Cut a hole in plastic tank.

[assuhors]

I need to cut a 29mm hole in my plastic cold water tank to supply a power shower,what is the best way,thanks in advance.

 

[JPC]

a hole saw and a drill

 

[namsag]

Bit of 22mm Pipe heated with blow lamp and wiggled about to make correct size hole is the easiest and most popular, If you don`t own a hole saw

 

[assuhors]

I see Screwfix do a 29mm holesaw so of in the morning to get one.

 

[JPC]

namsag, is that what they tought you a college ?

 

[breezer]

suggestion.

this pipe that the hole is for, if it has a locking nut inside the tank (tank connector) dont forget the nut has to fit n the inside of the tank, so dont drill the hole too low

 

[ChrisR]

I never use a holesaw now because the bits get stuck under float valve washers etc.
A sharp flatbit is quite good because it cuts a long piece of "swarf".

I don't know of any "damage" or weakening that's likely to result from using a hot piece of pipe. All and sundry will tell you it's a bad idea, but without proper explanation. Remember the tank's hot moulded! It's the method most plumbers use, and I've yet to see any sign of cracking as a result.

The hot supply outlet should be higher than the cold supply outlet, so that the hot runs out first, so you don't scald.

 

[PlanetThanet]

Hi

I suppose,as an RGI , you should go by the mantra 'follow the MIs ' and use a hole cutting tool.

http://www.uk-plumbing.com/pc20r-rectangular-water-tank-665x490x510mm-p-1638.html


Swarf? use a vacuum cleaner or turn it upside down.

Thanet.

 

[namsag]

JPC and your point is. back yourself up . And i was taught at college not tought And speaking of college was it a 6 or 8 week course you done

 

[numpty1]

we all have done the hot pipe bit,nowadays i use a holesaw because the hot pipe method has cost me tanks in the past depends on the ambient temp too cold[tank has been sitting outside] and their is a good chance it will split,not a prob in the summer.

 

[namsag]

Done hundreds and hundreds at everytime of year and every temp WHY would it split. Why has it cost you tanks ?

 

[numpty1]

namsag wrote

Why has it cost you tanks

because the astards have split in the cold weather must of split around a dozen cws/heat tanks.prefer to use a holesaw nowadays also removing the burrs from inside the tank can be a finger losing moment with a stanley on cold days.

 

[Softus]

Follow the MIs - use a hole saw.

There aren't that many different sizes that are needed, and it's actually easier than heating up a bit of tube and arsing around trying to get the hole the right size.

There seem to be people who think that being a plumber means you have to do everything with some copper and a blowtorch. I guess it's these people who install rigid copper pipework onto brass tap connectors, in new builds, then struggle to do them up tight, and never get to see the propertion of them that leak afterwards.

 

[namsag]

Numpty , we where talking about this other day in merchants only one guy that uses a hole saw out of a dozen of us and know none on board ever used a saw. Nobody has ever had one split or damage on them. You must ber unlucky and no real need to use stanley knife ,while plastic still semi molten any excess pulls straight off

 

[numpty1]

namsag i know loads of blokes who swear by the hot copper tube method,i also know a few who refuse to use anything but a holesaw.holesaw users may be in the minority but we read the instructions that some manu supply, not to use hot pipe is clearly stated,you carry on with the hot pipe if it works for you and the majority of plumbers good luck but as i said my preferred method is a holesaw.