Lead burning/tack welding torch - boiler flue through lead roof

[Tim S]

Hi

At some point I'll need to take a concentric room sealed boiler flue (and maybe a soil stack vent) out through a flat lead roof.

To this end, I've decided to, for a 100mm exit:

1) Cut a 70mm hole in the lead;

2) Cut a 150mm hole in the wood (combustable material clearance gap of 25mm all round)

3) Work the edge of the lead round the hole up to form a circular lip about 1-2cm high, and enlarging the hole to about 110mm - I've cold worked lead before, so with some adjustments, I'm sure this is possible

4) Make a slightly conical lead tube about 100mm long, 120-130mm at the base at 100mm at the top.

5) Sit tube over lip round hole in roof and put stainless steel flue pipe through.

6) Use flue manufacturer's rubber vertical seal collar to seal between flue and lead tube.

[mark]

Isn't this what you're after?

[Tim S]

mark coughed up some electrons that declared:

Perhaps - although I could use a 5 degree (or zero degree) version; the roof has very little pitch.

However, this looks interesting:

need to bond it to the roof. I'll give them a ring and see what they say.

Thanks for that pointer.

Cheers

Tim

[geoff]

In message , Tim S writes

I've prolly got one that will do what you need

I have a friend who is a lead roofer who will be able to tell us exactly

[Tim S]

geoff coughed up some electrons that declared:

Look forward to it - ta.

I expect "others" might bond a lead slate on with some rubber scunge - but welding seems better.

Cheers

Tim

[geoff]

In message , Tim S writes

I have one of these (with a mapp gas cylinder on)

I have a hand held torch which attached to a gas cylinder (what the big boys use)

[John Rumm]

Looks like the sort of thing used here:

[John Rumm]

I expect that is what this one is, although they have the wrong photo:

use the same photo for all the variations you will notice)

[Dave Plowman (News)]

I had a small split on one corner of a lead cover over some pipe ducting which was easily accessible (being on a roof terrace) so decided to have a go and got good results using ordinary elctronics leaded multicore and a small 'jewellers' butane blowlamp. I practised on some scrap first. Lead isn't that good a conductor of heat. But you'd need a still day for this to work easily.

[Tim S]

Dave Plowman (News) coughed up some electrons that declared:

Hi Dave

That's interesting... That would mean that soft soldering (aka the way lead pipes were joined) would also work. For this application, I think a few tacks of soft solder would be more than sufficient.

Now I'm going to walk to the plumber's merchant and ask for a stick of plumber's metal, tallow and a moleskin just to see their reaction ;->

No, perhaps not, I'll look on t'internet as usual...

But you did give me an idea - soldering would be safer than lead burning (less chance of unwanted holes in the roof).

Cheers

Tim

[Bruce]

As this is uk.d-i-y ...

... you have to catch your own mole. ;-)

[Dave Plowman (News)]

My local TP stocks all of these. But you don't need tallow or moleskin for the sort of thing you're doing. They're needed to wipe a neat finish on a joint.

[Alang]

I used to do plumbed joints on lead sheathed cable when I first started work (1960s) . Used a very large (2lb) copper hatchet style soldering iron heated with a paraffin blowtorch. It's quite unwieldy until you get the knack but easily handles jobs like that. Only ever did a couple as we went over to joint boxes after that thankfully.

Indeed it would.

I used to have a gas blowtorch with a soldering bit attachment that would be ideal for joining sheet lead. Had a look on the internet but there doesn't seem to be anything like it now.