Advice please: cutting metal down pipe.... without

[ToughButterCup]

fekkin' it up...

 

I have some metal Lindab downpipe that needs to be cut - to install a diverter to a water butt.

 

I'm happy about marking it out (use a downpipe bracket) , but I'm hesitant about cutting it. 

 

Why? 

'Cos it's thin. Once it's been deformed (by me grabbing it and trying to keep it still) it never goes back into shape properly.

 

Anyone know how to cut it cleanly without bending it at the same time? 

 

I've looked on Tinternet and on Lindab's own site without much success. Hence this post.

[JohnMo]

https://tradewarehouse.co.uk/blogs/metal-guttering/how-to-cut-metal-guttering?srsltid=AfmBOopQ4EZ-p-gajPUNlRl2O4PXaEP0PWWypwK32BUxOrptG8Qb4rMp

[Gone West]

16 minutes ago, ToughButterCup said:

Anyone know how to cut it cleanly without bending it at the same time? 

I cut all our Lindab guttering system with a hacksaw as was recommended by Lindab.

[markc]

If you need to cut into the down pipe, holesaw for round holes, dremel type machine with a cutting disk for straight lines / squares etc

[ToughButterCup]

1 hour ago, Gone West said:

I cut all our Lindab guttering system with a hacksaw as was recommended by Lindab.

 

I've watched their videos and looked at the tradesman and thought they forgotten more than I know about how to do this. It's how they support the work that is so skilled. I'm going to have to set up a work table to hold the downpipe in place while I cut it.

 

I am ashamed deeply deeply ashamed to have to admit here in front of millions of people that I have not got a hacksaw. But now that I come to think about it one of my children will have stolen it.

 

Ah well it's an ill wind that blows nobody any good, so here's the excuse for another trip to the builders merchant. Knowing them they won't have the size I need will they? 😑

Edited 12 hours ago by ToughButterCup

[Gone West]

1 hour ago, markc said:

If you need to cut into the down pipe, holesaw for round holes, dremel type machine with a cutting disk for straight lines / squares etc

In the Lindab instructions they specifically say not to use power tools for cutting. The reason they give, is that using power tools destroys the galvanising around the cut. Apparently if hand tools are used then the galvanising is able to 'creep' back over the cut surface and maintain rust proofing. We didn't have any rust problems after six years.

[Gone West]

1 hour ago, ToughButterCup said:

It's how they support the work that is so skilled.

I just used a WorkMate with the jaws around 40mm apart and rotated the downpipe as I cut it with the hacksaw.

[Onoff]

Roll a thin bit of card around the pipe and mark with a Sharpie. That'll give you a dead square cut line. Then use the hacksaw to follow the pen line, rotating the tube as you go. As in you're almost scoring it. Take it easy and the saw will follow the groove when you finally cut the tube.

[SteamyTea]

I find a diamond cutting wheel on an angle grinder is pretty good for cutting thin metal.

 

I also have all my fingers.

 

 

[Onoff]

I think when zinc coated steel is cut, zinc oxide forms. This acts as a protective layer. Only really works on thin sheet edges. Same with a light scratch. 

 

Won't work on say the cut end of a galvanised RSJ. Best thing for that is a Zilt stick applied with a porta pack. 

 

Most now use  so called "cold galv" out of a rattle can. Zinga is very good. 

Edited 8 hours ago by Onoff

[SteamyTea]

30 minutes ago, Onoff said:

Zinga is very good

A Zinga Gazelle was a car, taking you back to your Rootes.

Edited 7 hours ago by SteamyTea

[SimonD]

6 hours ago, ToughButterCup said:

It's how they support the work that is so skilled.

 

I've used two methods. One was with a really old work bench where the surfaces could be angled to 45degrees and the tube would just rest in the pocket. The other was just to screw some 4 x 2 together at right angles and gently hold the pipe against those. Eventually you'll get the feel of very light strokes with the hacksaw and you can hold both the gutter and down pipes by hand on any bench and it works fine.

 

For the holes in the gutter, you need to get yourself some tin snipps and a decent dead blow hammer for the edges.

 

Installation instructions attached.

 

Have fun. It's lovely material to work with.

Rainline-Assembly-Guide.pdf