Chimneys and Deckheads

[Moley]

Have searched but can't find what I want, so is there a relevant thread (Dan?) or can anyone advise?

 

I've started putting my ceiling / deckhead up. I'm using T&G pine (painted both sides before fixing). The stove pipe goes up through a cast iron collar, gaps plugged with pseudo-asbestos rope.

 

Will that cast iron collar stay cool ?

How far back from it should I cut my polyurethane insulation (presumably I can stuff any gap with rockwool) ?

How close can I bring my pine T&G, and how do you trim or finish neatly ?

 

Any advice / pics would be appreciated, let then puns begin.

 

Ade.

[John Orentas]

Hi Moley.

 

Although the cast collar will get hot it will never reach a temperature that could ignite anything, leave a gap of an inch or so from any woodwork and insulation panels and you will be safe, filling the gap with high temperature insulation you will be doubly safe.

 

I fitted a brass plate with an aperture for the stove pipe to cover the gap on the deckhead.

[Guest]

Hi Moley.

 

Although the cast collar will get hot it will never reach a temperature that could ignite anything, leave a gap of an inch or so from any woodwork and insulation panels and you will be safe, filling the gap with high temperature insulation you will be doubly safe.

 

I fitted a brass plate with an aperture for the stove pipe to cover the gap on the deckhead.

Same here.

[Moley]

Thanks John, guessed as much but thought I'd ask to be on the safe side.

 

My late father was very much into clock restoration and building movements from scratch.

I'm sure I should be able to find brass sheet, or a longcase clock dialplate or chapter ring somewhere in his garage or loft.

[denboy]

try a brass porthole liner for the inside

[Alastair]

The barge that used to be on my mooring burnt out because ceiling timber caught fire from the stovepipe.

 

Surround it with Rockwool, that will keep things safe.

[ChrisPy]

try a brass porthole liner for the inside

the proper job is only about £13 from Midland

[Moley]

Thanks for the advice and tip.

 

If the stove pipe is separated from the cast collar by fire rope (or whatever it's called), how warm does the collar actually get? Is any heat transmitted from the stove pipe, or does it only get warm from convected heat from the stove itself?

[Bones]

Thanks for the advice and tip.

 

If the stove pipe is separated from the cast collar by fire rope (or whatever it's called), how warm does the collar actually get? Is any heat transmitted from the stove pipe, or does it only get warm from convected heat from the stove itself?

 

 

I will check my collar and let you know - the fire isn't alight yet! I have cut back the tongue and groove on my ceiling quite a long way, and have put a square of fireboard on the ceiling which the pipe goes through.

 

the stove pipe from the stove up to the collar does get warm - I have hugged it on more than one occassion! I think it does get too hot to hug... but I can't remember! I will check that out as well.

[stuart]

Thanks for the advice and tip.

 

If the stove pipe is separated from the cast collar by fire rope (or whatever it's called), how warm does the collar actually get? Is any heat transmitted from the stove pipe, or does it only get warm from convected heat from the stove itself?

 

Obviously it does depend upon how hot the fire is!

 

Mine gets fairly hot - you wouldnt want to touch it for long - but not enough to burn you.

[Guest]

The cast collar on ours doesn't get very hot to my mind, and i am paranoid about that.

[John Orentas]

The stove-pipe can be seen as part of the heating system and a significant part of the boat heating comes from the pipe, however anyone who has ever tried to produce a thermal path between two metal objects will know the only effective way is to weld them together, so very little heat is transfered directly from stove to pipe or pipe to collar, the pipe gets hot because of the hot gasses inside it.

 

The collar does not get as hot as you may expect partly because it's contact area with the gas is small and partly because the gas has cooled by the time it gets up there.

 

What worries me is the modern misguided trend to use double skinned flu-pipe, presumably to help the 'drawing' of the combustion but also preventing the pipe from giving up it's heat, it will also inevitably mean that the gas will still be very hot where it meets the chimney collar. I would never use the stuff.

Edited March 18, 2006 by John Orentas

[DHutch]

Our coller donest get that hot at all, even after a full day, you can easly hold your hand on it.

 

We have a cast iron (invertered) drain pipe for a our flu, and ive said before, which is sealed with 300C silicon (prevously glass rope and fire cement)

- Theses a good 8/10mm thickness of silicon between the pipe and the coller, so heat transfer is limited.

 

The T&G has been cut back to a 10" square, which has been replace with fireboard.

- And i beleave the polystreine has then been cut back a little further, and is replace with rockwool or glassfibre.

 

 

Daniel

[Bones]

Our coller donest get that hot at all, even after a full day, you can easly hold your hand on it.

 

We have a cast iron (invertered) drain pipe for a our flu, and ive said before, which is sealed with 300C silicon (prevously glass rope and fire cement)

- Theses a good 8/10mm thickness of silicon between the pipe and the coller, so heat transfer is limited.

 

The T&G has been cut back to a 10" square, which has been replace with fireboard.

- And i beleave the polystreine has then been cut back a little further, and is replace with rockwool or glassfibre.

Daniel

 

 

I have done the 'hug test' on my stove. today was a good day to do it because I was cooking (which means the stove is about as warm as anyone else's. The collar on the outside of the boat was warm to touch. The pip on the inside was certainly warm and I didn't enjoy hugging it with just a t-shirt on, but did with a jumper. My pipe, unlike Daniels, is pretty tight fitting into the colour, and I also have the 10" square of fireboard as Daniel has. I also cut the polystyrene back as far as I could (further than the tongue and groove). I didn't replace it with anything.

 

I actually found it quite hard to cut the tongue and groove.

 

Today the stove was rather warm to say the least - warmer than it is usually - but mainly because I needed to cook lunch quickly.