroy half the bathroom to get the damned thing out.

I propose using a hole saw, any tips/ advice guys.

 

[gassafe]

A hole saw in good condition should do it fine!

I use thos jg tank connecters now! Nice rubber seal on them, hand tighten only, there brilliant!

 

[justlead1]

Hi. Had a similar situation on my own property. The cold feed to shower meant drilling a hole in the galv cistern. However being short of time i thought i would just us a siphon loop. (cold feed up and over cistern and down to bottom of cistern on inside) Pushed the air out using mains and a way it went. This temporary arrangement has lived for 24 years without fault, but i must attend to it soooooooooooon.
Good Luck

 

[kay-jay]

Q cutters are the best for steel but pricey. I borrowed one to cut a hole in a ss stockpan to use for brewing beer.

 

[Destroyer2813]

Check out the capacity of the tank and the output of the shower as little tanks in ac above the cylinders are normally small

 

[gassafe]

Hi. Had a similar situation on my own property. The cold feed to shower meant drilling a hole in the galv cistern. However being short of time i thought i would just us a siphon loop. (cold feed up and over cistern and down to bottom of cistern on inside) Pushed the air out using mains and a way it went. This temporary arrangement has lived for 24 years without fault, but i must attend to it soooooooooooon.
Good Luck

How does this work lol! Surprised it does not airlock constantly!! Surely it would air lock on the bend above tank, as the water level would drop back to tank water level everytime?

 

[Irish]

How does this work lol! Surprised it does not airlock constantly!! Surely it would air lock on the bend above tank, as the water level would drop back to tank water level everytime?

Surely it's the same as siphoning a cylinder once is got no air in it and its full of water how can it get air locked ?

 

[PETE 123]

Could you not just t into a feed on tank outlet?

 

[Paulus]

Could you not just t into a feed on tank outlet?

Not really, Pete, a pump needs a deicated hot and cold supply.

Thanks for all the useful advice everyone, I feel a bit more confident about doing the job now. Much appreciated.

 

[stevetheplumber]

weve done the syphon trick before now and yes it works best to tee a fill point in incase of problems a filling loop would possibly do the trick

 

[gassafe]

Surely it's the same as siphoning a cylinder once is got no air in it and its full of water how can it get air locked ?

Yes I can see it working once primed & running etc... But surely when the shower is turned off, the loop that goes above the tank would not stay full of water above tank water level!? So then, that bit would air lock I thought... Unless I'm imagining it wrong...

 

[kay-jay]

Yes I can see it working once primed & running etc... But surely when the shower is turned off, the loop that goes above the tank would not stay full of water above tank water level!? So then, that bit would air lock I thought... Unless I'm imagining it wrong...

I would have thought that it would stay full of water in the same way that any siphon loop does when draining for example, until the cistern empties and the pipe drags in air....

I would imagine that when the shower valve turns off that negative pressure remains thus creating the vacuum required to stop the loop 'emptying' back into the cistern.

 

[PlumbBobBob]

:iagree:

 

[Ermintrude]

Me too!

 

[tamz]

So then, that bit would air lock I thought

It can't air lock without air. Think of it like putting your finger over a straw
It might move slightly but won't/can't empty. Only time air could bet in is if the water level in the tank fell below the pipe. It would then need primed again to work.

 

[Paulus]

Hi. Had a similar situation on my own property. The cold feed to shower meant drilling a hole in the galv cistern. However being short of time i thought i would just us a siphon loop. (cold feed up and over cistern and down to bottom of cistern on inside) Pushed the air out using mains and a way it went. This temporary arrangement has lived for 24 years without fault, but i must attend to it soooooooooooon.
Good Luck

Thanks for this justlead.

I have been putting this job off and getting on with the rest of the bathroom. For the first time I don't feel very confident in drilling this tank as nobody came back to say that they have actually done one. I received advice from a local specialist who had also never drilled a steel tank and he sold me a cutter that he said "should work using plenty of oil".

I think I will go with justleads idea. I don't want to get part way through and finish up with a hole that is too small that I will then have to find some way of plugging.

 

[tom609]

Get a new starrat drill bit from the iron mongers it will go through like knife through butter

 

[Paulus]

Get a new starrat drill bit from the iron mongers it will go through like knife through butter

Will I get a 27 mm bit?

 

[Paulus]

Forget the last question. I looked them up on the interweb and found a 29mm bit that will do the job. Thanks tom but I will come back and haunt you if it goes pear-shaped. Will let you know.

 

[Reg Man]

Many years ago this is the type of cutter we used.

 

[Paulus]

Get a new starrat drill bit from the iron mongers it will go through like knife through butter

Fantastic, superb, brilliant, amazing.

Job done in less than 10 minutes and nice clean cut. If you haven't got the message I'm over the moon with your advice tom.

Thank you once again.

 

[tom609]

woo hoo

 

[Gray0689]

Thanks for this justlead.

I have been putting this job off and getting on with the rest of the bathroom. For the first time I don't feel very confident in drilling this tank as nobody came back to say that they have actually done one. I received advice from a local specialist who had also never drilled a steel tank and he sold me a cutter that he said "should work using plenty of oil".

I think I will go with justleads idea. I don't want to get part way through and finish up with a hole that is too small that I will then have to find some way of plugging.

Hole saw and drill it no problem done it lots if times

 

[mike-c]

Many years ago this is the type of cutter we used.

I'm sure that's the cutter that is supplied from IKEA to cut out the tap holes on their stainless steel sinks.

 

[Paulus]

Hole saw and drill it no problem done it lots if times

Now you tell me. Where were you last week? :90:

 

[stevetheplumber]

forgot to say remember to get every bit of swarf out of the tank we used a big lump of putty to pick it all up thinking about it we used putty for a lot of things back then

 

[stevetheplumber]

the drawing doesnt show the bits sticking out from where the stilsons had been used on it
im sure there was a name for these cutters

 

[turnpin]

the drawing doesnt show the bits sticking out from where the stilsons had been used on it
im sure there was a name for these cutters

I think the drawing shows the type electricians first used I know the plumbers type you are thinking of I knew these as Cookes cutters I think I still have some in the shed but finding them well thats another story...regards Turnpin

 

[Paulus]

forgot to say remember to get every bit of swarf out of the tank we used a big lump of putty to pick it all up thinking about it we used putty for a lot of things back then

Thanks steve, I used more up to date technology, a magnet!

 

[kay-jay]

i mentioned the q cuttewrs in earlier post they cut holes burr free, noi need for magnets or putty lol

here they are

https://www.cromwell.co.uk/QMX0451124B

 

[Gray0689]

i mentioned the q cuttewrs in earlier post they cut holes burr free, noi need for magnets or putty lol

here they are

https://www.cromwell.co.uk/QMX0451124B

And these can cut a galvanised tank
Bit thicker than sixes shown!

 

[kay-jay]

I cut a stainless steel stockpot with one. It had a much thicker wall than a galv tank

 

[Gray0689]

I cut a stainless steel stockpot with one. It had a much thicker wall than a galv tank

Stainless will cut easier than galvanised imho

 

[Micky T]

You need a top quality steel hole cutter, Bosch or similar

 

[Micky T]

I like that, if been plumbing for 48years but haven't thought of that one as a temp' although I always drain down cylinders by syphonige( mains filled hose pipe attached to copper pipe placed in cylinder and hose chucked out of window.

 

[WHPES]

I seem to think that a galvanised tank or unlidded plastic tank without byelaw kit does not meet legionella hygiene requirements so would be illegal to use for a cold supply for a pumped shower. (Perhaps this is just for commercial work - Please correct me if I am wrong)